Nobel Prize winner delivers Lord Lecture

Dr. Robert Howard Grubbs discusses contributions to chemistry field

Allegheny students and faculty gathered at Ford Memorial Chapel to experience a different kind of speaker on Monday Sept. 21. Nobel Laureate Dr. Robert Howard Grubbs, professor of chemistry at the California Institute of Technology, engaged an audience of students, teachers and community members in the 2015 Lord Lecture.

Shaun Murphree, department chair of chemistry, made the introduction to the lecture series, and Mark Ams, assistant professor of chemistry, introduced the night’s speaker.

Grubbs began the night’s talk with a brief primer on organic chemistry and the nature of experimental catalysis.

“A lot of people aren’t chemists here, so what is organic chemistry?” he asked. “It’s the chemistry of carbon and hydrogen bonds, of carbon compounds and of putting things together. It’s the basics for plastics and food. You’re made out of a lot of organic compounds.”

Grubbs regaled his career’s work in the subfield of organic chemistry that deals with chemical catalysts. Catalysts are a class of particles that allow for certain reactions that would otherwise be unfeasible to take place.

“For example, If you take hydrogen, and you mix it with oxygen, you can leave them alone for centuries and they won’t do anything,” said Grubbs. “But if you introduce a catalyst then, boom! They explode.”

These reactions usually involve breaking and rebuilding molecules that are constructed around the element carbon, known as organic molecules. Organic molecules and the catalysts used to prepare them are used commonly throughout academia and industries.

“If you want to make new molecules, you have to break bonds and know how to put them back together,” said Grubbs.

Grubbs has taught chemistry at the California Institute of Technology since 1978. He also heads the Grubbs group, which investigates new catalysts and reactionary pathways.

The Grubbs laboratory has made several contributions to the field of organic chemistry, and its practical applications in industry, including the discovery of a family of catalysts used in the olefin metathesis reaction.

The olefin metathesis reaction involves the breaking of olefins, a certain class of organic molecules, and the reassembly of double-bonds between carbon atoms to form new olefin molecules. The process is used to generate pharmaceutical drugs, renewable biofuels and insect pheromones.

In 2005, Grubbs, Dr. Yves Chauvin, a French chemist, and Richard Schrock, a chemist at the Massachusetts Institute of Technology, collectively won the Nobel Prize for Chemistry for the discovery of this mechanism. Grubbs credited Chauvin with the greater part of the discovery of the stepwise process by which olefin metathesis occurs.

During the award ceremony for the Nobel Prize, the reaction was explained by a choreographed dance that involved dancers representing different atoms, molecular groups and catalysts. The dancers changing partners represented particles that broke off from one another and reformed chemical bonds to create new molecules.

After receiving the Nobel Prize, Grubbs was invited to a number of prestigious social functions, many of which he spoke about during the lecture.

“So if you do everything right, you get to meet with the King and Queen of Sweden,” he said.

One process that the Grubbs group worked on was ruthenium metathesis. This particular reaction plays an integral role in a series of processes that can produce renewable jet fuel and other biofuels from seed oil derivatives.

“One of the things that was mentioned [at the Nobel Prize ceremony] is that catalysis can be used to make a lot of ‘green’ stuff,” Grubbs said. “And so the Nobel Committee got really excited about this. I didn’t really realize that I was a ‘green’ chemist until they told me about it.”

Green chemistry, also known as sustainable chemistry, involves synthesizing chemicals from sustainable starting materials and using cleaner processes for the environment.

One such green project the Grubbs group has developed is the synthesis of insect sex pheromones. Pheromones are a class of biomolecules that allow for animals of the same species to recognize each other, usually for the purposes of mating.

As an alternative to pesticides, the Grubbs group has worked out a method to mass-produce a sexual pheromone, known as the Peach Twig Borer Pheromone, that disrupts the mating behavior of peach twig borer males when sprayed over a large area.

“So it turns out that during the mating season, females become good synthetic chemists,” Grubbs explained. “And she makes very precisely one complicated compound. And that’s called a pheromone. Each insect species has its own special pheromone.

“And the male becomes a really good analytical chemist, and they can detect chemicals at very low concentrations. And so given a concentration, the male hones in on the females, and they mate and lay eggs inside fruit, which causes problems.”

Grubbs explained that the solution is to blanket an entire field with the pheromone so that males cannot locate any specific females with which they can mate.

“This confuses the males,” Grubbs explained. “There’s a concentration gradient everywhere.”

A different kind of problem that Grubbs has approached more recently is cataract surgery. Around half of all cataract-surgery patients are required to wear corrective glasses after their surgery, and scientists and engineers have been looking for improvements or alternatives to this process, according to Grubbs.

Grubbs and his group at Caltech created a material for the synthetic lenses applied in cataract surgery that would allow for doctors to change the refracting power of the lenses after surgery, as opposed to having the patient resort to glasses.

“And according to the people in the know, this is working better than Lasik,” Grubbs said.

Leah Krainz, ’18, a biology major, attended the Lecture to see examples of how the material that she is learning in her chemistry classes can apply towards utilitarian, real-world advances.

“It is inspiring to see how [Grubbs’] work carried over to so many different fields of science and engineering,” said Krainz. “He was definitely very accessible. People should keep their eyes open for similar talks.”

Although Grubbs spoke on topics within the discipline of organic chemistry, the audience was filled with non-chemist students and faculty. Chris Yesukevich, ’18, found the Lecture to be far more accessible than he had anticipated.

“I appreciate that [Dr. Grubbs] is a different kind of speaker than those who we usually see at Allegheny,” said Yesukevich. “We don’t often get to hear from Nobel Laureates.”