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Gregory H. Robinson calls himself a “card-carrying chemist guy,” but he sure doesn’t fit the stereotype. A former linebacker at Alabama’s Jacksonville State University and a stocky 6-feet-2, Robinson is an imposing figure. He plays an aggressive serve-and-volley brand of tennis, brews gourmet espresso in his office and brags that his youngest son, 4-year-old Alex, can rattle off the group I and II elements by heart. And when an experiment in Dad’s lab yields an exciting find, the two may even get the giggles. The giggles.
Ask Robinson about his work, however, and he’s all business. The Franklin Professor of chemistry at UGA studies organometallics, which are compounds that contain a carbon-metal bond. When he started his first lab in 1985, Robinson narrowed his focus to gallium, a silvery white oddly mercurial metal used in semiconductors. Two decades later, his pointed gaze has opened new horizons in the field by expanding chemists’ understanding of aromaticity — a chemical property that, despite its name, has little do with aroma and more to do with the stability of molecules in which electrons are free to cycle around circular arrangements, or rings, of atoms.
“Of all the concepts throughout chemistry,” Robinson said, “aromaticity is the most compelling,” in part because of his 1995 landmark paper on gallium’s aromatic properties. Earlier, scientists had maintained that only carbon-based organic compounds possessed such properties. Today, an entirely new field — metalloaromaticity — devoted to studying the ability of metals to take on aromatic properties has begun to take shape.
Aromatic compounds are stable because the ring-shaped molecule as a whole is not very reactive: at least part of the time each free electron is in a double-bond state [see picture]. “The concept that metals can form these same kinds of bonds [as organics] is very intriguing because it opens up all sorts of possibilities for more stable metal compounds,” Robinson said. One potential benefit could be better materials for semiconductors — an idea unheard of before the era of metalloaromaticity.
“We’ve come to realize that many of those formal barriers between organic chemistry and inorganic chemistry are largely a matter of semantics,” said Robinson.
His gallium research did not end in 1995. He and his team at UGA announced in June 1997 that they’d synthesized a compound with a gallium-gallium triple bond between atoms. And only four months later the group made another startling announcement — the development of a new way to bond iron and gallium, in a compound that also contained a triple bond.
These discoveries, which sparked intense debate in chemistry circles, were later confirmed by independent research groups, but the experience gave Robinson a lesson in the importance of perseverance — hanging in there when you believe you’re right — and the need to own up to mistakes. “Being a better scientist is a constant quest for everybody,” Robinson said. “I think I’m improving, and I hope I’ll always continue to improve.”
People in his lab certainly second that emotion, and they attest to Robinson’s continual growth. “He really enjoys the chemistry and always wants to go to that next level,” said Brandon Quillian, who joined Robinson’s lab at as a doctoral student two years ago.
Quillian and other team members are now working on a number of projects designed to probe the concepts of aromaticity, part of a five-year, $2.5 million National Science Foundation grant to a group of UGA chemistry faculty. Others on the grant include professors R. Bruce King, Henry F. Schaeffer III, Paul von Ragué Schleyer and Peter R. Schreiner.
As part of “that next level,” Robinson is now looking at aromatic properties in other metals, including zinc. This search for new knowledge in a wide-open field can be frustrating, but yet he persists. And sometimes, on a good day in the lab, his work even gives him the giggles.
For more information, contact Gregory Robinson at firstname.lastname@example.org.
THE UNIVERSITY OF GEORGIA RESEARCH MAGAZINE : www.researchmagazine.uga.edu