How brilliant innovators propel the field of chemistry | Interview with Dr. Harry Gray

How brilliant innovators propel the field of chemistry | Interview with Dr. Harry Gray

We met with Dr. Harry B. Gray to discuss the rivalry between physicists and chemists, problems in charge calculations, Arnold Beckman, and much more. Enjoy!

Noted chemist Dr. Harry B. Gray explores electron transfer chains in photosynthesis, problems in charge calculations that led to the development of ligand field theory, his experiences with Arnold Beckman, and the rivalry between physicists and chemists. Arnold O. Beckman Professor of Chemistry at California Institute of Technology and founding director of the Beckman Institute for Advanced Science and Technology, Dr. Gray talks with Dr. Jed Macosko, academic director of and professor of physics at Wake Forest University.

Walked into the Chemistry Department in Havemeyer Hall... Walked into the chairman's office with all my bags and everything. And he looked at me and he says, "Who the hell are you?" [chuckle] And I said, "I'm Harry Gray, you offered me a job." He says, "Oh, yeah, Harry Gray, we did offer you a job. Glad you're here, here's a book, you're teaching a course tomorrow."” – Dr. Harry Gray

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Interview with Chemist Dr. Harry B. Gray

Interview Transcript

(Editor’s Note: The following transcript has been lightly edited to improve clarity.)

0:00:25.8Inorganic chemistry tools

Jed Macosko: Hi, this is Jed Macosko at Wake Forest University and AcademicInfluence. And today we have visiting us from Caltech, Professor Harry Gray, who is a chemist par excellence. So, Professor Gray, I want to know…

Did you get to work on the electron transfer system that Mel Calvin was doing at UC Berkeley, and was that part of your repertoire or did you work with other people when you started applying your inorganic chemistry tools to some of the things that happened inside of life?

Harry Gray: I never worked with Mel Calvin in research, but he was a good friend, and I was on committees with him. I remember I was on a nice committee in Colorado with the... What’s now the Renewable Energy Institute in Colorado. We were at...

Mel and I were involved as advisors when they started that, so we had a lot of interaction and we were good friends, and I did work on some systems that he worked on, but I never worked directly with him, so that he was a pioneer in photosynthesis, but he never really got involved in the kind of fundamental electron transfer work that I got involved in, so my work was really sort of orthogonal to his work, but I think he followed some of my work before he passed away, and we were very good friends.

Jed: Yes, and I could see how they’d be orthogonal, he was really trying to uncover the proteins that cascaded up...

Harry: Yeah, he uncovered the Calvin cycle and which he won the Nobel Prize for, and I was more interested in the electron transfer chains and how they operated through the photosynthetic reaction center, and how the holes are delivered to the catalytic center that makes oxygen, and that was my main interest and he was...

Some of his co-workers were very involved in the oxygen evolution stuff, but of course, he was the guy responsible for the Calvin cycle that... The dark reaction that forms carbohydrates. And so my work was complementary and we talked about it, and I think he liked it, but...

Jed: I’m sure he did.

Harry: I’m not sure, he was a pretty tough character and he might... He might have thought that I was off doing crazy things, a lot of people did. I liked him a lot. He was a really cool guy.

0:03:19.8Beyond the mean-field theorem

Jed: Yeah, yeah, I got to meet him when he was late in life. Well, I bet it was really nice for you to see how quickly your ligand field theory took on, I learned about it in the early 1990s when I was an undergraduate, and it was taught alongside the mean-field theorem.

Can you tell us a little bit about what the breakthrough was that allowed you to go beyond the mean-field theorem?

Harry: Yeah, well, you know, the crystal field theory was the physics theory that I started with, and I was offended by the crystal field theory because first of all, it was invented by physicists, and chemists think physicists look down on us as sort of second-rate physicists, so we have a thing about the physicists.

But the reason I was offended by it, it took away the chemical bonds, there weren’t any bonds in the crystal field theory, they replaced chemical bonds with point charges and point dipoles, and they could only explain the colors of compounds that the first row transition, metal ions and aqueous solution, the...

They couldn’t explain what we call charge transfer transitions and transitions that we call intervalence transitions and things like Prussian blue. Some of the deeply colored things, they couldn’t explain the color of permanganate, potassium permanganate.

And so most of the things I was interested in, the crystal field theory couldn’t explain. And Pauling... Linus Pauling’s theory was even worse. And valence bond theory couldn’t explain the colors of anything.

And so I decided to... That Robert S. Mulliken at Chicago had invented something for organic chemistry called molecular orbital theory, and I thought, but it couldn’t be applied to inorganic compounds, because inorganic compounds have metals and ligands, and there’s a lot of charge separation in the bonds and Mulliken’s theory could not account for that.

So what I did, the breakthrough I did, was to develop a way of correcting the diagonal elements of energy and calculations for charge, and so I could iterate the system and correct for the charges on the metal ions and the ligands, put the bonds back in through this modified Mulliken theory.

And then I took the best part, the only good part of the crystal field theory, which is the atomic physics of electron and electron interaction, so you can calculate excited state energy as multi electron excited state.

So I made this hybrid Mulliken MO model for the bonds to put the bonds back in with my corrected diagonal elements and I introduced the one-center electron-electron interaction theory from crystal field theory.

So that hybrid model is what’s called Ligand Field Theory, and I put that together and did some of the first calculations of it in the early ’60s. And the first calculation I did was in Copenhagen as a post doc... And by the way, just for your information, based on my development of that theory, I got a job... I got an offer from Columbia University Chemistry Department without an interview.

Jed: [chuckle] Wow, that is impressive.

Harry: I had not applied for a job there. One day, a letter appeared in the mail in Copenhagen from the Chemistry Department chairman Charlie Beckman at Columbia, whom I did not know, and I had never been at Columbia University and I hadn’t applied. They didn’t have my CV, they didn’t have anything, but they had some information about my work in Copenhagen, and so they simply made me an offer of a faculty job at Columbia.

I took it [chuckle] I took it. When I showed up at Columbia from... I took a flight from... It took 44 hours on the Icelandic airlines to get from Copenhagen to New York ’cause we stopped about six times, and I’ve... I arrived... I was 25 years old, I arrived with all these bags and I got... Stuck my head and took a taxi from what was called Idlewild Airport then, it’s called JFK now.

I took a taxi to Columbia 116th and Broadway, and I walked into the Chemistry Department in Havemeyer Hall... I walked into the chairman’s office with all my bags and everything, and he looked at me and he says, "Who the hell are you?" And I said, "I’m Harry Gray, you offered me a job." He says, "Oh, yeah, Harry Gray, we did offer you a job. Glad you’re here, here’s a book, you’re teaching a course tomorrow."


Harry: That’s what the theory got me. It got me a job at Columbia University without an interview, without a CV, without any proposals, without anything that you have to go through now to get a job.

Jed: Wow, that’s great. Well, you gotta tell us more about your interaction with Charlie Beckman, we all know Beckman, centrifuge, stuff like that.

Harry: Well, that was Charlie Beckman, it was not Arnold Beckman .

Jed: Oh, okay.

Harry: You’re talking, Jed, you’re talking about Arnold Beckman, the great inventor. I met him much later.

Jed: Okay. Alright.

Harry: Charlie Beckman was not any relation to Arnold Beckman.

Jed: Okay, so just the same last name.

Harry: I don’t need to tell you any more about him, except he offered me a job. [chuckle]

Jed: Okay, but you worked with Arnold Beckman, and that’s why you’re at Caltech.

Harry: Yeah, I did a lot, I did a lot of work with Arnold Beckman I can tell you about that, if you like. I’m very talkative, Jed, so you can shut me up and...

Jed: Well, just tell us how you first met him and how did you end up doing further...

Harry: Yeah, I will, I will. Well, I went to... I did well at Columbia, I was promoted to a full professor in three years or so, because I was developing theory and doing all sorts of new things and...

And I was very, very lucky, Jed, because I got into this field very early, extremely early, inorganic chemistry was undergoing this renaissance, it had been a very boring field up until the theory got into it, and people started understanding mechanisms and spectroscopy and all of this stuff, which they had no idea before.

I mean, inorganic chemistry before the ’60s was really... The courses were really dedicated to understanding the production of sulphuric acid [chuckle] and exciting things like that.

Of course, then the theory came in and mechanisms came in, and all of a sudden inorganic took off, it was called the renaissance of inorganic chemistry.

And all of a sudden it exploded, and there were only about three or four young folks like me in the country who had been trained, who knew anything about this new theory, so we were all in enormous demand and we got multiple offers, we got offers from schools all over the country, because the universities across this country had no courses, they weren’t teaching this new stuff because they weren’t... There wasn’t anybody around to teach it.

And so there were just a few of us, there was Dick Holm, there was a guy named Al Cotton, Dick Holm, and Dick Carlin, and just a few of us, John Fackler, me, Alan Davison , and we were getting offers from every place ’cause we were the young Turks in the field.

Jed: Cotton was the guy who wrote the textbooks, right?

Harry: And so I had multiple offers, I had offers from Caltech and Stanford and every place you can think of during this time, but I stuck it out at Columbia, trying to build the field at Columbia, but Columbia’s department was pretty small and was dedicated with... Emphasized organic and physical chemistry, and they told me that, "Look, Harry, you’re doing great here, but we’re not big enough to expand your field." So that’s the reason I took the offer from Caltech.

Jed: I see.

Harry: Caltech, JD Roberts was the chair there, and they kept after me to take the job and I finally said, "Okay, I’ll take it," even though I didn’t want to leave New... I love New York. Our family love New York.

We didn’t want to leave Columbia, but it was clear that if I wanted to build this field in directions like energy, organometallic chemistry and biology, something called bioinorganic chemistry, which I got started in.

So I wanted to build it in all those directions, solid-state and solar energy conversion, but I wanted to build a field by hiring more faculty, I had to go to some place which was really big enough to do that, and Caltech was.

Jack Roberts said, "We want you to come here and build the field, hire people, and really cover all areas of the field, ’cause we’re very, very interested in building this." So that’s why I decided to move to Pasadena in 1966.

Jed: Wow, that’s amazing that you went over there.

Harry: And then how I met Arnold Beckman, I got to... Arnold Beckman was the chairman of the board at Caltech. He was the chairman of the Board of Trustees.

So as soon as I got to Caltech, they asked me to give a big talk, a big talk about my work in front of alums and the Board of Trustees, and all of these folks. And in 1967, a big crowd, I talked about how I had gotten into biological... Gotten my theory into biological areas, and particularly into iron metabolism and iron storage and things like that, and so I gave a talk on how I’d gotten into this.

And Arnold Beckman and his wife, Mabel, were in the second row, I hadn’t met them yet, but they were in the second row, but he didn’t know who I was, but I knew who he was [chuckle] as he was extremely famous for his invention of the pH meter and mainly for his invention of the spectrophotometer, the COD spectrophotometer called the Beckman DU, which I had done...

Most of my PhD thesis was done on that instrument, and so he was a big hero of mine, and he was in the second row with his wife, and normally I would be nervous, but I’m not nervous.

I love to talk and I absolutely... I only get nervous when people don’t let me talk. And so I really went all out. I mean, I came with everything. I was going crazy in this talk, and you can imagine what it’s like, ’cause I talk to people in the audience, I call them out, and I think in the middle of the thing I said, "Dr. Beckman, I bet you don’t understand what I’m talking about, do you?" [chuckle] And stuff like that.

…Mabel Beckman looked at me and looked at Arnold, and she said, "Arnold,"… "I didn't understand a word this young man said, but boy, did I like the way he said it."” – Dr. Harry Gray

So after the talk was over, he and Mrs. Beckman, Mabel Beckman, came down to the front to meet me, they wanted to meet me, and they said, "Well, we enjoyed your talk," and then Mabel Beckman looked at me and looked at Arnold, and she said, "Arnold," she said, "I didn’t understand a word this young man said, but boy, did I like the way he said it." And Arnold gave me the thumbs up then, and I knew that... I knew I had a lifelong friend.

Jed: Oh, that’s great.

Harry: And so we bonded, we bonded and we became... My wife, Shirley, and I became really close friends with the Beckmans.

When I became chairman of the division at Caltech, we met with them essentially every week, we would go down to Orange County and he would take us to the Newport, Newport Yacht Club, where he was member number four, and he lived to be 104.

And so even then he was quite elderly, but he was member number four of the Newport Beach Yacht Club, and the next guy living was, I think member number 170. Anyway, that’s how I got to know him, but we became close friends together...

Jed: Oh, God.

…and finally I came up with the idea of building an institute that would develop technology, that would develop new instruments…” – Dr. Harry Gray

Harry: And when I became chairman, he suggested that he would like to make a gift to Caltech, and we worked on his first gift, which was the Beckman Synthesis Center, and then he came to me later and said, "Well, I like what you did there. I want to do something really big at Caltech," and that’s what led to the Beckman Institute.

So we worked together on that, and I suggested several things to him that he didn’t like, and finally I came up with the idea of building an institute that would develop technology, that would develop new instruments and technology, which is what of course he did. It would be an institute to develop tools and had centers that would support research by folks doing biology and chemistry and medical research, and so that really hit the spot with him and he said, "Okay, that’s it, Harry, I want you to do that." [chuckle] So that was... That’s the Beckman Institute. And it still is.

0:18:29.2Sign off

Jed: Awesome. Well, thank you for giving us that background and I’m sure we could have such a wonderful conversation about all the things you’ve done, but since our time is short, we’re just going to have to thank you one more time for joining us today, it was really, really fun.

Harry: Well, this has been such a wonderful time to meet you and Brian and your daughter was wonderful. She’s a wonderful young lady. I’m sure you’re super proud of her.

Jed: I am.

Harry: And maybe I’ve talked her into going into chemistry.

Jed: You may have, you may have, so we’ll see. [chuckle]

Harry: So, thanks so much, Jed, for this and thanks for putting up with me.

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