March 5, 2013

Prof. Kyle Lancaster: Molecular Interrogator

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Bob Hackett ’12 was a senior writer for The Sun’s science section who came to Ithaca on the weekend of Feb. 16 to write a story.

Prof. Kyle Lancaster, chemistry and chemical biology, named one of 30 “rising stars tansforming science” by Forbes’ magazine last December, interrogates molecules for a living. So far, aged only 29, he’s been prodigiously successful.

“To paraphrase the movie Taken, I’ve spent a career developing a very particular set of skills,” Lancaster said. “Skills that make me dangerous to molecules, so they can’t hide their secrets from me.”

He is not an ex-CIA agent. He is a chemist … specifically, a spectroscopist: one who employs different types of light (“spectra”) to look at or observe (“-scopy”) matter.

“What we do is we probe these molecules with a whole bunch of different wavelengths of light,” Lancaster said, listing visible light, X-rays and microwaves. Each form of light can be used as a tool to reveal otherwise unseen or hidden molecular information. For instance, microwaves can help you see how many electrons are in different spin states, he said, and ultraviolet-visible photons may let you glimpse oxidation states, couplings and ligand field strengths.

“In our current efforts we’re using X-rays to see what types of atoms are bound to a transition metal,” Lancaster said. “We use a technique which is called K-Beta-X-ray emission spectroscopy and, specifically, we look at what is referred to as the ‘Valence to Core’ transitions, or ‘V2C.’”

The method is a violent one, he said. Essentially, his team bombards an atom with high-energy, high-intensity X-ray radiation until it rips an electron out of that atom’s lowest level orbital, where electrons are most tightly bound. To further illuminate the technique, he drew an analogy to people.

If you are going to try to get information out of someone there are several routes you can take, he said. You can butter someone up, take them out for a nice dinner, get them on your side and have them give you the information willingly. Or you can take the alternative.

Basically, grilling them until “eventually [the person or molecule] will tell us everything that we wanted to know, and some things that we didn’t,” he said. When it comes to chemistry, in the archetypal Good-cop/Bad-cop dichotomy, Lancaster assumes, by his own admission, the latter role.

Once the X-rays have stripped that critical electron from an atom, “[the atom] will do anything. It will sell out its own mother to get that electron hole refilled,” he said. Occasionally, the atom will do so by stealing an electron from a neighboring atom. This process emits a photon of a certain energy level which, when measured, may reveal important information about the atoms.

“One of the first people to use this for chemical applications,” he said, was Prof. Serena DeBeer, chemistry and chemical biology, Lancaster’s post-doctoral research advisor, under whom he studied before she transitioned to the Max Planck Institute in Muelhiem, Germany two years ago.

“That’s why I came here to work with her, to learn the technique,” Lancaster said.

Cornell is home to one of the very few facilities in the world that can achieve the intense photon energies needed to perform the kind of chemical interrogation that is Lancaster’s specialty. That facility, where waves of X-ray light collide with molecular matter, is the Cornell High-Energy Synchrotron Source, located beneath the Upper Alumni Athletic Field.

In a 2011 paper published in Science Magazine in which he was the lead author, Lancaster solved, along with principal architect of the study DeBeer and various collaborators, what Forbes’ reporter Matt Herper has described as “an old chemical puzzle” — “sort of the great outstanding question of bioinorganic chemistry,” Lancaster said.

For a decade, scientists had been trying to figure out the identity of the central atom in a very important molecule, a catalyst that has been responsible for the flourishing of life on this planet: nitrogenase. Since nitrogenase splits nitrogen gas to make ammonia, it seemed to make sense that the central atom, “Atom X,” might be nitrogen.

“That’s sort of the nice, feel good answer,” Lancaster said. Others, however, believed Atom X to be oxygen, especially since, within nitrogenase, it is coordinated to iron, a metal that often pairs with oxygen. Still others argued that the mystery atom did not exist at all, that its apparent presence was an artifact of the crystal structure. And yet another sect thought it might be carbon.

“That seemed fairly preposterous to people,” Lancaster said, referring to the carbon camp. “But it was still a possibility.”

The contest came to an end after the team published their results from the K-Beta-X-ray emission spectroscopy technique. Nitrogenase had succumbed. After rounds of brutal X-ray interrogation, the obstinate atom squealed, releasing tell-tale photons at an energy level of 7,100 electron volts, characteristic of only one element. Atom X: carbon, after all.

“It sort of cemented my place in the bioinorganic community,” he said, noting that his previous graduate study work and papers in copper and iridium also contributed. “I think it was a nice way of showing that I am a pretty serious business spectroscopist.”

Ironically, Lancaster’s field, bioinorganic chemistry, is characteristically defined by the absence of carbon-metal bonds.

“The organometallic community — that is to say, the folks who bind carbon to metals with regularity — were very amused to find out that the arguably most important cofactor in bioinorganic chemistry, which has sort of got a little sibling rivalry to organometallic chemistry, turned out to be an organometallic cofactor,” he said. “So now I guess I find myself as an organometallic chemist as a result.”

Having demonstrated with others that the technique can solve difficult problems, Lancaster is gearing up to continue tackling and understanding fundamental questions in chemical catalysis, such as: How can we build a better catalyst? How can we build one that produces less waste? That doesn’t rely on precious or toxic metals? And, how can we draw inspiration from biology, which achieves very difficult chemical transformations, when designing catalytic processes?

“The bottom line is that we’re interested in solving or understanding systems and solving problems that are relevant to minimizing the burden we place on this planet,” he said. “Transition metals have granted humans immense power to transform matter. And the ability to rationally control how they do so is really the grand challenge of inorganic chemistry in the 21st century.”

In addition to science, Lancaster used to D.J. in his spare time back in Southern California, where he grew up and attended school. In his lab, which is currently being assembled, he claims to have the best sound-system in S.T. Olin. He also enjoys red wine — Malbec, in particular, after recently spending time in Argentina, a country known for that varietal — which he drinks at wine hours on Friday’s with some colleagues in the chemistry department.

His advice to students now studying at the University, regardless of major, is that if you are doing what you love, things are going to pan out. Worked for him, he said.

Regarding his naming on the Forbes’ list, Lancaster said he“feels honored.” “I hope I can continue to deliver good science,” he added.

Original Author: Bob Hackett

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