Nature Chemistry | The Sceptical Chymist

Reactions – David Lemal

David Lemal is at the Department of Chemistry at Dartmouth College and works on the synthesis and chemistry of unusual organic species – both stable and short-lived – and in the mechanism of organic reactions.

1. What made you want to be a chemist?

Chemicals and their transformations first intrigued me at a young age in the form of a ChemCraft chemistry set with its colorful array of exotic solids and liquids. I graduated to a basement lab stocked with chemicals that I bought at Eimer & Amend in New York City, and a friend of the family bestowed upon me a bottle containing several pounds of potassium chlorate. Thus, with some sulfur and charcoal I was able to make as much of my own variation on gunpowder as needed.

When I reached high school, however, sports and girls eclipsed chemistry in my pantheon of interests, and taking the lone chemistry course hardly changed that. Students never got to touch a chemical, nor did the teacher, with two exceptions — he used the carbon dioxide fire extinguisher to blast students who talked in class, or doused them with ammonium hydroxide. He never gave a chemical answer to a student query. “It’s just because the good Lord made it that way” or “You’ll get it when you go to college” sufficed to handle any question.

As a premed in college, I found myself taking comparative anatomy and organic chemistry simultaneously. I didn’t enjoy cutting up animals, but I had a great time in the “orgo” lab. These experiences set me on the path to becoming a chemistry professor. As those were the days of DuPont’s “Better things for better living through chemistry,” there was added inspiration for my career choice.

2. If you weren’t a chemist and could do any other job, what would it be – and why?

Science and technology have always interested me more than any other vistas on the intellectual landscape. I would be happy as a biologist, but nowadays that would mean doing chemistry, so I must make another choice. Engineering appeals to me, especially the biomedical variety with its notable successes and bright prospects for the future.

3. What are you working on now, and where do you hope it will lead?

The focus of my research is fluorocarbon chemistry, a branch of organic chemistry in which fluorine substitutes for the hydrogens that form the “skin” of most organic molecules. Fluorocarbons differ dramatically in properties and chemical behavior from their hydrocarbon counterparts, with the result that they have found many applications in our culture for which they are uniquely well suited. The overarching goal of my work is to contribute to our understanding of the effects of fluorine substitution on organic molecules. My coworkers and I typically choose molecules that we expect to display properties and chemistry that are unusual even for fluorocarbons; e.g., highly strained, energy-rich, very reactive molecules. We then try to synthesize them in order to explore their nature and behavior.

At present, I am trying to synthesize highly fluorinated bicyclo[1.1.0]butanes. My quantum mechanical calculations predict quite remarkable reactivity for these compounds as a consequence of both the severe strain in their bonds and the character of their fluorine substituents. I look forward to testing these predictions.

4. Which historical figure would you most like to have dinner with – and why?

Marie Curie would be my choice. Garnering Nobel Prizes in both chemistry and physics is a phenomenal feat for anyone. What an accomplishment for a woman at the beginning of the 20th century! When I was very young, seeing a movie about her discovery of radium was a source of inspiration for me to pursue chemistry.

5. When was the last time you did an experiment in the lab?

This morning. A key reaction on the path to a target molecule had gone awry, yielding an unexpected product. Today’s experiment – isolating and purifying that product – was necessary for determining its structure. With that in hand, I hope to understand the errant chemistry.

6. If exiled on a desert island, what one book and one music album would you take with you?

It would depend on whether I was marooned on, or luxuriating on that island. If the former, I would take along a copy of Laura Hillenbrand’s Unbroken, a wonderful story about survival under unbelievably difficult conditions. If luxuriating, I might opt instead for Kumar’s Quantum, a fascinating history of 20th century physics focusing on the decades-long dispute between Albert Einstein and Niels Bohr over the nature of reality. As for a music album, I would choose a selection of top hits from the great broadway musicals.

7. Which chemist would you like to see interviewed on Reactions – and why?

Albert Eschenmoser. Deserving of a Nobel Prize for his highly creative work on the synthesis of Vitamin B12, not to mention his many other impressive contributions to synthetic and mechanistic organic chemistry, Professor Eschenmoser is also a gracious, generous, unassuming man with a fine sense of humor. There is no one in our profession that I admire more.

OR – Edward C. Taylor. Now the A. Barton Hepburn Professor of Chemistry Emeritus at Princeton University, Ted has capped a highly productive and distinguished career with the discovery, in conjunction with Eli Lilly, of Alimta, a blockbuster anticancer drug. Exuberant and vigorous at age 88, he could pass for 60. It is really hard not to envy this guy!


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