Research in organometallic chemistry involves using transition metals to manipulate the chemical bonds of organic molecules in order to transform the organics into higher value products. David Vicic employs a mix of focused exploratory chemistry, catalyst screening, and computational studies, to unravel how different metal/scaffold platforms could be used to either improve known reactions or carry out their own unique transformations.
Many modern processes used to make industrially important molecules employ rare and expensive metal catalysts like palladium and rhodium. Vicic, professor of chemistry, is trying to understand how to control the reactivity of more earth abundant and environmentally benign metals like copper, nickel, and iron in order to carry out similar transformations.
“The price of rhodium is about 600 times more expensive than nickel and far more compared to iron, so there is big motivation for learning how to control the reactivity of base metals.”
“The price of rhodium is about 600 times more expensive than nickel and far more compared to iron,” Vicic notes, “so there is big motivation for learning how to control the reactivity of base metals.”
A metal-mediated transformation of particular interest to the Vicic lab involves replacing certain hydrogens in organic molecules with fluorine. Fluorination can increase the chemical and thermal stability of organic molecules.
“The Teflon surface of a non-stick frying pan is largely fluorinated, as are special gaskets and seals that could withstand corrosive conditions.”
Vicic adds that fluorination is also important to the drug industry. “Pharmaceutical companies have an interest because they can replace some hydrogen atoms in drugs with fluorine to make them last longer in the body so they can get to their targets without decomposing.”
The stabilizing properties of fluorine, however, can also be a hindrance when it comes to developing new ways to prepare organofluorines, because fluorine also makes the metal catalyst super stable and less reactive, says Vicic. “Many of the metal-catalyzed transformations that happen with normal organic substrates are slow with fluorinated ones. We’re trying to figure out why and what we can do to the metal environment to improve catalysis.”
In this vein for his DOE-funded research, the Vicic lab has been preparing well-defined fluorine- containing organometallic complexes in order to see how they can be coaxed into targeted reactivity patterns.