Tag Archives: Paul vonR Schleyer

Paul Schleyer (1930 – 2014) R. I. P.

This is a guest post by Peter J. Reilly, Anson Marston Distinguished Professor Emeritus, Department of Chemical and Biological Engineering, Iowa State University, fellow Schleyer undergraduate advisee Princeton 1958 – 1960, friend, and all around good guy.

I’ll follow with my own reminiscences in another post. Obits tend to be polished and bland, ‘speak no evil of the dead’ and all that, but Peter captures the flavor of what it was actually like to be Paul’s advisee and exposed to his formidable presence.

“Following are my thoughts on our undergraduate chemistry advisor at Princeton, Paul von Ragué Schleyer, who died on November 21 of this year at 84.

Paul was an amazingly prolific chemist. He started publishing in 1956, soon after he arrived at Princeton from receiving a Ph.D. at Harvard, where he studied from 1951 to 1954 after earning an A.B. from Princeton. He was still publishing at the time of his death. In fact, he had promised to deliver a book chapter over this Thanksgiving weekend. Over his latter years at Princeton, in the early 1970’s, his annual production of papers averaged the middle 20’s. He kept up the same pace at Universität Erlangen-Nürnberg in Germany from 1976 to 1992. From 1993 to 1997, when he had appointments at both Erlangen-Nürnberg and the University of Georgia, he was in the 40’s. When fully at Georgia, after 1997, he gradually slacked off, publishing only 16 papers this year. Altogether he had 1277 publications, when a really productive chemist with ready access to students and postdoctoral fellows hopes to have 200–250 in a full career.

Another way to consider Paul’s productivity is by how often his work had been cited (partly by his own later papers but mainly by the papers of others). A 1981–1997 survey reported that he was the third most cited chemist in the world. Althogether his works were cited over 75,000 times. His h-index is 126 in the Thomson Reuters Web of Science database, meaning that he had 126 publications that were cited at least 126 times, an astounding number.

I first met Paul in the fall of 1958, two years after I arrived at Princeton. I needed to find someone to supervise my junior paper, a ritual common to all Princeton undergraduates doing A.B. degrees. I had originally approached Edward Taylor, a somewhat older chemistry professor, but when I told him that I was somewhat interested in becoming a chemical engineer, he directed me to Paul. Paul was 28 at the time, but he seemed older to me (I supposed all professors did). He was tall, with dark black hair combed to the side over his forehead. He had a scar on his cheek and talked very precisely.

My father met him once and came away asking if he had been a German U-boat captain during WWII.

I must say that I spent a sizable part of the next two years being terrified of Paul. He had a laboratory in the second floor of the southwest corner of Frick Chemical Laboratory. The benches were full of glassware, to the point where it seemed hard to do any research. However, the item that spooked me the most was a cauldron full of boiling black liquid, supposedly mainly nitric acid, in which dirty glassware was submerged to be cleaned.

Paul gave me a project to research the incidence and properties of the benzyne intermediate, a short-lived benzene ring with a triple bond. This was my first exposure to research beyond short papers for classes, and I suppose that I did well enough for him to invite me to do a senior thesis with him. The topic was to determine the mechanism by which an obscure organic chemical rearranged itself. The title of the thesis that came from a year’s dogged effort was “A Study of the Cleavage Products of 2,5-Dimethyltetrahydropyran-2-Methanol”, but what I mainly made was black goop. Paul’s written comments to me started with the statement that he was sorry that the problem was so intractable, but at least he liked my writeup. I still have the thesis (and the junior paper). Back in 2007 I was contacted by the Princeton University Library, which had lost its copy. They asked if I could send them mine so that they could microfilm it, which of course I did.

I remember that at least four of us chemistry majors spent much of our senior years in a very large and empty laboratory working on our theses under Paul’s direction. I must say that the various chemicals that I worked on smelled a lot better than the ones that you dealt with. I used to take weekend dates up to the laboratory to show them where I worked, and I would open one of your very small tubules, I think containing butyl mercaptan. Its smell still permeated the room on Mondays. (Editor’s note — people used to look at their shoes when I walked into the eating club after working with n-Bu-SH or similar compounds).

Despite my lack of success on my thesis, I learned from it how to do research. My chemical engineering major professor at the University of Pennsylvania was hard to contact, so much of my doctoral dissertation was done without much supervision. Between the two experiences, I had a good foundation for my 46 years of being a chemical engineering professor, six at the University of Nebraska-Lincoln and 40 at Iowa State University after four years at DuPont in southern New Jersey.

I only saw Paul four times after leaving Princeton. The first was when I returned there for a short visit. The second time was at my 25th Princeton reunion, when one of his daughters was graduating. A third time was when he visited the Iowa State chemistry department to present a prestigious lecture. The fourth and last time was in 2005 when I visited the University of Georgia for a meeting. Paul spent about 30 minutes telling me about his latest research, of which I understood very little.

I will close with a little story. When I told Paul during my senior year that I wanted to go to graduate school in chemical engineering, he asked why I wanted to become a pipe-fitter. Probably because of my chemistry background at Princeton, my research was always chemistry- and biology-based, first in fermentations at Penn and Nebraska (with a detour to chloro- and fluorocarbons at DuPont), and then in enzymes and carbohydrates at Iowa State. I moved more and more into computation late in my career, and when Paul visited around 2002 I told him that I would be sending a manuscript to the Journal of Computational Chemistry, which he and Lou Allinger at Georgia had founded and were still editing. Being Paul, he immediately said in his deep voice that it had better be good. As it turned out, it sailed through the review process with hardly a blip, and I followed it up with a second manuscript a few years later.

So, we were fortunate to have Paul as a mentor during our formative years. He certainly wasn’t the sweetest guy, but he was brilliant, and hopefully a very small part of his brilliance rubbed off on us.”

Peter J. Reilly


Schleyer is still pumping out papers – crystallization of a nonclassical norbornyl cation

It’s hard to know if anyone cares about this any more except the original protagonists, most of whom are long gone (RIP H. C. Brown), but a huge controversy raged for decades on whether a nonclassical cation (e.g. not representable by a Lewis structure) existed in the fused ring system of norbornane and its derivatives. Science vol. 341 pp. 62 – 64 ’13 contains a truly definitive answer (hopefully) along with a lot of historical background should you be interested. An Xray crystallographic structure of a norbornyl cation (complexed with a Al2Br7- anion) at 40 Kelvin shows symmetrical disposition of the 3 carbons of the nonclassical cation. It was tricky, because the cation is so symmetric that it rotates within crystals at higher temperatures. The bond lengths between the 3 carbons are 1.78 to 1.83 Angstroms — far longer than the classic length of 1.54 Angstroms of a C – C single bond.

The controversy was still exercising physical organic chemists decades later — here are some notes from an earlier post when I was going through Anslyn and Dougherty’s book. “661 -> 664 — Fascinating to see the ‘answer’ to the questions about classical and nonclassical norbornyl cations that so exercised Schleyer and many other chemists back in the late 50′s and early 60′s. Stable ion media and solid state NMR (both unknown at the time) did the trick. Not finding distinct NMR structures at 5 degrees KELVIN is good enough evidence (for me) that nonclasical norbornyl cations exist. Also if the barrier to interconversion of 2 norbornyl cations is under .2 kiloCalories/mole, this makes the controversy essentially irrelevant at room temperature and above, where the average thermal energy/molecule is .6 kiloCalories/mole. Even if two forms actually exist, it’s got to be like keto-enol tautomerism. A fascinating conclusion to the controversy.”

Historical note. Schleyer was my undergraduate advisor back in the day in ’58. He is now 83 and is the last chemist standing. Bravo ! ! !

It will be interesting to see if letters to Science disputing this work emerge in the coming weeks.