00:00:00BOHNING: Professor Dewar, I know that you were born on September 24, 1918 in
Ahmednagar, India. Could you tell me something about your parents and your
DEWAR: Yes, my father was in the Indian Civil Service. I was in India until I
was not quite eight. Children at that time had to be sent home to school because
00:01:00there weren't any schools there. It was a curious situation. It took a few weeks
by sea, and it was very expensive. There wasn't time for children to come back
for the holidays. People in India didn't return until they'd saved up enough
leave to make it worthwhile, which was roughly once every ten or twelve years.
So the normal thing was for people to send their children home and possibly not
see them again until they were eighteen. My father died when I was nine and a
half and my mother came back to England, so it didn't apply to me. It did to my
sister. She was sent home at the age of eight and they didn't see her again for
BOHNING: She's older than you?
DEWAR: She's about twelve years older.
BOHNING: Are you the only two in the family?
BOHNING: Do you have any early recollections of India?
DEWAR: I remember quite a bit about it. I had a strange upbringing, because
00:02:00there were no other white children in the place at all. My father was a District
Commissioner in a fairly remote area around a place called Chanda. Have you seen
the film, "A Passage to India?" The situation was like that except that there
were many fewer white people. There were about thirty white people there. I was
playing bridge at the club when I was six. In fact, I never met any children at
all until I was eight. It was quite a shock, because I was sent home first to
stay, not with family, but remote acquaintances. That was a shock, being sent
away from my parents for the first time. Then, just when I was getting used to
it, I was sent out to boarding school, and boarding schools there were extremely
rough and uncivilized places. I had a hell of a time. It was the first time I'd
met any children, anyway.
BOHNING: Where was this in England?
00:03:00DEWAR: A school called Copthorne. It's halfway between London and the English
Channel, south of London.
BOHNING: Is there any reason that one was selected to send you to?
DEWAR: I really can't remember. It was quite a good one, particularly because it
was one of the standard prep schools for getting to Winchester. I think that my
mother hoped I'd get to Winchester, which was a leading public school in Britain scholastically.
BOHNING: How long were you there?
DEWAR: I was there for five years.
BOHNING: What kind of education did you have there?
DEWAR: The standard one for Britain at that time. Mainly mathematics, Latin and
00:04:00Greek. At that time the "classics," Latin and Greek, were very strongly
emphasized in all private schools. In fact, I studied classics until I was
halfway through my time at Winchester.
BOHNING: I'm just trying to get some dates correct. You went back to England in
1926. Is that correct?
BOHNING: And how long were you in the boarding school?
DEWAR: Until 1931, when I got the scholarship to Winchester. I got the first
scholarship, which surprised everyone greatly. The reason I got it was quite
entertaining. Winchester had a special scholarship examination in which they
emphasized originality. One of the questions I was asked was, "What do you think
00:05:00will be the most exciting invention in the next fifty years?" I had taken to
reading science fiction, and had just come across a splendid idea which I duly
reproduced. Of course, the examiners hadn't read this, so they thought my idea
was original. I'm sure that did the trick. [laughter]
BOHNING: What did you tell them?
DEWAR: Well, the idea was that sound waves become weaker with time but never
totally disappear, so it should be possible in principle to develop a sound
detector which would pick up sounds from anytime in the past. I had several
examples of things that would be nice to hear, such as Caesar addressing his
army before his battles and so forth. [laughter]
BOHNING: That's very interesting. What can you tell me about Winchester? You
said it had the best reputation.
00:06:00DEWAR: It was the top school scholastically. It's also exceptional in that the
Scholars there were segregated in College. This was set up as a charity in about
twelve hundred and something by a man called William of Wykeham, to provide
education for poor people. The Scholars lived together in College and for them
everything was practically free. Since Winchester was the top school
scholastically in Britain, scholarships there were the most sought-after in the
country. Not surprisingly, the Scholars were extremely bright people. A friend
of mine, who was a biology Master there for a time, tried running intelligence
tests on them. Over the period he was there, something like ten years, he didn't
00:07:00find a single scholar who was not off the scale. Actually that isn't quite true.
There were two who were just marginally on the scale. One of them was a
contemporary of mine and everyone thought him extraordinarily unintelligent.
There was, however, a bad side to it. Putting a whole lot of exceptionally
intelligent people together had the effect of completely destroying their
self-confidence. When you are surrounded by geniuses, you don't think of
yourself as being particularly intelligent. Most of them indeed ended up in the
civil service, which provides nice safe jobs. Few did anything at all dramatic.
BOHNING: You concentrated again on the classics at this point.
DEWAR: I did for the first two and a half years. I had in fact become totally
converted to chemistry early on, by accident. There was a library in College to
00:08:00which people sold their old books when they left and new arrivals could buy them
very cheaply. This was a big help because many of the Scholars were by no means
rich. In my first term I was there buying books I needed when I saw one on
chemistry. I had always wondered what chemistry was about, so I bought it and I
was hooked from the word go.
BOHNING: Do you remember which book it was?
DEWAR: No, it was just a school textbook. It's vanished, I'm sure.
BOHNING: Had you had any previous exposure to science, chemistry in particular?
DEWAR: The thing I'd been reared on was a wonderful book called the Children's
Encyclopedia. It was a huge work, almost the size of
the Encyclopedia Britannica. I think there were fourteen volumes, each with over
a thousand pages. It was a great big thing. It was moreover edited by an
00:09:00absolute genius called Arthur Mee who clearly knew just what children were like.
It was full of information, a lot of it totally useless. It had articles on
everything you could imagine, from art to music to science, everything. It was
full of pictures and illustrations. I remember reading that almost exclusively
for years and years.
BOHNING: Did you have any chemistry sets or any laboratory experience in your
education up to that point?
DEWAR: No, I didn't.
BOHNING: So it was just through reading that you acquired that interest.
DEWAR: Yes. In fact, the first national examination I took was a thing called
"The School Certificate Examination," which I took at the age of sixteen. I
hadn't done any chemistry. I had special permission to take the exam, which
00:10:00covered both chemistry and physics. I duly passed it, but it was the first time
I'd ever carried out any experiments, because they had a lab test.
BOHNING: What kind of experiments?
DEWAR: I remember one involved a Wheatstone Bridge. We had to measure the
resistance of something. Now, I'd never seen a Wheatstone Bridge, and I couldn't
remember how it functioned. I eventually did get the thing wired correctly by
simply connecting the resistances in all possible combinations until I got it to
BOHNING: Once you were hooked on chemistry, what changes occurred in terms of
the courses you were taking?
DEWAR: I stuck to classics for two and a half years before I finally gave up.
I'm really very glad I did, because I hated it. I was never really any good at
00:11:00it, but I think it's a wonderful subject. I have always felt that it should be
taught at all schools, because it provides an extremely good logical education
right from the word go. Latin is a very complicated language, with hundreds of
rules and hundreds of exceptions to the rules. You have to know exactly what
rules, and what exceptions to them, to apply in each case. It is also something
which most children hate, so they learn early on to work hard at something they
don't like. The third advantage is that it's totally useless to most people, so
you don't run the risk of turning people off at an early age from something that
might be useful to them later on. I think everyone should be taught Latin. I
stuck to it for two and a half years, simply because I thought it would do me
00:12:00good, before I finally surrendered and changed over to science.
BOHNING: What did you start doing in science when you changed over?
DEWAR: Just the standard school courses.
BOHNING: Again, I'm trying to get the dates straight. This would have been when?
DEWAR: I went to Winchester in 1931, and I was there for five years until 1936.
I went well beyond the school level in chemistry. There was a school science
library and I got permission to use it quite early on. I read everything there
was in it. That included the standard organic text used in universities.
BOHNING: I was going to ask if there was anything specific in that reading that
00:13:00DEWAR: I was totally hooked on organic chemistry by the time I got to Oxford.
Two books, one by Schmidt and one by [Paul]
Karrer were then the two standard organic textbooks
used in universities.
BOHNING: Were you doing any organic experiments along with that reading?
DEWAR: I did in my last year at school, because by that time my teachers
realized I was beyond school level, so I spent a lot of time doing experiments
in the lab with the chemistry master.
BOHNING: Were you doing synthetic work?
DEWAR: I don't really remember. I remember doing studies of the kinetics of
various reactions, for example, formation of urea from ammonium cyanate.
BOHNING: Were you already looking at Oxford University? Was this your goal, to
00:14:00move from Winchester to Oxford?
DEWAR: Yes, and this for purely practical reasons. I went to Oxford--to Balliol
College in particular--simply because my mother had very little money. My father
had died young, so she had only a small pension from the civil service. It had
been a struggle for her getting me through. I don't think she could have
supported me through a public school education if I hadn't got the scholarship
to Winchester. At Balliol, they not only had an open scholarship, but they had
also had a special scholarship for students from Winchester. I was also able to
get a School Exhibition. So collectively I was able to support myself at Oxford.
00:15:00So that is why I went to Balliol.
BOHNING: You started at Oxford in 1936 and you had already decided to major in
chemistry. What kind of education were those four years at Oxford, in terms of
DEWAR: Oxford was unique in the sense that the undergraduate chemistry course
there was nothing but chemistry, not even physics and mathematics.
DEWAR: Every other university, including Cambridge, did have such courses, but
Oxford had nothing but chemistry. England also had a strange system, and they
still do, of having everything determined by a single examination at the end of
00:16:00the course. Everything depends on that. If you are sick, it's just bad luck. In
the chemistry course you could get a B.A. But you could also stay a fourth year
and do research. Then you could get a B.Sc. as well. You had to stay that fourth
year to get an honors degree, which was really a four-year course. I finished
the first part just before the outbreak of World War II, and I did my year's
research during the first year of World War II.
BOHNING: Who were some of your professors?
DEWAR: [Sir Robert] Robinson was the Professor. In Britain at the time, there
00:17:00was only one professor per department, and he was the Professor. The other thing
was that at Oxford there were no lectures. Well, there were lectures, but few
dimwits went to them. All teaching was done by the so-called tutorial system, in
which you had a tutor who each week assigned you a subject to write an essay on.
Once a week you'd go and spend an hour going through it with him.
BM-WING: What about laboratory work?
DEWAR: That they did have, yes.
BOHNING: What types? Did you have both organic chemistry and physical chemistry?
DEWAR: Yes, indeed, and also inorganic chemistry.
BOHNING: What about analytical?
DEWAR: Analytical chemistry was not a recognized branch of chemistry in England
at that time.
00:18:00BOHNING: In this country at that time, analytical chemistry was certainly a
large branch of chemical instruction.
DEWAR: Right, right. But it never had been in Britain. I don't know what the
situation is now, but certainly up until the time I left, analytical chemistry
was not regarded there as a branch of chemistry.
BOHNING: That's interesting. Tell me something about Robinson. You had
associations with him for some time, but what was he like in those early days?
DEWAR: I saw very little of him. The only lectures I went to at Oxford were a
series by Robinson. You couldn't get the information otherwise. The series by
[Nevil Vincent] Sidgwick fell in the same category because he was writing a book
at the time. It was supposed to appear at any moment, but it hadn't appeared. In
fact, it didn't appear for another ten years.
[laughter] Those were the only two I went to. But I got to know Robinson very
well later. My year's research for my bachelor's degree I did with [F. E.] King,
00:19:00who was my organic tutor at Balliol College. I had two tutors. The inorganic
tutor was Ronnie [R. P.] Bell. Everyone was drafted during the war, and I was
told to stay up at Oxford and work on war problems. So I did a D.Phil., which is
what Oxford calls the Ph.D. just to be different. I did that with King. Robinson
was annoyed at my failure to work with him. I pointed out that he was never in
Oxford, and I needed a lot of supervision and teaching in lab work because I was
never any good in the lab. I said that I'd stay and work with him later, which I
00:20:00did after I'd finished my D.Phil.
BOHNING: Given the kind of work you were into later on, what was your
DEWAR: I got none at Oxford, but fortunately at that time the levels at school
were very much higher than they were here then or are there today. I was good at
mathematics, so I was in the sixth form, the top form. I was really doing quite
advanced things, like partial differential equations, matrix algebra, and that
sort of thing. So I really had a pretty good background in mathematics. But I've
always felt the lack of having more; it has always been a disadvantage to me.
00:21:00BOHNING: At Oxford was it organic chemistry that attracted you the most, as
opposed to physical chemistry?
DEWAR: Oh, absolutely, from the word go. Ronnie Bell made desperate efforts to
interest me in physical chemistry by making me study statistical mechanics and
quantum theory. I simply rejected the lot. I wish now I hadn't. [laughter]
BOHNING: Yes, considering what happened later on.
DEWAR: I was convinced that physical chemistry was awful. [laughter]
BOHNING: Was your first exposure to quantum mechanics?
BOHNING: Did you get any exposure to Huckel theory at that time, or was it still Pauling?
DEWAR: Only basic quantum mechanics. I didn't get on to Huckel theory or
00:22:00molecular orbital theory or anything like that. I was not exposed much to
resonance theory. Robinson objected to it, but Robinson's classical electronic
theory is in fact equivalent to resonance theory. The two are just different
ways of describing the same thing.
BOHNING: I want to look at some of the work that you were doing while you were
at Oxford, but before we do that, what about your wartime experiences? What was
it like being at Oxford during the war?
DEWAR: Oxford was insulated from the war, because there was a sort of unofficial
agreement between Germany and Britain that Germany wouldn't bomb Oxford or
00:23:00Cambridge and Britain wouldn't bomb Gottingen or Heidelberg. There was only one
exception. One day a Polish pilot couldn't find his target in Germany. The Poles
never brought any bombs back, so he flew around until he saw a city which
happened to be Gottingen, and he dropped all his bombs on it. The Germans
retaliated by dropping some bombs on Cambridge. The misunderstanding was sorted
out through Switzerland or somewhere, and nothing happened again. We had lots of
air raid warnings, but nothing ever actually happened.
BOHNING: What kind of war-related work were you doing? Is that when you were
working on antimalarials?
DEWAR: I started by trying to make new explosives. That wasn't very successful,
00:24:00because at that time, Woolrich Arsenal was the center for explosives in Britain,
and they were outraged at anyone infringing on their preserve. The fact that
there was a war on didn't seem to them to be any excuse. They retaliated by
never testing any of the things I sent them. In fact, one of the compounds I
made probably would be quite a good explosive, judging by later calculations at
the Piccatinny Arsenal. That was the first thing.
Then I got on to making sulfa drugs. I made several derivatives of pyrazole, but
they turned out to be so insoluble that none of them could be tested.
00:25:00Then I got on to antimalarials. I was given the job of trying to explore new
heterocyclic systems. I made a huge number of compounds, none of which turned
out to have any toxicity to any microorganism. Then I got on to the penicillin
project. I was given the job of making an analog of penicillin. The only trouble
was that the accepted structure for penicillin at that time was wrong. So I was
actually trying to make an analog of something else, and I didn't succeed in
making it anyway. About that time the war came to an end, so all I can say is
that I didn't actually hinder the war effort. [laughter] But I nearly did. I
used to get directives from some central organization, advertising jobs that I
was asked to apply for. I never replied. One day, however, I got a particularly
impressive-looking offer. It was a job as chief technical advisor for the
00:26:00erection and operation of factories near London for filling shells and bombs.
There was a little note at the bottom saying, "In the event that you do not
apply for this position, you will be liable to imprisonment not exceeding two
years' penal servitude or a fine not exceeding £10,000 or both!" This I was a
bit shaken by, so I took it Robinson. I must admit I was a bit put out, because
he just turned white with rage and said, "The fools!" He needn't have put it so
bluntly. He literally grabbed it from me, and I was left alone for the rest of
BOHNING: Could you explain a little bit about the D. Phil. degree, because you
also list an M.A. degree a year later?
00:27:00DEWAR: I did. It always confuses people. I always do that deliberately.
[laughter] The point is that the M.A. degree is the official senior degree in
Oxford which gives a right to vote in Convocation, the body which officially
controls Oxford and in which every past graduate has a right to vote in if they
have an M.A. degree. To get an M.A. degree, all you have to do is get a
bachelor's degree of some kind, and then seven years from the time you entered
the university, you apply for an M.A., which you then get automatically. The
M.A. ranks higher than the D.Phil., because the D.Phil. does not give you voting
rights in the university.
BOHNING: Were these war-related projects under Robinson's direction?
00:28:00DEWAR: Yes. They first started off with Freddie King, then later with Robinson.
BOHNING: Your first paper is on yohimbine.
DEWAR: That was what I was going to study for my bachelor's degree research.
There was a sequel to that, because I thought the established structure was
wrong on the basis of a sort of biosynthetic scheme I had for it. I got an ounce
of yohimbine hydrochloride with the idea of degrading it, although I never
actually did any work on it. The one experiment I did and reported, if I had
interpreted it properly, would in fact have established the structure. I got a
00:29:00compound which had been made before and was thought to be yohimbol. Yohimbine is
an alcohol carboxylic acid and yohimbol the alcohol. Decarboxylation of
yohimbine had been stated to give yohimbol. This is just decarboxylated. The
analysis, however, fitted better for the corresponding ketone. I just assumed
that the earlier formulation as an alcohol was correct. The fact that the ketone
was formed during the reaction showed that the carboxyl group had to be next to
the alcohol, which established that the accepted structure wasn't correct.
Yohimbine was supposedly used by the West African natives as an aphrodisiac.
00:30:00Several of us decided we ought to try this one night, so four or five of us
organized a yohimbine party. These included a girl in my year who was very
attractive and volunteered to come along. We ended up taking three times the
maximum recommended dose of yohimbine, and all we could say was that the results
were totally negative. I think this girl was rather disappointed. [laughter]
[END OF TAPE, SIDE 1]
BOHNING: Was that the end of your work on yohimbine, then?
DEWAR: That was the end, yes. [laughter]
BOHNING: That's an experiment that wasn't in the literature?
DEWAR: That's not been reported. [laughter]
BOHNING: You also had a paper with [Sir John] Cornforth on the santonin controversy.
00:31:00DEWAR: Yes. I worked with Cornforth in the same lab for years at Oxford, after I
finished my D.Phil. It's an amusing story. An Indian had reported the synthesis
of santonin in which one of the steps involved the reaction of a ketone with
ethyl formate to form a formyl derivative. Although the starting material was
inactive, the material he got was said to be optically active. Clearly what
happened was that his professor there was not very bright and said, "That's a
very interesting result. You must try it on a model compound." So he tried it on
cyclohexanone and, sure enough, claimed he got an optically active product. This
00:32:00was obviously nonsense. Cornforth and I repeated this work, and duly showed that
the product was totally inactive. That paper is one of the best examples of
editorial revision I've come across. We congratulated the author at having
achieved a result which could only be expected to occur once in ten to the power
of twenty all to the power of twenty trials. The editor didn't like this, so he
changed it to say, "This result would violate no laws of physics and would
indeed be expected to occur in ten to the power of ten to the power of twenty
trials," which if you work it out, is a lot different. He changed our estimate
by about one hundred orders of magnitude. [laughter]
00:33:00BOHNING: I was interested in that because so many of your papers, I don't want
to say attack, but certainly go after the establishment and show that things are
not what people are saying, that you have a different view. That tends to show
throughout many of your papers in later years. Do you have a particular penchant
for doing that kind of thing?
DEWAR: No, it's just that I've never had any respect for authority as such. All
my work has always been designed to answer specific questions. These usually
arose from things in the literature, where I didn't believe the explanation
00:34:00given, and this roused me to do something about it.
BOHNING: You were starting to get into some theoretical work at this point, when
the war was over. You looked at the mechanisms of the benzidine and Beckmann rearrangements.
BOHNING: Up to this point, most of your work was laboratory work.
DEWAR: The point was that during the war I couldn't work on my own problems;
this got me interested in theoretical chemistry, because that was something I
could do on the side. As a result of that, the first thing I came up with was
00:35:00the structure of stipitatic acid, which I deduced must contain a new kind of
aromatic ring. That was the start of nonbenzenoid
aromatic chemistry; it was the first case of a nonbenzenoid hydrocarbon system.
I knew so little about theory then, that I interpreted it wrongly in terms of
resonance theory. I didn't realize that this was actually Hacker s C7 aromatic
system. I also pointed out that the same was true for coichicine, because
alkaloids were the thing I was really passionately interested in and was
planning to work on if it hadn't been for the war.
BOHNING: Why did alkaloids attract your attention?
DEWAR: That was the big exciting area of natural product chemistry at the time.
All the natural product activity concerned alkaloids. I suppose this was because
00:36:00the methods then available for finding structures worked particularly well for
alkaloids. In order to determine the structure of a molecule by degradation, you
need a specific point to attack, and nitrogen atoms provide such points.
Compounds with only carbon, hydrogen, and oxygen were much harder to deal with.
BOHNING: Where did the theoretical aspect originate?
DEWAR: This happened after the war. At that time, theoretical organic chemistry
was a general term which included experimental studies of mechanisms. It
included everything except the synthesis. It has now become restricted to
00:37:00applications of quantum theory, but at that time it applied to everything. The
other things I'd become interested in were the benzidine rearrangement and pi
complexes. When I got to work on my own at the end of the war, the first thing I
did was some work on the benzidine arrangement in hope of finding evidence for
the pi complex theory. What got me interested in
theory as such was being asked by the Oxford University Press after the war to
write a book on theoretical organic chemistry. When I
started on it, I realized I didn't know any quantum theory and I didn't really
know much physical chemistry.
That was responsible for my move. At that point, I was offered a job as a
00:38:00physical chemist by Courtaulds in a new laboratory they were setting up to do
fundamental research. The reason for that was amusing. They had already
appointed the heads of the two sections, organic and physical, and they didn't
think I would be willing to work under the head of the organic section. But
perhaps I might be willing to work under the head of the physical chemical
section, given that I wasn't a physical chemist. So that's how I got onto it. It
seemed a wonderful way to learn about physical chemistry; being paid to do it!
BOHNING: Why did Oxford approach you to write that book very early on? You had
done some work in the area, but was it enough to warrant a book?
00:39:00DEWAR: The stipitatic acid paper really created quite a sensation, because it
was a problem which every organic chemist in the world at the time had looked
at, including Robinson and [Robert B.] Woodward, and none of them had come up
with a solution. So my paper really created a big stir. The pi complex theory
not so much, but it also aroused a good deal of interest. So I had got quite
well known for the work I had done on the side.
BOHNING: You mentioned Woodward. I'm also interested in the whole Ingold and
DEWAR: Woodward I didn't get to know until a lot later. There was a great feud
00:40:00between Ingold and Robinson. Quite frankly, I was totally on Robinson's side on
this. I never really had much of an opinion of Ingold. I think he's one of the
most overrated chemists there have been, and he was also a rather obnoxious
person. I had too many bad experiences later on with him, personally. One of the
worst was a case where a Fellow at QMC--Queen Mary College--now Queen Mary and
Westfield College--Ralph Hudson, had written some papers which were really good
and original. He sent them to the Journal of the Chemical Society, JCS, and
Ingold reviewed them and said they were absolute garbage. Hudson, who was a bit
00:41:00of a nervous type, came to me and said, "What should I do? Should I just forget
about it?" I said, "Certainly not." They were badly written, so I helped him
rewrite them and I also concocted a letter for him to send with them. This
happened when I was in bed with the flu, with a high temperature, which made me
angrier. I was really outraged by the whole affair. Since the paper criticized
views that Ingold held, he was determined to stop it from being published. I had
one or two other cases like that with other people.
The trouble with Ingold was that he got a second class degree at Oxford. An
idiosyncracy of the British system, which seems strange to everyone else, is
00:42:00that the Class of the Honors Degree one gets, the Class one gets in one's
bachelor's degree, was really vital. It labeled one for life, like a permanent
tattoo. When I went to Queen Mary College, I was trying to build the place up,
and I would not have dared to hire anyone who hadn't got First Class Honors,
however good they were, or people would say, "That can't be much of a place if
they're hiring people with Seconds." As I said, Ingold did get a Second, which
was probably richly deserved, and he spent the rest of his life trying to
persuade himself that he was the greatest chemist in the world, possibly of all
time, to make up.
BOHNING: Can you say anymore about the Ingold/Robinson controversy?
00:43:00DEWAR: It began when Ingold stole a lot of basic ideas from Robinson; I think
there's no question about that. Robinson was the type who was easily aroused at
such situations and never forgave him.
BOHNING: I'd like to go back to your move from Oxford to Courtaulds. How did
they get in touch with you and why did they want you to come there?
DEWAR: Courtaulds was forced to sell all their American holdings during the war.
Before lend-lease, America forced Britain to sell absolutely everything they had
in America at knockdown prices to pay for arms. It was only after they'd
00:44:00stripped Britain that they started lend-lease. One of the casualties was
Courtaulds, which would otherwise now own British Celanese down in Corpus
Christi. They got what seemed an awful lot of money at the time; I think it was
forty or fifty million pounds. The board of Courtaulds had nothing to do during
the war. They would sort of sit around eating large meals and drink wine and
decide what they'd do with this nest egg after the war. Remember, it was just
after Wallace H. Carothers had come up with nylon, so they decided to set up a
vast fundamental research laboratory where things like nylon would appear once a
week. The laboratory was not on quite the scale they'd originally planned,
because the pot had decreased in value by the time the war was over, but they
00:45:00hired a whole lot of people, turned them loose and said, "Do fundamental research."
BOHNING: You had several papers with [C. H.] Bamford.
Was he the head of the physical chemistry section?
DEWAR: Yes. We worked together nearly all the time I was there.
BOHNING: Who was head of organic?
DEWAR: Percival Moggridge. He died in the first year, or the first few months.
He just dropped dead one day in the lab--heart attack, with no warning at all.
They didn't replace him, so the whole place never really got off the ground as
it was expected to do.
BOHNING: Some of the things you and Bamford did together dealt with
polymerization. Was this one of his areas of interest?
DEWAR: No, it wasn't, but we had more or less agreed to work on things which
00:46:00might be of use to Courtaulds. Polymerization was one of
them. Another was the process to form acetic
anhydride by pyrolysis of acetic acid to form ketene, then reacting that with
acetic acid. So we had a paper on the thermal decomposition of acetic acid in
the gas phase. We also did quite a lot of work on the
tendering of fabrics. If you dye fabrics with certain dyes and expose them to
light, they disintegrate. Nothing really was known about that, except that it
was thought to be some kind of oxidation. We worked out the mechanism of that in
BOHNING: How many other people were in your group?
DEWAR: There were about five or six altogether in that group.
00:47:00BOHNING: Is that where your interest in color came about, when you started
working on dyes at that point?
DEWAR: Yes, it was. It also solved my problem about learning physical chemistry.
I taught myself quantum mechanics just by reading about it; I've always been a
bit unorthodox. I also chose a most unsuitable book, the one by Eyring, Walter,
00:48:00BOHNING: Yes, I know the book.
DEWAR: I found it very hard. I thought it was just a sign of my stupidity. [laughter]
BOHNING: I don't think you're the only one that's found it hard. [laughter]
DEWAR: Yes, it's a rough one.
BOHNING: But that was about all that was available at that time. There wasn't
much else available, was there?
DEWAR: No, there wasn't.
BOHNING: In 1947 you had a paper, "An Interpretation of Light and Its Bearing on Cosmology"
BOHNING: I have a copy of it here. I was intrigued by it.
DEWAR: Oh, you do? I'd like a reprint; I've lost it.
BOHNING: Well, I can give it to you in a moment.
00:49:00DEWAR: Thanks very much. Somewhere I've probably got some reprints of it still,
but I don't know where they are and I never include it in my list of
BOHNING: Why did you write that paper? Here you are working doing fundamental
research and you publish something like this.
DEWAR: I have always been interested in astronomy; I got interested in it, among
many other things, from articles in the Children's Encyclopedia. That,
incidentally, was a wonderful work. It's a shame that it hasn't survived, but
television would in any case have killed it. Anyway, when I was about twelve, I
00:50:00used a Christmas present to buy a book called The Splendour of the
Heavens. It was an enormous volume, reviewing
astronomy as it was at the time, 1925, with chapters written by leading
astronomers and full of photographs. It was a very good book. This got me really
interested and I've kept an interest in astronomy ever since, up to a sort of
One day I had an idea of a possible alternative to general relativity. The idea
was to keep special relativity, but regard it as indicating an actual physical
change that occurs in things which are moving relative to a local framework,
light traveling with velocity c relative to that framework. To work this thing
00:51:00out, I went hunting around the library and found an old paper in which someone
had proved that all the experimental phenomena that follow from general
relativity can be explained in this way. I even found some evidence for this idea.
I did this for fun. I mentioned it one day to Sir David Ross, who was the
provost of Oriel College. He's a cousin of my father's and an Aristotelian
philosopher. He was highly delighted, because he had never liked relativity
theory anyway. So he got me an introduction to Milne, who was then one of
leading theoretical astronomers in the world. I spent a whole afternoon talking
00:52:00to him about this. Milne got more and more agitated. He kept raising new
objections, but I was able to meet all of them. Finally he said, "Well, it's
obviously nonsense. Anyone can see it's nonsense. But I can't see why it's
nonsense. So you must publish it, and let someone else find out what's wrong
So with his help, my paper duly appeared in Philosophical Magazine. [laughter]
I've kept working on it since. The original form was naive, but there's a
version which I think does explain everything, and in fact it fits in nicely
with the continuous creation of matter. It also accounts for the background
radiation. But I've certainly no intention of trying to publish it.
BOHNING: What kind of reaction did you get when it appeared?
00:53:00DEWAR: It was totally ignored. I had one request for a reprint. [laughter]
BOHNING: At this point, you also started publishing some papers on resonance
energies which were probably more theoretical than anything else you'd done up
until that point.
DEWAR: Yes, they involved just simple Huckel calculations.
BOHNING: When did you first learn of the Huckel method?
DEWAR: I read about it. Then I started doing calculations myself. At the time,
one did everything by hand, which was really quite a business, solving secular
equations without calculators.
00:54:00BOHNING: Yes, I can imagine. Not even mechanical calculators?
DEWAR: No, no.
BOHNING: I remember in the 1950s seeing a room full of theoretical people with
DEWAR: Yes. [laughter]
BOHNING: This is about the time that book came out, in 1949. What kind of
reaction did you have to that book?
DEWAR: The book in fact created quite a sensation. It was late, actually. It
took three years to appear, because at that time, after the war, everything was
a mess. But it had a whole lot of reviews, each worse than the last, and each
00:55:00time another review appeared the sales went up. It was read by a whole
generation of young organic chemists, and it was the thing which really
converted organic chemists to molecular orbital theory. It was the first account
of organic chemistry in terms of molecular orbital theory.
BOHNING: Had you had any contact with people in the States, such as [Saul]
Winstein and other physical organic chemists?
DEWAR: No, none at all. I had not met any of them.
BOHNING: That's interesting.
DEWAR: In fact, I'd hardly met any of the theoreticians in Britain, either. The
only one I met was [Charles A.] Coulson.
BOHNING: Later on you had a paper or so with Coulson
and also with [H. Christopher] Longuet-Higgins.
00:56:00DEWAR: I knew Christopher well; he's one of my oldest friends. We were in school
at Winchester together.
BOHNING: So your association goes back that far?
BOHNING: Could you tell me something about Coulson and Longuet-Higgins from a
DEWAR: The first time I got to know Coulson was when I wrote a rather naive
paper describing calculations for pi complexes using Huckel
theory. Coulson came up with a paper, which he sent
to me before publishing, blasting it and saying it was total nonsense. Being
reasonably ingenious, I was able to persuade him that it wasn't nonsense, but at
the same time it wasn't sense either; you really couldn't tell. But it certainly
00:57:00wasn't too meaningful. So we published a joint paper pointing out all the
potential errors in using Huckel theory for ions, and this appeared next to my paper.
There is an amusing sequel to this. I talked about this idea of pi complexes at
a meeting in Montpellier in 1950, and Winstein was present. This was just when
Saul had come up with his evidence for the norbornyl cation being nonclassical.
Saul was outraged. Mary and I knew them, both Saul and his wife Sylvia, well.
She told us one day that when Saul proposed to her he had said, "I'm never going
00:58:00to get anywhere. I'm really not good and I'm never going to be more than a
second-rate university professor at some minor university." Quite frankly, I
think that was a good assessment. Saul really didn't have original ideas. He was
extremely painstaking and he got into the area just at the right time and he did
extremely good work in it. But he did virtually nothing that was really
original. The one exception was discovering this nonclassical ion. So at these
lectures he was really outraged. He never did admit that I had any part in it at
all. In fact, the climax came when he published a paper with [M.] Simonetta on
00:59:00one of these nonclassical ions without any reference to the calculations I had
done and also without reference to my paper with Coulson in which we had shown
that such calculations are totally meaningless. I
think that was unfortunate. He didn't need to do that. It also did harm because
these ions are best regarded as pi complexes. If you look at them that way, a
lot of the things about them become immediately obvious.
[END OF TAPE, SIDE 2]
BOHNING: What about Jack Roberts? Didn't he have a little paperback on molecular
orbital calculations around that time?
01:00:00DEWAR: Yes. Jack first visited us after I went to London to Queen Mary College.
After that, he used to visit us regularly when he came over and I've known him
very well ever since.
BOHNING: What was your reaction to his book, given what you'd been doing?
DEWAR: My memory is that it was fine at that time. You couldn't do a lot, but
it's a good account of what sort of things you could do then and how to do them.
BOHNING: While you were at Courtalds, you published a number of theoretical
papers. There were still practical papers coming out, but at the same time there
were a number of theoretical papers developing.
01:01:00DEWAR: Not many at the time. There was the original one on pi complexes, the one
on resonance, and I think that was all except for the
paper from the Montpellier conference, which appeared in Bulletin de la Sociëte
Chimique de France in 1951. That's the one where I
suggested the pi complex structure for the metal complexes.
BOHNING: In 1950 you had the paper on tropolone, and
in 1952 you started that series on the molecular orbital theory of organic chemistry.
01:02:00DEWAR: When was tropolone?
BOHNING: In 1950.
01:03:00DEWAR: I'd forgotten it was so late. Yes, it would be 1950, of course. Yes. I'm
getting a bit mixed up with the timing of this, I must confess. The point is
that I introduced the tropolone idea when I was at Oxford. What triggered it off
01:04:00was one of the meetings we used to have regularly about penicillin, when people
visited from America. This was early on, when no one knew what the structure of
penicillin was. It didn't seem to fit any possible formula. One of the people
visiting happened to remark that penicillin seemed to be like stipitatic acid, a
compound for which you couldn't write a rational structure. So at the end of the
meeting I went off to the library and looked at Raistrick's papers and came up
with the solution. That was why it happened while I was in Oxford. My paper,
however, didn't appear until 1950, and I can't remember what happened in between.
01:05:00BURNING: How did you make the connection with QMC, Queen Mary College, when you
moved there in 1951?
DEWAR: When I went to Courtaulds I didn't really mean to stay there more than
two or three years. But there were absolutely no jobs going in England at the
time. The one exception was the chair of color chemistry in Leeds, which I
nearly got. I was second. But it was really good fortune for me that I didn't,
because it would have been another dead end. [laughter] Then, two things came up
01:06:00at the same time. One was a chair at the Manchester College of Technology--not
the University, which is different--while the other was the appointment at QMC.
I don't know how QMC got onto me or what happened, because it was really a very
extraordinary appointment. I got this offer while I was in America, the first
time I'd been there. I had been asked to give the Reilly lectures at Notre Dame.
I was there for about two months altogether. I got this offer out of the blue
while I was there, not even an interview or anything. I was the youngest person
ever to be appointed to a chair in any part of London University, so it was
really very odd. I heard later that what had happened at the meeting was that
01:07:00someone said, "It's time that something exciting happened at QMC." QMC was then
very much a poor relation of the University of London, in the east end of
London, the poor part. They said, "Let's get Dewar. He will stir the place up!" [laughter]
BOHNING: What was QMC like when you went there?
DEWAR: Oh, it was dreadful. The Chemistry Department was a huge, brick building
with five floors and no elevator. It looked as though it had been built as an
institution for housing poor people. It was in a terrible condition, there was
no equipment at all, and there was no money to buy any. It was just a shambles
01:08:00when I went there. The place had been ransacked during the War, when the
University was deserted. My predecessor was Partington. Do you know Partington?
BOHNING: Oh, sure! J. R. Partington.
DEWAR: He did nothing about it at all. He made no attempt to get money or do
anything with the place. So it really was in an incredible condition.
BOHNING: What kind of students did it attract?
DEWAR: We got very good students, because we only took one in twelve of those
who applied and all those who applied were qualified for admission to the
University of London. London was next after Oxford and Cambridge on everyone's
priority list. There were a huge number of people applying.
01:09:00BOHNING: What were your goals outside of stirring things up? Were you going to
build the Department?
DEWAR: My object was to make it the top Chemistry Department in the University.
By the time I left, we had got to the point where people were putting us down as
first choice, ahead of Imperial College or University College. We really got the
place going. That was in spite of our dreadful building. When I went there I was
promised a new building in between five and seven years. They were building a
new engineering block, and we were going to be next. But when chemistry started
doing so well, they decided to give the new building to physics instead, in hope
that it would help physics become better too. That was one of the things that
made me leave. It was just the last straw.
01:10:00But I built the Department up. The first year there wasn't even glassware with
ground joints or anything, so I ordered a whole lot of equipment. The laboratory
steward who'd been under Partington was horrified. He said, "But, sir, we
haven't got the money." I said, "It doesn't matter; we need the stuff" At the
end of the year we'd overspent our budget by one hundred percent. The budget was
the equivalent of seven thousand dollars for everything--the teaching, the
research, all the chemicals and so on. Maybe it was seven thousand pounds.
Anyway, whatever it was, it was ridiculous. The College was horrified because
01:11:00nothing like this had ever happened in its whole history.
The laboratory steward was a financial genius. He should really have been on the
Stock Exchange. I rapidly corrupted him. I said, "The situation here is
ridiculous. We must overspend every year by one hundred percent. No more than
that, because that would be unreasonable and we don't want to be unreasonable."
He agreed. Every year for five years we overspent our budget by exactly one
hundred percent, and each year the college doubled my budget. They did
everything they could to stop us from overspending. They had a whole group of
people scanning our acounts. However, every time, when the smoke had cleared,
we'd overspent the budget by exactly one hundred percent. After five years, when
our budget had increased by a factor of two to the fifth, i.e. thirty-two times,
it was finally acceptable. So I then used the situation to bring off another coup.
I had been trying to get QMC to appoint a second professor, because one of my
01:12:00problems was that the two senior people in the place hadn't spoken to each other
for five years when I went there, and they wouldn't even sit in the same room
together. It was just intolerable. I couldn't delegate anything to either of
them without the other being up in arms. If I tried to delegate anything to
anyone else, then they both came screaming at me. So I had been trying to get a
second professor to insulate myself from them, and the college refused. They
said they had no money. After five years, at lunch one day I was talking to the
principal of the College. I put the idea into his mind in such a way that he
thought it was his. He suddenly turned to me and said, "Why don't we appoint a
second professor? You have all these problems with the budget and everything,
you could turn it all over to him." I said, "Oh, what a wonderful idea." So we
01:13:00appointed Keble Sykes. I got an invitation to go to Yale for the semester, so I
went off to Yale, leaving Keble in charge. The first faculty meeting he had
after I left, Jones and [Wilfred John] Hickinbottom came to blows and had to be
separated. They were both over sixty. [laughter]
BOHNING: I didn't realize Hickinbottom was there. I remember his book.
DEWAR: It was a very original book. It was excellent; very good indeed.
BOHNING: It's a very unusual approach, but I used it many times in graduate
school. I still have my copy.
DEWAR: I have too; it's around somewhere.
01:14:00BOHNING: You produced an awful lot of work during that period at QMC.
DEWAR: We did. We got a lot done.
BOHNING: It's really quite amazing.
DEWAR: It was basically controlled by what we could do, because we had so little
equipment. I'd been there six years before we got even an infrared spectrometer.
We were really lucky.
BOHNING: Shortly before you went there, you gave the Reilly lectures at Notre
01:15:00Dame in 1951. Did that series of papers that began the molecular orbital theory
of organic chemistry come out of those Reilly lectures?
DEWAR: Oh, yes. What happened was that Christopher Longuet-Higgins and Charles
Coulson had developed the idea of using perturbation theory in organic chemistry
on the grounds that this should be the best way to calculate the small
differences in energy on which chemical reactivity depends. However, they missed
the essential point that made the whole thing work. I hit on this when I was
01:16:00preparing my lectures for Notre Dame, so that's what set the whole thing off.
BOHNING: What kind of reaction did you get to that initial series that all
occurred together in the Journal?
DEWAR: I'd been told that you had to keep papers very short in JACS [Journal of
the American Chemical Society], so I wrote them very concisely. The referees
agreed that the material in them was all nonsense and that the author must be
mentally defective. At the same time, they said the papers should be published,
but should be shortened by twenty-five percent. So by the time they were
shortened, they were totally unreadable. [laughter] I discovered later that JACS
at that time had a policy of not publishing any theoretical papers whatsoever.
01:17:00This had started a few years before, for some reason or other. They not only
published my papers, but also rescinded the ban because of them.
BOHNING: That's interesting. I think later on when you had the second book,
twenty-five years after the first one, you commented in the introduction that
that set of papers was indigestible.
DEWAR: They were. They were terribly difficult. [laughter] That was because they
were already very condensed and then I had to shorten them.
BOHNING: Was that your first time in the United States?
DEWAR: Yes, it was.
BOHNING: Were you in touch with other people in the States at this point?
Earlier you said you had no contact with physical organic chemists in the United States.
DEWAR: Hardly at all. There were just one or two who visited in London, but
01:18:00very, very few. No, that visit was when I got to know American chemists. I
traveled around a lot and saw a lot of them.
BOHNING: Anyone in particular?
DEWAR: One of them in particular was [Norman] Kharasch. We corresponded
regularly after that.
BOHNING: What was his reaction to those lectures?
DEWAR: Oh, he didn't know anything about it.
BOHNING: I see. He was from a different era.
BOHNING: But did he encourage you to continue this approach?
DEWAR: No, because it really wasn't anything to do with him at all. He was
01:19:00interested in polymers and free radical reactions. He was one of the people who
reviewed my book. He was very conservative and rather meticulous. When I first
met him, he apologized for his review. I said, "No need for apologies; your
review it increased the sales greatly!" [laughter]
BOHNING: Around that time, you also had another paper on the correspondence
between resonance and molecular orbital theories.
DEWAR: With Longuet-Higgins.
BOHNING: You really criticized the old Resonance Theory.
DEWAR: Resonance Theory doesn't follow from Valence Bond Theory as is usually
01:20:00assumed. In fact it has no real basis. The only reason why it works is the
almost accidental correspondence which Christopher and I pointed out.
BOHNING: Yes, I found that very intriguing.
DEWAR: It's my own fault, you know. It's a shame, because that theory is still
by far the best qualitative approach there is to organic chemistry, and it's
never been picked up. It has remained totally unknown because I never wrote a
book about it. One of the bad things I inherited from Robinson was the feeling
that one shouldn't publish papers unless one has to. Having put all this in
print, I thought it would be wrong to do anything more. But I should have
written a book about it, and that was very foolish. I probably would have, but
this was when I moved to QMC, and as I've already said, I had a hell of a time
01:21:00there, struggling to start research in a place with no money or equipment or
anything, and with Jones and Hickinbottom to contend with as well. I nearly had
a nervous breakdown the first year I was there. After that I pulled myself
together and didn't let it get me down again. But it was very rough. I really
hadn't time to even think about writing a book. But it's a shame, because if I
had, the book I produced with Ralph Dougherty would have provided me with a
BOHNING: But you made the comment in the second book--the molecular orbital
book--that organic chemists in general were still quite ignorant of molecular
01:22:00orbital theory, and that those who didn't pay attention to it were doomed to
solving minor problems.
DEWAR: I'd forgotten that. [laughter] Yes, they were.
BOHNING: I don't know if you used the word doomed, but it was similar to that.
You were really quite a disciple of molecular orbital theory and its approach to
DEWAR: Yes. I got devoted to it early on. It goes back to developing what I
christened the PMO theory in my lectures at Notre Dame.
BOHNING: I'm still curious as to the resistance you may have met in introducing
01:23:00extensive theoretical work in what was traditionally organic synthesis, a lot of
basic organic chemistry. Was there much there much resistance to that, or could
you convert people?
DEWAR: In what sense?
BURNING: In terms of their using MO theory. Perhaps I'm putting too many things
together. You did a lot of theoretical work, but later you also did a
significant amount of experimental work, which brings the two together.
DEWAR: All my work, or nearly all of it, was experimental until quite late on.
It was only relatively recently that I took to theory in such a big way. Twenty
years ago, most of my published work was still experimental.
01:24:00BOHNING: We haven't even touched on the heterocycles and a lot of other areas
yet, but I guess what I'm after is the change that was occurring in this time
period in the early 1950s. Physical organic chemistry was really becoming one of
the biggest things. How were people reacting to the kinds of things you were
doing? You said Kharasch didn't know anything about it.
DEWAR: No, he didn't, nor did anyone else. If I'd written a book about it, I
think I could have converted them. The book I wrote got people interested in
molecular orbital theory, but it remained very qualitative.
BOHNING: Do you think things were different here in the States than they were in
England in that respect?
DEWAR: I don't think so. I think they were very much the same. Teaching was
still done entirely in terms of Resonance Theory. For a long time there were no
01:25:00textbooks dealing with molecular orbital theory.
BOHNING: Unless you wanted to wade through Eyring, Walter and Kimball as a start!
DEWAR: I wasn't thinking so much of quantum theory in the technical sense, but
just introducing students to the idea of orbitals.
BOHNING: How did you do this at QMC?
DEWAR: I just taught one course there which appeared in the form of a paperback
book. At that time in Britain, the school courses went up to quite a high level
and were taught in the same sort of way that they would have been in a
university. However, there was nothing in them about modern atomic theory. What
01:26:00I did in my course was to fill in this gap. In this one term I gave a complete
account of modern ideas in chemistry, starting with atomic structure, wave
mechanics, orbital theory, thermodynamics, statistical mechanics, reaction
kinetics, the whole lot. It was great fun and my people enjoyed it. It also
acted as an intelligence test, because people who did well in my course always
did well in their final degrees, while the ones who failed, failed.
BOHNING: It certainly takes a more rigorous intellectual approach to things, by
going through quantum theory.
DEWAR: Yes, but I don't think you need to go through it mathematically. You
01:27:00really don't need that. You can teach orbital theory very well in qualitative
terms. Then you can go on to perturbation theory without having to solve
equations or anything. I think this is really the way to go. That's why I think
it's such a shame that this approach--and it's my fault entirely--has never been
adopted. It took about twenty-five years for a book to appear on it, the one I
wrote with Ralph Dougherty. Hardly anything needed to be added to bring it
totally up to date. The only really new idea was the concept of anti-Huckel
aromatic systems, which is needed to treat pericyclic reactions. So an almost
01:28:00identical book could have been written back in the 1950s. I think if it had
been, the results would have been very dramatic. When it did appear, most of the
references in it were to papers published more than twenty years previously, so
people assumed it couldn't be any good. What I should have done was call it
something different, presenting the ideas in it as something entirely new, with
no references to the literature at all. A lot of people have done that to my
published papers, so I should have done it to my own. [laughter]
01:29:00BOHNING: Very early on at QMC, you had a symposium on molecular rearrangements.
Winstein was there, and others. There's a review of that in the literature.
DEWAR: At QMC?
BURNING: In 1954.
DEWAR: Did I? I don't recall that at all.
[END OF TAPE, SIDE 3]
BOHNING: This paper summarizes the conference.
DEWAR: Oh, it comes back now. I'd quite forgotten it.
BOHNING: You had a pretty good lineup of people, and I was wondering what
01:30:00brought this about and what the results were.
DEWAR: My memory is totally blank on that. I really can't remember anything
about it now.
BOHNING: Winstein was the only one that was from the States, from what I can see.
BOHNING: Even Hickinbottom was there.
DEWAR: He was a local, yes.
BOHNING: I just wondered, because holding that symposium would be part of your
building up the department.
DEWAR: I really am upset at forgetting about it.
01:31:00BOHNING: You also did some work on liquid crystals at that
time. How did you get into that area?
DEWAR: When I went to Courtaulds, I started thinking up things to do with
polymers, which I knew absolutely nothing about at all. It occurred to me that
if you use a liquid crystal as a solvent, it might speed up polymerization by
lining the molecules up so that they join up end to end more easily. We tried
this, but the results were negative. However, the idea of using liquid crystals
as solvents remained in my mind and at QMC it occurred to me one day that
molecules dissolved in a liquid crystal might be aligned, something that could
01:32:00be checked by spectroscopy, using polarized light.
Since I had an Indian who wanted to be given a problem, I put him onto studying
binary systems of pairs of liquid crystals, to see under what conditions one
could get a mixed liquid crystal as a first step to studying solutions in liquid
crystals. We published two papers reporting our results. However, I never did
01:33:00any more because I couldn't get any students interested in the problem. Being
the Professor, I could, of course, tell anyone to do anything, having total
power; but I never liked doing that. I've always liked giving students a choice
of projects. The trouble with liquid crystals was that the students would ask me
where they could go and read up about the problem. I'd say, "Well, no one's done
any work on this at all; it's entirely new." When I said that, they'd
immediately conclude that something must be wrong with it. So it was a long time
before I could get anyone to do any work with liquid crystals again.
BOHNING: What level were the students at Queen Mary who were doing research with
you? Would that be the B.A. level?
01:34:00DEWAR: They were all working for D.Phil.s, the Ph.D. level. I only had one
postdoctoral fellow, and that was Roland--Roly--Pettit. That was because he got
an 1851 Exhibition. These came from the big World Fair in Britain in 1851, which
made a profit unlike any similar function since. Those in charge used the money
to found a scholarship scheme to bring people back to England to study. Pettit
already had a Ph.D. in Australia, but he was sent over officially to study for a
Ph.D. with me. Apart from him, I never had any postdocs.
BOHNING: During that time you were at Queen Mary, about how many students did
01:35:00you have? You were there for eight years, something like that.
DEWAR: I've got this all on record, but I think it must have been about twenty.
BOHNING: Twenty in eight years--given the conditions under which you were
working, that's amazing.
DEWAR: Yes. They were all in one great big lab. It was all I had.
BOHNING: Were the students working with other people?
DEWAR: Yes. I think the total number in the department was about fifty.
BOHNING: That's a very good number. Also during this period you had a series of
papers that seems out of place. It was something called "Promoters for the
Dropwise Condensation of Steam."
01:36:00DEWAR: Right. The faculty at QMC used to have lunch together in the college
dining room, so one met people from other departments. One day at lunch, one of
the engineers got talking to me about the problem of dropwise condensation. The
trouble with condensers is that the water normally condenses in a film. Now
water is a very bad conductor of heat, so the rate at which steam condenses is
limited by the rate at which heat is conducted through the film of water. If the
surface were water-repellent, so that the water condensed in drops, it would
condense up to twenty times faster. My colleague asked me if I thought there was
any way one could coat the surface of a condenser to make steam condense in
01:37:00drops. I said I thought that could be done quite easily. Then he asked if I
would work on it. I said, "Only if you find me money to do it." So he rushed off
and duly found a source of money from somewhere or other.
In the meantime, I had a student who needed some source of support because he
should have had a First class degree and only got a Second. It was almost
impossible for people who didn't get Firsts to get any support in Britain from
the government. So I put him onto this, and this was how it started. I assumed
01:38:00that a lot must be known about it already, and people must have tried the
obvious thing, which was to attach water-repellent molecules to the surfaces. It
turned out that no sensible work had been done on it because it had all been
done by engineers who knew no chemistry. Our original idea was to try a number
of simple molecules and find which was the best. Since condensers are made of
copper, which has a high affinity for sulfur and selenium, and since
hydrocarbons are water repellant, what one needed was a long chain hydrocarbon
with an anchoring group containing sulfur or selenium. The student made about
eighty such compounds, with various groups containing sulfur or selenium.
Anytime one of them got on the surface, it never came off again. So in that
01:39:00sense, the project was a total failure. Everything was one hundred percent efficient!
We tried one of them in the condenser of a ferry boat going across the English
Channel. We drove down to Southampton. The first time we went there, the
engineer was obviously horrified at having his ship and engines played around
with by ignorant amateurs. The student would climb inside a condenser while the
engineer stood there wringing his hands and saying, "Take care, take care."
[laughter] After that, we used to go down once a month, and the student would
climb inside the condenser with the portable steam generator. When he came out
saying steam was still condensing in drops, everyone cheered. At the end,
01:40:00everyone was quite pleased and realized that their ship was being used for an
important experiment. [laughter]
BOHNING: You also started the heteroaromatic work at this time. How did you get
into that area?
DEWAR: That happened because I had an Indian student who arrived to do a Ph.D.
When he arrived, he already had an M.A., and he said, "For my M.A. I worked with
compounds which were liquid. I would like, if possible, to continue working on
liquid compounds, because I have no experience with handling crystalline
materials." I was obviously in an inventive mood that day, as I said, "Oh, in
that case you will make these boron compounds!" [laughter] This was an idea I'd
thought about vaguely before. He said to me, "But will they be liquid?" I said,
01:41:00"Who can tell? No one has ever made any of them." So the official purpose of his
work was to synthesize new liquid heteroaromatic compounds. One of the compounds
he made did in fact turn out to be liquid! But that's how it all started.
BOHNING: Did you have theoretical interests in those compounds at that time as well?
DEWAR: Not specifically, but obviously they were interesting in the sense that
they were isoelectronic with aromatic hydrocarbons. It was interesting to see
how stable they would be.
BOHNING: That work went on for a long time.
DEWAR: Yes it did. I got fed up with it in the end. It's surprising, actually,
that it hasn't been taken up by other people, given the interest aroused by any
new aromatic system. Here we have a whole new class of aromatic systems, and one
01:42:00could do similar things with elements other than boron and nitrogen.
BOHNING: The one thing that strikes me, even up to this point in the late 1950s,
is the diversity of the work that you did. I don't want to say you were jumping
around a lot, but there were always new areas that you were developing.
DEWAR: I've always had very wide interests. There are two other things about
this, too. I've always thought that graduate students should be given individual
problems, and not just bits of a major problem. One of the things I learned
01:43:00early on, after coming in contact with Collingwood, was his principle that the
purpose of any experiment should be to answer a specific question. That's how
I've always operated. The boron nitrogen work was an exception, where we were
studying just the specific properties of a whole class of compounds. So, a lot
of them were made for specific reasons. Otherwise, all my research has been
directly aimed at answering specific questions. So I usually published only one
or two papers on each topic because the work they reported was enough to answer
the question I wanted to know the answer to.
BOHNING: What kind of contact did you have with the Oxford and Cambridge people
01:44:00while you were at Queen Mary?
DEWAR: None at all.
BOHNING: None at all. That's interesting.
DEWAR: No, none at all. I'd occasionally go back and visit people at Balliol,
but chemically, not at all.
BOHNING: You had this molecular rearrangement symposium that we just saw. Did
you bring in other people? Did you have a seminar program in which students were
exposed to outside speakers?
DEWAR: No, we didn't. The only thing we had was an annual lecture for the
students, where we had someone visiting who gave a lecture.
01:45:00BOHNING: Then we get to hyperconjugation. I'm not sure whether that was still
developing in England or when you got to Chicago.
DEWAR: That was in England. I'm trying to think about the timing. I was dubious
about the whole concept of hyperconjugation. My idea was that one could account
01:46:00for everything in terms of changes in bonding with hybridization. Howard
Schmeising and I produced two papers. He did some
calculations with a very primitive computer, which were perhaps not too
meaningful, but we also came up with a very strong qualitative argument
supporting the idea. So that's what really got me going on it.
BOHNING: I noticed that in that one paper you acknowledged General Electric [GE]
for computational facilities.
DEWAR: Yes. This was a primitive computer using relays rather than vacuum tubes. [laughter]
BOHNING: Was this the first time you got into any kind of computer work?
DEWAR: Absolutely, yes.
BOHNING: I'm assuming you didn't have a computer at QMC, or did GE give you something?
01:47:00DEWAR: No, we didn't have anything. The student went over there to use it. I
can't remember how we first got in contact with them. I think he had in fact
been working there for the summer before he came to QMC.
BOHNING: You still didn't have any mechanical calculators at this point?
DEWAR: We did get a mechanical calculator.
BOHNING: So you were really working in some isolation. You had no contact with
Oxford and Cambridge, and you didn't have much contact with people in the States.
DEWAR: I was almost completely isolated.
BOHNING: That's interesting.
01:48:00DEWAR: I was really working entirely on my own on things I was interested in.
BOHNING: You've already said, in a number of cases up to this point, referees
said that it was nonsense, but it was still published. What kind of problems did
you have getting these papers published?
DEWAR: That wasn't a problem in those days. The JACS case was exceptional and,
as I said, this was at a time when JACS officially had a policy of not
publishing any theoretical papers at all. I didn't publish anything else there
for many years; all my work was published in Britain. Things were very different
then. Referees were really conscientious and didn't come up with hysterical
attacks on authors. In fact, the Chemical Society had a rule. Their instructions
01:49:00to referees were quite simple. They said the referees should confine themselves
to pointing out errors of fact or logic in a paper and that their opinions were
of no interest.
BOHNING: Ingold notwithstanding. Did he referee on any of your papers?
DEWAR: No, he never refereed any of my papers. At that time, you see, I was
doing very little kinetic work or anything like that. It was nearly all synthetic.
BOHNING: Then you moved to Chicago in 1959. You had met Kharasch earlier, but
how did that move come about? I've read that it was somewhat difficult in a way
to leave England.
01:50:00DEWAR: We thought an awful lot about it. It was Kharasch's chair that I was
offered there. It was a hard thing to decide, because my boys at that time were
fourteen and twelve, and we'd bankrupted ourselves sending them to private
schools in Britain, which were very expensive. We were really concerned about
them. We just wondered how it would affect them. We wanted to go because things
got really difficult in England in the sense that I still had this really
terrible building at QMC.
01:51:00I should, in fact, have got the chair at Oxford when Robinson left. Robinson was
a real autocrat in the place, partly because there was no one else there who was
any good. He had no way of bringing good people in, because the appointments
were all College appointments; there were virtually no university lectureships
or anything. The people teaching the university laboratories were Fellows of
colleges over which Robinson had no control. In fact, he only appointed one
01:52:00person who was a physical organic chemist. He was very well known in the 1950s
and did lots of early work in radical reactions. I can't remember his name right
now. It'll come back in a minute. But when he left, everyone in the department
wanted to have a nice quiet period with someone who wouldn't chase them around.
What they wanted was someone to stabilize the position that Robinson had
achieved in the department. I should have got that chair. Looking back, I'm glad
I didn't, because if I had I would have stayed in England. I don't think I would
have been too happy.
01:53:00BOHNING: What swayed you, then, to finally accept the offer at Chicago?
DEWAR: We talked about it for months. I remember one time in Madrid we turned
our kids out on a boat on the lake in El Retiro, the big park there, and they
rowed around for two or three hours while we just sat talking about it. But the
thing that finally settled things for us was the discovery that Chicago had a
wonderful school, the so-called Laboratory School, which at the time was really
quite unique. In it people could go at whatever pace they liked with no age
limits. You could be at different grades for each different subject. If you got
beyond the school level, you could even take courses at the university. That was
what really convinced us to go.
01:54:00From my own point of view, I was anxious to go. I couldn't get any work done in
London. For one thing, I was on six University Committees. To be on even one was
considered a great honor, but I've always hated committees. My feeling about
committees is that either the other members think the same way I do, in which
case it is a waste of my time attending meetings, or they disagree, in which
case it's a waste of my time arguing with a bunch of obstinate fools. I'm really
not a committee man. Furthermore, these Committees met at the Senate House, the
administrative center of the University of London, which was right in the middle
of London, and it was a hell of a job getting to and fro by car from QMC. I was
spending half my time just traveling around London by car, wrestling with
01:55:00The climax came when I was elected one of the Honorary Secretaries of the
Chemical Society. There were two, and it was a very prestigious appointment. But
as far as I was concerned this was the last straw, because the Chemical Society
was in yet a third place. I just couldn't get any work done at all. The only way
I could deal with the situation was by leaving the country. We had also got a
bit disenchanted with Britain. The class system disgusted us and the British
Labor government had made a shambles of the place. We didn't like it. The other
thing was that whenever we had British guests at our home in London for dinner
01:56:00parties, we'd have a terribly sticky time with our guests, wondering what we
should say and wondering if we had done anything wrong. Things were quite
different when we had American friends visiting. Then we had a really good time.
So we decided we were on the wrong side of the Atlantic.
BOHNING: But you hadn't really looked outside the country. They came to you, is
DEWAR: Yes. I hadn't looked at all.
BURNING: Once Robinson's chair at Oxford wasn't available, did you have any
other options in England, or did it look like until Chicago came through you
were going to stay at QMC?
DEWAR: I was offered the chair at Glasgow, which was a big one, but I didn't
have the slightest inclination to go from London to Glasgow. That wasn't any help.
BOHNING: What did you find when you came to Chicago? What was it like in the department?
01:57:00DEWAR: Oh, we had a wonderful time. We enjoyed Chicago very, very much.
BOHNING: Who was there in the department at the time?
DEWAR: [H. C.] Brown was the main organic chemist there. Henry Taube.
[END OF TAPE, SIDE 4]
DEWAR: We became very close friends with the Taubes. It's terrible, you know,
I've always been hopeless with names. I get worse with time.
BOHNING: Was [Harold] Urey there?
01:58:00DEWAR: Harold had left. He'd gone to La Jolla. Bill [Wilbert H.] Urry was
there--the organic chemist. Gerhard Klaus. [pause] It will come back, gradually.
01:59:00BOHNING: How would you compare your position in Chicago to the one you had just left?
DEWAR: Chicago was a joy; London had become a misery.
BOHNING: When you were in Chicago, you didn't have any more administrative responsibilities.
BOHNING: What were your teaching responsibilities?
02:00:00DEWAR: Hardly any. Indeed, one of the few faults of Chicago was that there were
so many faculty that it was quite difficult to get any teaching at all. You had
to fight. They were quite concerned at my coming at the thought of having
someone else competing for courses. So they invented one for me, which was an
introductory course in organic chemistry for nonmajors, which was full of premeds.
BOHNING: How did you find doing something like that?
DEWAR: I really enjoyed it.
BM-WING: That's interesting.
DEWAR: I have always enjoyed teaching very much, and I think elementary courses
are the most fun to teach, because there you don't have to put effort into
preparing them. It's just a challenge to get the stuff across to people. I
02:01:00always have enjoyed that. It's one of the things I really missed in Austin, that
I didn't teach there. The reason I didn't teach was that when I got there, I
found that all the teaching was so circumscribed by state laws that I didn't
want to get involved in it. Also, I knew that if I started teaching courses,
people then would expect me to go on doing so. So I kept out.
BOHNING: There are a number of things you did when you were in Chicago. The book
on hyperconjugation came out then in 1962. I remember
that book. In fact, I have a copy with me here.
DEWAR: That was fun, because I had given a notorious lecture on
02:02:00hyperconjugation, proving that it didn't exist. [laughter]
BOHNING: I also wanted to ask you about George Wheland, because you refer to his
work in a number of your papers. He was an early figure in much of the early
quantum mechanics in organic chemistry. Did you meet him at all?
DEWAR: Oh, yes. I knew him very well in Chicago. By that time, he was coming
down with multiple sclerosis. He was already very under the weather with it. He
hardly came into the building at all. I met him on my visit to the U.S. in 1957.
02:03:00BOHNING: I was just curious how he viewed your approach to things.
DEWAR: We got on very well. I don't think we ever had any real arguments.
BOHNING: What about the book on hyperconjugation? How was that received when
that came out?
DEWAR: I don't really remember.
BOHNING: That was the Ronald Press. They put out some good books in those days.
DEWAR: They did, yes. That was one of the early ones.
BOHNING: You also got into organometallic semiconductors in Chicago. How did
that come about?
02:04:00DEWAR: This was just an idea I had, a new class of semiconductors that I had
predicted on theoretical grounds. We decided to make one example of a polymer
just to provide an excuse for publishing the idea. I
never did any more work in the area, because I was unlucky. First, the student I
had studying the problem became interested in theory and took to doing
theoretical calculations instead of experimental work. Then I assigned the
problem to a postdoc who was totally incompetent. He was nice, but really
02:05:00hopeless. So I never did any more work on the problem. I still think it's a good idea.
BOHNING: Did you have any computer facilities available?
DEWAR: No. Chicago had a computer, but I hadn't taken to computation when I went
there. It was also very expensive. You had to pay for every second at the full
02:06:00commercial rate. The thing which got me started on computing was an invitation
from Bell Telephone Labs. After I'd been in Chicago for about a year, 1960, I
think it was, they asked me if I'd like to go there for a month in the summer
and just do anything I liked and give them two or three seminars. This became an
annual event. I went there every year. They let me use their computer, so that
got me going. I also got to know Larry Snyder very well and I managed to get him
to write a program for the pi-SCF method.
02:07:00BOHNING: I think while you were still in Chicago there was a conference, and you
had one paper on resonance and conjugation in which you said that resonance
effects are very generally less important than has commonly been
supposed. This came out of the 1958 conference on hyperconjugation.
DEWAR: No, that was earlier. I published two papers on this. The first was one
with Howard Schmeising. The hyperconjugation conference was later. I'm trying to
think when the conference on hyperconjugation was.
BOHNING: The date I have here is 1958, which would have been before you came.
02:08:00DEWAR: I was over in the summer for visits in 1958 and 1959. So that would be
right, because it took quite a time then for the papers to appear in print. The
paper appeared in 1959, so the work was done earlier. Then there was the split p
BOHNING: Yes. The SPO method. Split p orbital.
DEWAR: I was dabbling around at that time with calculations. The name was
suggested by an Argentinian chemist, Nora Hojvat. She's now Nora Sabelli; she
married another Argentinian and is at the University of Illinois in Chicago.
02:09:00She's quite well known in the theoretical area. She had been doing calculations
on very small molecules of interest in astronomy. I put her on to this work. My
idea was that electron correlation should tend to make two electrons in a p
orbital stay in opposite lobes and that the way to allow for this was to treat
the lobes as individual orbital functions. Nora's English was very good, but not
perfect, so she described the halves of p orbitals as split p
orbitals. I said, "That's a marvelous term!"
[laughter] It upset people terribly. Everyone came up with arguments showing
that the whole treatment was a lot of nonsense. In fact, it's quite
02:10:00sophisticated. I was able to meet all the obvious criticisms without difficulty.
The only valid objection which someone finally came up with after about six
months, was that the orbital lobes are not orthogonal to the core orbitals, and
this upsets things.
BOHNING: At this point there was a lot of work on pi complexes and the tropylium ion.
BOHNING: How did the tropylium ion follow from what [William von Eggers] Doering
02:11:00DEWAR: It was when Roly Pettit was with me in London. We set out to make
tropylium. Our original idea was to make it from the appropriate
cycloheptatriene carboxylic acid, which [Eduard] Buchner had reported. One other
way was the halogenation and dehalogenation of cycloheptatriene, but we kept off
that because we knew Bill Doering was working on it. We lost out on the
carboxylic acid route because we believed Buchner's formulae for the isomeric
cycloheptatriene carboxylic acids. He had reacted benzene with ethyl
diazoacetate and depicted the product as having a norcaradiene structure with a
three-membered ring. Isomerization of this was claimed to lead to a
cycloheptatriene carboxylic acid with the carboxyl attached to the saturated
02:12:00carbon in the ring. We tried about a dozen ways of turning this into tropylium,
none of which worked. Also, we did not try the obvious one, i.e., Curtius
degradation to a chlorocycloheptatriene, because we knew that Alan Johnson was
trying that, so we left it to him. When we failed to get tropylium by the
fourteenth method we tried, I heard from Johnson that he had abandoned work in
the area. He found that Curtius degradation led to a urethane which hydrolyzed
extremely easily to form just urethane itself. He assumed this was because the
tropylium ion was so stable.
This seemed to us nonsense. As soon as we heard that he was doing no more work
02:13:00on it, I told Roly, and within a day, he had got this urethane, hydrolyzed it,
and found cycloheptadienone as the other product. So it was obvious that the
urethane was in fact an enone. Buchneil acid was in fact the one we wanted, a
cycloheptatriene with carboxylic attached to the saturated carbon. Every single
synthesis we had tried gave tropylium when we repeated them with the "right"
acid. So for about a year we'd been isomerizing the acid we wanted to something else!
In the meantime, Bill Doering played a dirty trick on us. He just read the
02:14:00literature. He found that [Jacob] Meisenheimer had a compound in about 1890
which he described as being a chlorocycloheptatriene, but with properties which
obviously were wrong. He said it was a crystalline solid. Doering repeated
Meisenheimer's work and showed that the compound was in fact tropylium chloride.
BOHNING: You did an awful lot of work on boron nitrogen compounds during the
period in Chicago.
DEWAR: Yes. That was a sort of stable diet which we carried on for quite some time.
BOHNING: How many graduate students and postdocs did you have in Chicago?
02:15:00DEWAR: I really don't know offhand. I know the total number I've had is getting
on to about two hundred fifty or something like that. We've kept in touch with
them, or did for many years, in official annual newsletters, but lately these
have become a bit spasmodic. Did I send you a copy of the latest newsletter?
02:16:00DEWAR: I must look around and see if I have one. I'm sure I have.
BOHNING: That would be nice.
DEWAR: You might find it interesting, because we tracked down all except two or
three of the people in my group and kept touch with them. This has all their addresses.
BOHNING: There was another paper on electrophilic addition to
olefins. You looked at the sterochemistry of adding
deuterium halides to acenaphthylene in which everybody had said it was trans and
you found that it was mostly cis.
That's interesting. Why did you try this experiment?
DEWAR: I really wanted to know what happens. We were looking for evidence for pi
02:17:00complex intermediates. The question here was whether when you attach a proton to
another bond it forms a carbonium ion or a pi complex. There really was no
information about that.
BOHNING: During those four or five years in Chicago, were you developing more of
a relationship with American physical organic chemists?
DEWAR: Oh, yes. In 1957, I spent nearly six months over here and traveled all
02:18:00over the country and saw practically everyone, and I kept up close contacts with
all those I met. I visited again in 1958 and 1959 before we moved to Chicago,
traveling around a lot each time. Those times I was just on my own.
BOHNING: You mentioned something earlier about Texas. You were only in Chicago
four years. Were you thinking of leaving Chicago? Were you specifically thinking
of looking somewhere else?
DEWAR: Oh, no, not at all.
BOHNING: It was just that Texas came along?
DEWAR: Yes, Texas came along. It was one of these really wild things.
BOHNING: When did you first meet Hackerman?
02:19:00DEWAR: In 1957, on my big trip to America. That was when Roly Pettit's first
wife developed schizophrenia and her family, who were wealthy land owners in
Australia, came over and carried her off back to Australia. Roly was very broken
up, because he was very much attached to her. They wanted him to go back to
Australia because they were buying her a farm. She had been told she had to live
a totally quiet life. Roly refused to do that, because he said that only thing
he had left was chemistry. He wrote to her every day for eighteen months and she
never replied, so eventually he divorced her. He really wanted to get away to
somewhere entirely different. Just at this point Bill Doering had heard that
they were looking for chemists at Austin. He knew Roly because he had visited me
02:20:00often in London, starting in 1951. He used to visit us regularly. So he told
Texas about Roly. When we went in 1957, it was just when they were considering
him. When we left Yale, we drove all around the country in an ancient car we had
bought. We made a trip to Austin specifically so I could tell Norman Hackerman,
who was then the chairman of the chemistry department, about Roly. So that's how
we first got there.
BOHNING: What was the state of the department in Austin when you went there? Was
it still building, or were you in on the ground floor of his new regime?
DEWAR: The Chemistry Department had some quite good people in it. However, they
had very little equipment.
02:21:00BOHNING: Was the Welch Foundation money available?
DEWAR: That had been going for quite a long time.
BOHNING: Did you go there as a Robert Welch professor?
DEWAR: Yes. I wouldn't have considered going otherwise. This was a research
chair, so I didn't need to do any teaching. I certainly wouldn't have been
prepared to go to a State University otherwise.
BOHNING: But you said they were still short on equipment.
DEWAR: The department was, but I managed to get a small NMR spectrometer. It
took me quite a time to build up my own group.
02:22:00BOHNING: How was Hackerman as a Chairman? Was he supportive?
DEWAR: By the time I went he was Vice President and Provost, and after that he
became the President. [William] Shive was the Chairman. He was a biochemist. The
thing about the place was that Billy was indirectly related to Norman and knew
him very well. Billy was terrified of causing Norman any problems, so he never
spent any money because he didn't want to cause Norman budgeting difficulties.
Norman also was unwilling to do anything for the Chemistry Department because he
was afraid of being accused of partiality.
BOHNING: That's not the best combination.
02:23:00DEWAR: It's a very bad combination. Texas A&M, which had no inhibitions of that
kind, ended up with far more equipment than Austin had.
BOHNING: Texas A&M attracted some pretty good names in chemistry too. Derek
Barton went there, and [F. Albert] Al Cotton.
DEWAR: Al Cotton, yes. Al Cotton was the one who really put the place on the
map. It was hardly known before. His going there was a great shock to everyone,
but the truth of the matter was that he had always had right wing views, and the
situation at MIT with the war in Vietnam made him move somewhere to the right of
Hitler. The second thing was that he enjoyed horses and had never been able to
02:24:00do anything about it. There, he was able to get a ranch.
BOHNING: Who else was at Austin at the time?
DEWAR: There really wasn't anyone much. In organic chemistry there was Phil
02:25:00[Philip S.] Bailey, who was there because of his life work with ozone. But
otherwise, the other people were practically very little known. In physical
chemistry there were quite a number, like Stuart Rice. But it was lacking in
people with any real standing.
BOHNING: When did that department really start to grow?
DEWAR: The sad thing is that having got me, they should have gone all out to
bring in more top people, and they never did. This is the combination which I
just mentioned of Billy not wanting to spend money and Norman not wanting to do
anything special for the Chemistry Department. My going there suddenly put the
place on the map, and the place did have money for hiring young people. We were
02:26:00getting extremely good young chemists but were unable to keep them, and we did
not make a single high level appointment. It was about twelve years before they
even tried to get anyone else at a high level. The best they got was Dick
[Richard B.] Bernstein, who only stayed two or three years. When Norman left,
the whole place fell apart.
[END OF TAPE, SIDE 5]
DEWAR: His successor was a totally incompetent person called Spurr. Norman had
always kept the whole place running superbly, the only problem being his desire
02:27:00to spend as little as possible. Norman's attitude was that the purpose of the
administration was to serve the faculty, and his duty as the chief
administrative officer was to see that they bloody well did, which was an
unusual attitude. But it was wonderful for us. Everyone in the administration
wanted to help one if they could. If you had any sort of hassle with any of
them, you could always bring it to an end by saying, "I'll have to take the
matter to Norman Hackerman." They knew that you would, and they knew that Norman
would listen. And they knew that if Norman thought they were being stupid and
bureaucratic, he'd have the shirts off their backs. With Spurr, the whole place
fell just apart and totally disintegrated. In the end I just got fed up with the
02:28:00situation and left. I can't remember who was appointed in my place. I go blank
with people; it's awful.
It's probably a sign of Alzheimer's disease, except that, as Mary says, if it
were I'd have been suffering from it from the age of twenty. Oh, yes, it was
Josef Michl. I was largely responsible for his going there. But it's a sad
business, because he wasn't treated at all sensibly. He also got fed up with the
02:29:00place and left and so did his successor.
BOHNING: While we're on that subject, why did you make the move here from Texas?
DEWAR: At the end I got totally fed up with the place. Spurr was bad enough, and
his successor, a woman whose name I forget, was even worse. She was put in as a
stopgap because at the time, they weren't able to get anyone else to take the
02:30:00Presidency. The Regents fired Spurr after four years. They put her in as a
stopgap on the grounds that she only had four years to go until retiring age. If
they'd known how bad she was going to be, I doubt if they would have. Finally,
when she left they got a really good president, Peter Flawn, who was excellent.
He did a tremendous job in cleaning the place up. At this point, the trouble
with the university was that the State Legislature got their fingers into the
place and, even worse, so did the State Board of Control. The next thing that
had to be done was to get them out. I think that at this point the Regents
refused to go along with Flawn. It's pure guesswork on my part, but I think
02:31:00that's what happened. When he took the Presidency he said he would only accept
it on the condition that he had total support from the Regents to make the
University a top-level university. He would leave immediately if he felt he was
not getting full support from them.
His successor was from the business school. A youngish man. I think he got his
degree in advertising. He was a total disaster. Every promise that had been made
to get me to go to Texas was broken by these creeps. One of these was that I
would be able to remain indefinitely after retirement on a half-time basis as
long as I wanted and the University wanted. Furthermore, the Department voted
unanimously that I should be allowed to keep my chair full-time because there
02:32:00were only two or three years until the thing would become moot anyway. I went to
this President asking what he intended to do, and I couldn't get him to reply
for two and a half years. Finally, I got a note from him while I was in
Gainesville, terminating my appointment. I was incensed. We went out and looked
at houses, saw one we liked, and bought it. Why Gainesville? Because we had
already decided to come here when I retired. We knew the place well, having
visited here a lot, and knew a lot of the people here.
However, at this point the Texas Legislature rushed through an emergency bill
abolishing retirement age at universities in Texas. The story is that the
President first heard about it when he read about it in the student newspaper!
They hadn't even bothered to tell him! Why they didn't, I don't know. Everyone
thought this action was because of me, but I don't think it was. [laughter] But
anyway, I stayed on a year because I had people in my group finishing whom I
02:33:00wanted to see through, and I also rather enjoyed rubbing the President's nose in
I really meant to retire when we came here because there are lots of things I
have always wanted to do and never had time for. I had really looked forward to
giving up chemistry, but when the Department here heard I was coming, they
immediately rushed around and offered me a professorship, so here I am for a bit
longer. There is still one piece of research I really want to finish; I think
I'll stay until I do that.
BOHNING: Here you certainly have a group of people interested in the same area
DEWAR: Oh, yes. That of course is how we got to know Gainesville.
BOHNING: They have been here for some time. I've forgotten what it's called, but
there's an institute here in quantum chemistry.
02:34:00DEWAR: Quantum Chemistry Project, I think it is. It has never affected me in my
work much. I've always worked entirely on my own. I never interacted with people
to any great extent, maybe because I never was able to do so early on. But I
think that's just the way I operate. I like to think of things on my own.
BOHNING: I've heard people say that there is an advantage to that in the sense
that their thinking is not cluttered by input from other people.
DEWAR: This is absolutely true. When I went to Courtaulds to work with Bamford,
02:35:00we began work on polymerization without either of us knowing any of the
literature about it. We only read it up later. I think that was a good thing. We
did it quite deliberately. We said, "If we read the literature, we won't do
anything new. If we set off to do things that seem to us interesting, we
probably will." That's true. If you read too much about an area before starting
work in it, it's very difficult to think of anything new in it.
BOHNING: What were the computing facilities like in Texas? Did they develop
there at all for you?
DEWAR: Oh, yes. Furthermore, they never charged for use of the computer. Now, of
course, that is quite normal, but at that time it was very unusual. The computer
02:36:00they had was a CDC-1604, which was similar to the IBM-7090, one of the better
computers at the time. But after I'd been there just two or three years, Norman
Hackerman decided that if they were going to make the university one of the top
ones in the country, there should be some area where it was absolutely on top.
So Texas was the first university to buy a functioning CDC-6600. There were two
earlier ones, but ours was the first which really functioned properly from the
word go. At that point, we had the best computing facilities in the world. No
one else had a 6600 which worked. Unfortunately, it wasn't kept up when Norman
02:37:00left. UT let things slip. So we didn't keep up that position. It was actually a
great pity; they should have done it and they would have if Norman hadn't left.
However, there still was a problem. Since anyone could use the computer,
everyone wanted to, to show their intellectual superiority. So most of the time
available was taken up with pointless calculations while those who really needed
the computer were kept waiting. In the end I solved the problem by getting a
grant, with matching funds from UT, to buy a computer of my own. It was, if I
remember rightly, VAX 1178. While the VAX was of course slower than the 6600,
having it all to ourselves for 24 hours a day meant that we could get far more
02:38:00done. Now, of course, the introduction of work stations and PCs has transformed
the situation. The computer I now have at home is a lot faster than the 6600 and
cost several hundred times less.
02:39:00BOTH NING: Let me follow up on something you said earlier. You said you still
had something you wanted to finish here, and I wanted to ask you what that was.
DEWAR: Oh, yes. For the last fifteen years my real goal has been to get an
effective theoretical treatment of transition metals. We tried very hard, and we
finally came to the conclusion that it simply cannot be done using the formalism
we had in MNDO or AM1. So we are now calculating integrals theoretically and
then scaling them by a function of distance, to allow for correlation. This is
something we tried years ago in Austin, but at that time the extra computing
02:40:00time needed was so great that we couldn't even try it. In fact, the whole of my
work on theoretical chemistry has been limited simply by the current state of
computers. My purpose has always been purely practical, to get methods which can
be applied to real chemical problems. That means doing calculations for quite
big molecules, and for reactions of quite big molecules. The treatment we used
at each stage in the work was limited to the least awful approximation that
allowed one to do calculations at all. Now computers are faster, so we can do
things better. We have got going on this quite well, and I'm sure we can produce
something useful in a year or at the most two years. I have lots of ex-members
of my group who can carry on once we do it. The difficult part in developing a
new method is always the first step. Once the basic method has been developed
02:41:00for one element, it's easy to extend it to additional elements. In this case
there shall be no big problem in extending it to transition metals.
BOHNING: Where have the two hundred and fifty students or so that you mentioned
before gone? Are they mostly in academic positions?
DEWAR: No. Many are in academic positions, but I think the majority went into
industry, national laboratories and things like that. I've always impressed on
my students that they shouldn't go into teaching unless they enjoy teaching for
its own sake. I think one of the troubles is that people go into teaching
thinking it's a nice soft option and one that will let them do research. I've
02:42:00always pointed out to my students that the research done in industry is just as
intellectually interesting and in some ways a lot more challenging. A lot of my
best people have gone into industry and done very well in it.
BOHNING: How did you find getting support? I see that you had a lot of support
from the Air Force. You talked earlier about the problems in England, but once
you got to Chicago and into Texas, how did you find getting support?
DEWAR: In Chicago there were no problems at all. I had seven grants from
different agencies. After I left Chicago, quite early on at Austin, most of
02:43:00these grants continued. I hadn't run into problems starting up at Texas because
of the Welch Foundation. The amount of money I got from it was only about a
quarter of what I had had, but I got it right away. However, everyone thought
that because of the Welch Foundation people at UT didn't need money at all. I'd
never had a research proposal turned down in my life until I went to Texas. I
didn't even in England. But now I did. I was in real trouble `till one day I had
a telephone call from Amos Homey, who was head of the AFOSR [Air Force Office of
Scientific Research], or the chemistry branch of it. He said, "Are you going to
be in Washington soon?" I said, "No." He said, "Well, I want to see you. Could I
come and see you in Austin?" I said, "Fine." He said, "What about tomorrow?" I
said, "Well, that's fine." So he arrived and said that he had decided that,
instead of spending all his money on small grants to lots of people, he was
02:44:00going to spend a good chunk of it taking up the whole research support of four
people, and he asked me if I would be one of them. After giving this due
thought, I graciously agreed, and AFOSR has in fact been my main source of
support ever since. I couldn't have done the work I've done without it, because
it gave me total freedom. It let me work on absolutely anything I wanted. As
time went on, the dollar decreased in value and a point came when AFOSR could no
longer support all of my research, but they still went on being my major source
BOHNING: Did you give the Welch money up altogether when you got this, or did
you keep Welch support?
DEWAR: No, the Welch I kept. It was, as I said, about a fourth or a fifth of the
02:45:00total. Because of silly restrictions, it was in fact far less useful per dollar
than any of my other sources of funds. This goes back to the origin of the Welch
Foundation. Welch was a bachelor who had no family at all, and he made a huge
amount of money out of oil. His only friend was a young chemist called William
Milligan. When Welch died, he left all his money to set up the foundation to
support chemistry in Texas, making Milligan director of research at the
Foundation for life. It's an indication of his ability that shortly after the
02:46:00Welch Foundation was founded, Milligan came up for tenure at Rice and in spite
of the Welch Foundation, they turned him down. [laughter] Not suprisingly, he
ran the Welch Foundation in a rather strange way.
BOHNING: They certainly have sufficient funds, because the amount of support
they give out is quite large.
DEWAR: It started out with thirty million dollars, and when I was there in Texas
it got up to between forty and fifty million. I think now it's over two hundred million.
BOHNING: Where do you think physical organic chemistry is today? You've seen it
02:47:00develop over a long period of time now.
DEWAR: I've been unhappy about it for a long time. I think it's getting better
in the sense that traditional physical organic chemistry, which consisted of
studying kinetics and mechanisms of reactions, became totally sterile many years
ago. I found I'd been nominated about twenty years ago for the ACS Award in
Physical Organic Chemistry. I was the third person to be nominated. The first
two were Winstein and Ingold. I asked for my name to be taken off the list on
the grounds that I would consider it an insult to get the award and so be
02:48:00labeled a "physical organic chemist." [laughter] I did in fact eventually get
it. Mary Anne Fox in Austin didn't know about this and nominated me and I didn't
want to let her down, so I said, "Yes."
I think it's got to be a real mess for most of the people in it. They're just
floundering around doing experiments without really proving anything. The good
part is obvious. For example, the development of new techniques like NMR that
have now been taken over by organic and inorganic chemists. As for reaction
02:49:00mechanisms, I have always thought they can be studied effectively only by
combining experiment with theory. You have to have experiments, but they should
be combined with theoretical calculations. This of course is now becoming
BOHNING: With respect to the kinds of calculations you've been doing for a while
now, are other people working in the same area using the techniques you've developed?
DEWAR: Oh, yes. An increasing number of people. Very much so, in fact. We have
of course had total hostility from the word go from most of those in the ab
initio area. This isn't true for the people at the top. I'm on very good terms
02:50:00with them. But the rank and file still regard me as a menace. This is really not
surprising. The area first developed around about 1960 when computers first
became available, and [Robert S.] Mulliken was going around saying how all the
problems of chemistry would soon be solved by quantum mechanical calculations.
Everyone was pouring out money in the 1960s to support work in the area. At that
time, the only calculations you could do were for diatomic molecules, and these
were so bad that they didn't really mean anything. There were in fact only two
or three second rate people doing such calculations. All the good theoreticians
were in other areas. Mulliken himself never did any calculations. Neither did
02:51:00[John S.] Slater and all the other top people. The people doing work in that
area were, to say the least, mediocre and they were moreover physicists with no
knowledge of chemistry. The students they got were therefore not only the dregs
but the dregs of those in the physics departments, with absolutely no knowledge
of chemistry. So when Chemistry Departments were hiring faculty in the new area
of Theoretical Chemistry, these were the people who got the early faculty
positions. Later, when the area began to become interesting, and chemistry
students wanted to learn about it, these were the people they studied under.
The methods being used now were developed, I think, by [John] Pople in the
1950s. He abandoned the whole approach in 1958 on the grounds that it could
never give really accurate results. His conclusion was that you have to include
02:52:00interelectronic distances in the wave function. People had found this already
early on in the case of the helium atom and the hydrogen molecule. There was
nothing new about it. There must be a way for doing this. [C. C. J.] Roothaan
published one approach and he was working on two others when he died, but
nothing has been done since. When I first came across this, people were doing
calculations using very primitive ab initio methods which didn't mean anything.
The energies they calculated were terrible, so the only way they could get
sensible results was by introducing adjustable parameters. But they weren't
testing their methods to see if this was true, because they didn't want to waste
computing time on it. As I have often said, this is the first time in the
history of science that people have been allowed to carry out and publish
02:53:00calculations using untested empirical methods.
I became interested in the area by pure accident. In Chicago, I had a student
who wanted to carry out MO calculations. So I put her on to doing some
semi-empirical ones using Pople's pi-SCF method. To my amazement, this worked
incredibly well. In fact, the final form of that treatment is probably the most
accurate quantum mechanical treatment that's been developed. It gives heats of
formation in aromatic hydrocarbons at least as accurately as they can be
measured. This convinced me that, following this approach, one could end up with
a general treatment of molecules which would be really accurate. So I tried
02:54:00including all of the electrons. When we started work on this area we were very
restricted by the limited capabilities of the computers then available, but we
kept going and we started getting results. We've had total hostility from the
beginning from the so-called ab initioists, because what I was claiming was that
we were able to do things at least as well as you could by ab initio methods
that needed a thousand times more computing time. This naturally upset people in
the ab initio area.
[END OF TAPE, SIDE 6]
DEWAR: Most of the ab initioists were moreover doing calculations using programs
other people had written. Most of them couldn't possibly have written the
programs themselves. There are still a lot of very second-rate people in the
02:55:00area. The good ones I'm on good terms with; I have no trouble with them. But
unfortunately, places like NSF and editors of journals have lists of
theoreticians to send things to as referees, and half of these "official"
theoreticians are people who really are no damn good and have very strong
feelings about what I'm doing. It's been very frustrating. Until I got into this
area, I never had problems with referees. I had always welcomed referees'
comments. Even when they were offensive, they were always helpful. If they were
offensive, it was usually for good reasons. I was glad to have been prevented
from doing something wrong. But in the theoretical area, from the word go I had
02:56:00nothing but obstruction and personal insults. It's been very distasteful.
BOHNING: I won't ask you who the players are on the negative side, but who are
the players on the positive side, the ones who are in the top rank?
DEWAR: The good ones? Well, Fritz Schaefer is obviously doing very good work.
There are two or three others. Mike [Michael C.] Zerner. He's one of the few
people in the semi-empirical area. John Pople, of course, is very good. I've
02:57:00never had trouble with him. I'm on very good terms with [Per-Olov] Lowdin.
BOHNING: At one point there was something that came out of Indiana University,
involving an exchange of computer programs.
DEWAR: Oh, yes, the Quantum Chemistry Program Exchange.
BOHNING: But that's no longer in existence, is it?
DEWAR: Oh, no, it's still going strong.
BOHNING: It is? I used to get something from them and then it sort of
disappeared. I thought it folded.
DEWAR: Oh, no. But now you have got to pay for most of their literature and ask
for it specifically. It's going from strength to strength. It's in terrific
shape. It's a very good thing.
BOHNING: Who started it?
02:58:00DEWAR: I don't know. It was one of the quantum chemists at Indiana.
BOHNING: Jerome Karle once told me that for a lot of the work he was doing, they
had written a lot of their own programs. At one
point, somebody came in trying to sell him a commercial program. He insisted
that he wanted to see the code. Not the results; he wanted to see the code. When
he looked at it, it was a program he had written, and someone was trying to sell
it to him.
DEWAR: [laughter] Life is like that.
BOHNING: Are there any problems like that now?
DEWAR: Oh, yes. There are a lot of similar problems in that area. One of the
things that I think unfortunate is that people in the area now have settled on
02:59:00this as a way of making money. John Pople and several other people have set up
companies to exploit their work. I've never done this. I've always made all of
our programs freely available. Also, one advantage of being treated as a sort of
pariah is that no one else has tried to get into the same area. Young people who
might want to wouldn't be able to get research support to do it. Another thing,
too, is that developing semiempirical procedures is a hellish business. It's
extremely laborious and it needs an enormous amount of computation and people
with the patience of saints. It also really needs someone with some curious kind
of special ability.
03:00:00The advances we've made have always been when I've got someone who just happened
to be good. The effect of this is that I've been able to prevent these methods
from proliferating. In my group, I always had a fixed rule that people could
make changes in our procedures, and they could do calculations using them if
they wanted, but I would not publish the results. Anything to be published had
to be done with the official procedures, so you didn't get all sorts of
different bits and pieces. As a result, our "official" methods are unique. In
actual fact, all methods now are essentially empirical. Even in the best ab
initio methods, the errors in the absolute energies of molecules are gigantic.
So the only way they can work is by a cancellation of errors, and the only way
03:01:00to tell whether or not they do cancel is by trial. In the ab initio area, there
must be four or five hundred different methods to choose from and hardly any of
them have been properly tested, or indeed tested at all. No one knows how well
In our case, because there are so few procedures, each has been thoroughly
tested. Apart from the fact that we've done a lot of calculations ourselves,
other people have used them too, so it's a huge body of knowledge as to how well
they work, and you know where you are. The only exception to that came recently
with the one personal problem I've had with someone in my group. The only lemon
I've ever had in it. This was Jimmy [James P.] Stewart, who came to me as a
postdoc on a leave of absence from a faculty position in Scotland to write
03:02:00programs. When he arrived, I gave him the job of taking our programs, which were
then all in bits and pieces, and putting them all together in one big package,
which he did very nicely. I called this MOPAC, Molecular Orbital Package.
However, when he was leaving, he claimed that this was his program and he was
going to take it with him and take full charge of it. I didn't want bloodshed
and I didn't want to wreck his career, so I just let him take it and we set up
our own program called AMPAC. That's why there are two different programs,
unfortunately. AMPAC is in fact much better, because it was written from scratch
by Daniel Liotard who came to me from France, and was a much better programmer
The other thing was that Jimmy got on to trying to find a successor to MNDO. We
03:03:00had in the end decided that we couldn't get d orbitals into MNDO, and there were
also various things wrong with it which we were unable to correct. In MNDO,
there was far too much repulsion between non-bonded atoms. One way to deal with
this was just to put additional terms into the core repulsion function. We had
tried this earlier, but it hadn't worked because it increased the computing time
too much, and we couldn't handle it. Jimmy also tried this and wrote a program
03:04:00for it. Unfortunately, he wouldn't listen to any advice. He had his own ideas on
how to do it and went ahead. I told him he was going the wrong way, but he
wouldn't believe me. After eighteen months, he came up with what he said was the
final version. I discovered it had charges of half a unit on hydrogen atoms in
paraffins in addition to other failings. It just gave the right numbers and he
was going to tally by these. His view was that all you had to do was to get the
numbers right by state optimization, and if anything was wrong, then you just
put in more molecules and went on in a sort of brute force method. It doesn't work.
At this point, I took the project away from him and gave it to a graduate
student, [Eve G.] Zoebisch, who started again from the beginning. The resulting
treatment, AM1, was entirely due to her. One other
member of my group helped, but she really did all the work. I duly gave them
03:05:00both credit for it. Jimmy was outraged. He's a very arrogant person. I'd never
had problems of this kind with anyone else before. He went off to the Air Force
Academy and proceeded to come up with a new version of AM1 which he called PM3.
There are things about this which are grossly wrong, and people are coming up
with more and more things wrong about it. In any case, it certainly isn't a big
advance on AM1. This was done just to show that his approach worked. The whole
affair was very irritating, because in the first place, it would have been much
better for him if he'd been at all reasonable. He could have got a great deal
out of working here with me. As I have already said, he was good at programming.
03:06:00He just wasn't very good at deciding what to program.
BOHNING: Are there any other areas that you think we should cover? Is there
anything else that you'd like to add?
DEWAR: I don't really think so. We've covered most of them. There are lots and
lots of things we've done, of course.
However, there are two recent things we've done which could be really important.
One was to show that activation barriers to reactions can be due entirely to
03:07:00desolvation. You do it quite slowly. In the hydrolysis of esters, for example,
in the gas phase there isn't any barrier at all. The barrier in solution arises
entirely from the need to desolvate an ionic reagent, in this case hydroxide
ion, before it can attach a neutral ester. As I have pointed out, this idea
provides a very nice explanation for the way enzymes function. They function
simply by getting rid of the solvent in between the reagent and the grouping of
the substrate which is going to react with it. This in fact is now becoming
generally recognized. You can speed up ester hydrolysis by some twenty-five
03:08:00orders of magnitude by going to the gas phase. There is therefore no difficulty
in explaining the high rates of enzyme reactions.
BOHNING: I noticed that several of your recent papers dealt with enzymes.
DEWAR: Yes, two. In fact, if it weren't for the PNAS
[Proceedings of the National Academy of Sciences], I couldn't have published the
work, because the papers I sent to biochemical journals were sent to enzyme
chemists to referee, who thought my idea nonsense. I probably wouldn't have been
able to publish it at all. So I sent it to PNAS, which doesn't referee papers
submitted by members of the Academy. Enzyme chemists all around were absolutely
outraged, not so much by the theory I put forward, but by the fact that somebody
who wasn't an enzyme chemist had the effrontery to come up with a new idea in
this area! [laughter]
03:09:00This is really one of the worst things about American science. I think many
people in it tend to treat it as a religion. Everyone has their own fixed
beliefs, and they defend them to the death. They regard any attack as a personal
affront. It's just like denying some basic principle of Christianity. The worst
thing, of course, is that science is now being divided into smaller and smaller
compartments, and the people in each compartment resent any intrusion from the
outside. In a lot of compartments the people aren't even that good. There's a
general agreement that "experts" in any area are the sole reliable authorities.
But of course, "experts" in some areas are more expert than those in others, so
03:10:00in many areas the only way you can get new ideas is from outside. It really is a
bad business. I've had this more often than most people because I do wander
around a lot; I have come up with a lot of new ideas, and they frequently have
been ones which were unorthodox by the standards of the day. The enzyme one is
the most intriguing.
BOHNING: And yet the general public has the feeling that scientists are these
marvelous, open-minded, unprejudiced, unbiased people.
DEWAR: Oh, it's totally untrue. They're the most prejudiced and biased people
around. I think it's worse in this country than most, because this is a very
religious country. It has a tradition of religion. Even if people aren't
religious in the ordinary sense, they absorb this sort of general religious
03:11:00attitude at an early age. So they really get upset by their beliefs being challenged.
I have a lovely example of that in the controversy over the norbornyl cation. I
was the one who originally suggested the interpretation which made it reasonable
for ions of this type to be stable, because the resonance description doesn't
explain that at all. In terms of resonance theory, radicals and anions should be
just as stable as cations, because you can write exactly similar resonance
structures for them. In terms of MO theory, only cations can be "nonclassical,"
because in the case of radicals or enions, one or two electrons have to go into
anti-bonding orbitals. So I had a vested interest from the beginning in the
norbornyl cation being nonclassical. In fact, I'm the only person involved in
03:12:00the controversy who ever changed sides. I changed sides partly because of new
experimental evidence and partly because our theoretical calculations indicated
that norbornyl cations should not in fact be symmetrical. I remember I got a
letter from George Olah, who's a very old friend of mine, but is one of the main
protagonists for the non-classical structure. He begins, "Dear Michael, how can
you do this to me after all these years?" [laughter] JACS sent my paper to
Herbert C. Brown at Purdue to referee, and he said it was "the most important
03:13:00contribution to theoretical chemistry in the last fifty years."
BOHNTNG: What about Paul Bartlett? Didn't he at least oppose the idea of a
non-classical ion, at least the name?
DEWAR: I don't recall. I have always had a very high opinion of Paul. Not at all
liable to get stuffy ideas. Things have got much worse lately. One particularly
sad thing is that journals have changed too. In the old days, when you had a
single editor of JACS, the editor developed a sort of megalomania and basically
03:14:00didn't give a damn about hurting people's feelings or what they thought. He did
what he thought was right. I have a wonderful example of that, relating to a
past editor of JACS, Marshall Gates. This concerned my infamous "half-electron
03:15:00model." Let me tell you how this developed.
In MO theory, each MO represents the motion of an electron under attraction by
the nuclei and repulsion by the other electrons. Since each MO can hold only two
electrons, the ground state of a normal "closed shell" molecule is one where the
2n electrons occupy in pairs the n MOs of lowest energy. The occupation number
of each MO is therefore zero or two.
The repulsion between two electrons occupying different MOs depends on their
spins. Other things being equal, the repulsion between electrons of similar spin
is less than that between electrons of opposite spin. This is because according
to the Pauli Principle, two electrons with similar spins cannot be at the same
place at the same time, and if the probability of them being at the same place
is zero, then the probability of them even being close together is also reduced.
So the repulsion between the alpha spin electron (x) in an a MO (A), and the two
electrons occupying some other MO (B), are not the same. The repulsion between x
and the alpha spin electron in B is less than that between x and the beta spin
electron in B. This, however, is balanced by a similar difference in repulsion
between the beta spin electron (y) in A and the electrons in B. So since all the
MOs are empty or doubly occupied, all the electrons are moving in similar
potential fields, in accordance with the MO picture in which they occupy similar MOs.
03:16:00Consider now a radical. Here there is an electron (z) with no partner. If z has
alpha spin, the repulsion between it and the alpha spin electron in B is less
than that between z and the beta spin electron in B. So now it is no longer
correct to assume that the "paired" electrons occupy similar orbitals. The MOs
occupied by the alpha and beta spin electrons are different. One cannot
therefore treat a radical by standard MO theory simply by specifying an
occupation number of one for the singly occupied MO. This leads to major complications.
It occurred to me to wonder what would happen if one could replace z by a pair
of "half-electrons," imaginary particles with half a unit of charge and half a
unit of spin. In this case the symmetry between alpha and beta sin electron
would be preserved so one could still use standard MO theory. The only
difference would be a spurious energy term representing the repulsion between
03:17:00the "half-electrons." This, however, can be easily calculated, being just
one-quarter of the term in the standard treatment that represents the repulsion
between two whole electrons in the corresponding AO. So we tried this out by
carrying out calculations for a number of radicals and found that our simple
approach gave results in good agreement with sophisticated methods that needed
far more computing time.
I then discovered that there was in fact a good mathematical justification for
our procedure. Indeed, I discovered later that this had been published years
before by Leslie Orgel in a paper which everyone had
forgotten. However, I wrote up our work in terms of
03:18:00our picture of "half-electrons" just for fun, to see what would happen, and sent
the paper off to Marshall Gates. It came back with violent reviews from two
referees, one of whom indeed clearly nearly had a heart attack. He wrote three
pages, saying, inter alia, "After the split p orbital monster, here is something
even worse, the half electron." [laughter] However, Marshall included a friendly
letter, saying that while my idea was clearly wholly heretical, he was quite
prepared to publish it, but had I any changes I would like to make in view of
03:19:00the referees' comments. I had in fact a second "respectable" version of the
paper in which we developed the mathematical treatment of the approximation and
then pointed out the amusing physical picture that corresponded to it, and that
is what actually appeared in print. But if I had
stuck to the original version, Marshall would clearly have published it,
regardless of the referees' comments.
This couldn't possibly happen nowadays because editors have to accept the
opinions of referees. I once wrote to one of the present Editors of JACS about a
paper I had submitted, pointing out the stupidity of the comments of one of his
referees. He wrote back, "How can I possibly send this to him or publish your
paper? If I did, it would hurt his feelings, and I can't afford to upset our
03:20:00referees because then they wouldn't referee papers." Very curious and very unfortunate.
I might add that I would hate to have papers published without their being
refereed. I have too often been saved by referees' comments. Indeed, in my time
I have withdrawn a number of papers because referees pointed out omissions or
errors that I had overlooked. It also doesn't worry me in the least if referees
choose to be personally offensive. I just want the editor to act as a fair judge
if I point out errors in their comments and not to reject my papers out of hand
because of comments by self opinionated people, hiding behind a cloak of anonymity.
BOHNING: What do you think of the quality of the students today at the graduate
level, compared to over the years that people have been working for you?
DEWAR: Oh, I think they're very good. I have no complaints. Things have become
harder and harder for them, because chemistry is becoming such a huge subject,
but I think they're okay.
BOHNING: In that respect, then, do you see more and more specialization in
chemistry education as people focus in on narrower areas?
DEWAR: It's very difficult. I think the problem with education really goes back
earlier, that far more should be taught in grade school. The level reached in
03:21:00grade school here is really appalling, far behind Europe. That's where things
get so backward, and it continues to a large extent in high school. High school
is the place where people should get their general education. When they get to
the university, they should specialize far more than they do here, and things
should be taught at a much higher level.
BOHNING: But does that narrower focus stifle creativity? In your own example,
your ideas moved around quite a bit, and yet I know people who, if it's not in
their one area, they don't want to hear anything about it.
DEWAR: Very true. It's a different attitude. Some people just like staying
03:22:00completely in one area and some don't. I don't; I have always wandered about,
not just in chemistry but also elsewhere.
BOHNING: Have you done any writing outside of chemistry, given your classics
background and everything else?
DEWAR: No, I never have. I have a book I'd like to write, but I don't know if
I'll ever get time to write it. I think the only thing I've done outside was a
paper which I was persuaded to send to Science, which rejected it. It was on the
fifty-five mile speed limit. If you look at the evidence, published in full by
the National Research Council as a little paperback, it fails to show that the
03:23:00fifty-five mile speed limit has saved a single life at all. The arguments NRC
give are total nonsense. As I said earlier, the experts in different areas
differ in expertise, and after all, the study of traffic isn't something which
attracts high-grade minds, so you wouldn't expect great intelligence there or
people who had been properly trained in scientific principles.
[END OF TAPE, SIDE
DEWAR: My contribution related to statistics in Texas. Just before we went to
Texas, the state raised the speed limit on all roads--two-lane as well as
divided highways--from sixty to seventy. I thought that a very nice gesture,
03:24:00recognizing that I was coming. According to present ideas, this should have led
to absolute mayhem because cars on the roads were far more dangerous then than
they are today. If decreasing the speed limit to fifty-five saved lives, then
raising it from sixty to seventy should have led to a massacre. But in fact, if
one analyzes the statistics properly, one finds there was a decrease of six
percent in the death rate on Texas roads that year.
My argument was really quite simple. The majority of deaths on the road occur in
collisions between cars. Such collisions are analogous to the collisions between
molecules involved in a bimolecular reaction in the gas phase and their number
03:25:00should likewise depend on the square of the particle (car) density. Why the
square? If cars travel twice as fast, they will get to their destinations in
half the time so there will, on average, be half as many on the road at any
given time. The chance that a given car will be involved in a collision in a
given length (x) of road is then halved. Since there are half as many cars on
the road, the chance of a collision in x is therefore reduced by one half times
one half equals one quarter. However, since the cars will be travelling twice as
fast in a given period, the net reduction in collisions is one quarter times two
equals one half. Doubling the speed should therefore halve the death rate. This
of course doesn't take account of accidents not involving collisions. Nor does
it allow for the limited abilities of drivers, which means that higher speeds
make them more likely to lose control of their vehicles. However, the statistics
in Texas showed quite unambiguously that the death rate on roads did in fact
fall the year the speed limit was raised from 60 to 70. So the safe limit at
that time, in Texas at least, was certainly not less than 70 miles per hour, and
now that cars are safer, it would probably be higher. In any case, the 55 miles
per hour limit must certainly have killed at least four or five thousand people
03:26:00in Texas alone.
BOHNING: Is there anything else you'd like to add at this point?
DEWAR: I can't think of anything specific.
BOHNING: I'm curious about your interactions with a number of people.
DEWAR: Ask any questions you like.
03:27:00BOHNING: You mentioned Carl Djerassi earlier. You made some comments that I was
intrigued by and wondered why you felt the way you did about him.
DEWAR: I think he's a show-off. He's extremely conceited and I think he thinks
everything revolves around him. I have nothing against him other than that. I've
only met him a few times and haven't talked to him a great deal.
BOHNING: That's one of the reasons I asked you that question, because Djerassi
is writing novels and Roald Hoffman is writing
poetry. I wondered whether you might be involved in
doing some things like that.
03:28:00DEWAR: Well, I have tried to do some writing, but neither poetry nor novels. I
don't think Carl's novels are a going to be a contribution to literature.
BOHNING: They haven't had very good reviews.
DEWAR: They certainly haven't, have they? [laughter] I must admit, I have
similar feelings about Roald's poetry too.
BOHNING: I just found one of his books and I was reading it before I came down.
There's a lot of chemistry in his poetry, anyway.
BOHNING: At least in terms of chemical terms. Since most of your work's been theoretical
DEWAR: In volume, though, it hasn't. I think more than half is experimental.
BOHNING: I know your heterocyclic work goes on and on and on, but I guess
DEWAR: At one time I had a group of about twenty-five people; I thought that was
03:29:00too many, and it shrank. As it shrank, my theoretical work was becoming more and
more interesting. I also found that it's very difficult to do both. I would get
people whom I would put onto an experimental project, and then, being in my
group, they would decide they would like to find out how to do calculations. The
next thing I knew, they were doing calculations and I couldn't get them back
into the lab. I had three or four really good experimental projects that were
never finished because of that.
BOHNING: What do you think comes first, the experiment or the theory, in your
own approach? You get a new idea and you know it has both theoretical and
experimental implications. Which would you approach first?
DEWAR: One would obviously carry out calculations first, because they're so easy
03:30:00to do. The thing about experimental work is that it's very time consuming and
very expensive. You should get any help that you can from theory. This has been
my point. The methods we've developed have been really intended for organic
chemists to use themselves. We developed them because as an organic chemist I
wanted them for my own use.
That person is my postdoc. He's Chinese and extremely good, one of the best
people I've ever had. He's a senior faculty member at the University of China.
He was with me for about two years in Austin and went back just before the
03:31:00Tiananmen Square affair. I got a message from him saying he thought he could get
out if he got an invitation to a conference. So I got him an invitation to a
conference in Austin, the Southwest Theoretical Conference. Then I got another
message. He couldn't write to me but he wrote to a Chinese member of our group,
saying that he thought if he got an invitation, he might be able to get his wife
and child out too. So I wrote him saying that I'd be delighted if he could stay
on longer and would support him as long as he could stay, and that if he did
manage to come I hoped he would bring his wife and daughter with him, because we
would so much enjoy meeting them. To my surprise, he managed to get all of them
out. Now, of course, he can't go back. So he's the one who's working on this new
thing. I have another Chinese friend of his who's coming next month, but I'm not
03:32:00having more than that. [I need] two just to work on this project.
BOHNING: That's what you have going now, just these two?
DEWAR: That's what I'm planning to have. I don't want more. I'm really going on
very largely from a sense of duty. If I don't do this, no one may, and I think
it's something that needs to be done. As I have maintained all along, there is
no use having a theoretical treatment if it is useless. A treatment which you
can't do calculations with is useless even if it's one hundred percent accurate
in principle. So my object all along has been to get treatments which are good
enough to be useful and at the same time can be applied by people to problems
03:33:00arising from their own experimental work. More and more people are using our
methods now, very rapidly. For example, someone who's at Eastman Kodak in
Rochester about eighteen months ago did a survey of chemical pharmaceutical
industry. He found that of the money spent on computing, forty percent was being
spent on calculations using our procedures and less than one percent on ab
BOHNING: That's certainly a good test of your methods.
DEWAR: [laughing] Well, industry doesn't spend money without some good reason.
We ourselves have come up with quite a number of things. Our calculations have
led to a complete revision of ideas about pericyclic reactions, and I think now
03:34:00we've got the situation concerning them on very firm ground. Relatively few of
them are genuinely synchronous. There's a simple reason for this. In the
Evans-Polyani picture, the transition state is a structure where the bond(s)
that break are partly broken and the bond(s) that form are partly formed. If a
reaction involves synchronous breaking of two bonds instead of one, the energy
of the transition state should be double that of one for an analogous reaction
in which just one bond is broken. So an alternative path involving breaking of
the two bonds in two separate steps should be correspondingly favored.
A pericyclic reaction is a two-bond reaction, so it should tend to take place
03:35:00nonsynchronously. However, the Synchronous Transition state [TS] can be written
as a hybrid of reactant-like and product-like structures, and if the resonance
between them leads to sufficient stabilization, the synchronous process may be
preferred. This is the reason why M. G. Evans originally came up with the idea
of aromatic transition states back in 1938. It occurred to him that the
transition states or a synchronous Diels-Alder reaction is like benzene, with
six orbitals overlapping, and should therefore be aromatic. So that's really how
he got the idea originally.
But it's obviously touch and go whether specific pericyclic reactions are or are
03:36:00not synchronous; the Cope rearrangement certainly isn't synchronous. The
Diels-Alder reaction, I think, is in most cases not. That's another thing we've
come up with. The other I've mentioned already is the possibility for
desolvation to be the whole factor in determining a rearrangement reaction.
BOHNING: I don't have any more questions at this point, and I've enjoyed
spending the last four hours with you.
DEWAR: [laughing] Yes, you must be worn out!
BOHNING: No, I've enjoyed it very much, and I want to thank you for taking the time.
DEWAR: You're very welcome.
[END OF TAPE, SIDE 8]