The catalyst in this study is just a prototype for all the other molecules that the chemists hope to make, said co-author and professor of chemistry T.V. RajanBabu.
"Eventually, we want to make catalysts for many other reactions using the fundamental principles we unearthed here," RajanBabu said.
For this study, Parquette, RajanBabu, and postdoctoral researcher Jianfeng Yu synthesized batches of a hydrogenation catalyst in the lab and coaxed the molecules to change shape.
The technique that the chemists developed amounts to nudging certain atoms on the periphery of the catalyst molecule in just the right way to initiate a change in shape. The change propagates to a key chemical bond in the middle of the molecule. That bond swings like a hinge, to initiate a twist in one particular direction that spreads throughout the rest of the molecule.
Parquette offered a concrete analogy for the effect.
"Think of the Radio City Rockettes dance line. The first Rockette kicks her leg in one direction, and the rest of them kick the same leg in the same direction -- all the way down the line. A change in shape that starts at one end of a molecule will propagate smoothly all the way to the other end."
In tests, the chemists caused the catalysts to twist one way or the other, either to form one chemical product or its mirror image. They confirmed the shape of the molecules at each step using techniques such as nuclear magnetic resonance spectroscopy.
That's what the Ohio State chemists find most exciting: the molecule does not maintain only one shape. Depending on its surroundings -- the chemical "nudges" that it receives on the outside -- it will adjust.
"For many chemical reactions to work, molecules must be able to fit a catalyst like a hand fits a glove," RajanBabu said. "Our synthetic molecules are special because they're flexible. It doesn't matter if the hand is a smal
|Contact: Jonathan Parquette|
Ohio State University