UNIVERSITY PARK, Pa. -- Mark Maroncelli, professor of chemistry at Penn State, has won the American Chemical Society’s Joel Henry Hildebrand Award in the Theoretical and Experimental Chemistry of Liquids. Maroncelli will receive this award in recognition of his distinguished contributions to the understanding of the chemistry and physics of liquids in a ceremony next year at the 249th annual meeting of the American Chemical Society in Denver. The award is sponsored by ExxonMobil Research and Engineering.

Maroncelli’s research seeks to develop a fundamental understanding of the molecular nature of solvation and how it affects chemical reactions taking place in solution. Solvation involves the interactions between dissolved molecules (solutes) and molecules of the solvent. Favorable arrangements of solvent molecules around the solute molecules lower the energy of the solute, which leads to dissolution. The interactions involved are typically very rapid, taking place in as short a time as 1 picosecond (1 trillionth of a second).

Because the key steps in most chemical reactions also occur on these fast time scales, time-dependent aspects of solvation partly determine if a solvent will alter the rate and course of chemical reactions. Maroncelli uses ultrafast-spectroscopic techniques in combination with modern computational-chemistry methods to observe, analyze, and predict the solvation process and its impact on the chemical steps that occur during the particular reaction being investigated.

Maroncelli’s recent research has explored the nature of solvation in novel solvents such as supercritical fluids, gas-expanded liquids and ionic liquids. Comparing model reactions such as isomerization, electron transfer and proton transfer in these novel solvents with such reactions in conventional liquids enables the research team to test and extend the current understanding of solvent-reaction coupling. These studies have potential applications in technical chemistry, synthetic chemistry and cell biology.

Maroncelli was honored with a Humbolt Research Award for Senior U. S. Scientists from the Alexander von Humboldt Foundation in Bonn, Germany, in 2010. He was named a Fellow of the American Association for the Advancement of Science in 2008. Maroncelli received a Guggenheim Fellowship in 2001.

A member of the Penn State faculty since 1987, Maroncelli was named associate professor in 1993 and professor in 1997. Before he arrived at Penn State, he was a postdoctoral researcher at the University of Chicago from 1985 to 1987 and at Oregon State University from 1984 to 1985. He earned a doctoral degree in chemistry at the University of California at Berkeley in 1983 and a bachelor’s degree in chemistry, with highest honors, at Williams College in 1979.