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Chemistry Seminars

October 24, 2013
Smith Hall,
Room 114, 12:30 p.m.

*Pre-seminar reception at 12:15 p.m.

Ben Lear

Department of Chemistry, Penn State University
University Park, PA

Nanoscale Heat as a New Tool for Chemists

Heat is a familiar tool in synthetic chemistry, used to overcome the barrier that separates products from reactants. Despite the near ubiquity of this tool, it is often poorly matched to the scale of chemical processes. Most of the chemicals used in synthetic chemistry are on the order of nanometers or less, and the transition along the reaction coordinate takes on the order of picoseconds. Thus, the common procedure of refluxing a reaction mixture in a flask results in the application of heat on a scale ten orders of magnitude larger than the chemical system, and for a time 14 orders of magnitude longer than needed for the reaction.

We are working to use the photothermal effect of nanoparticles to develop a new approach to driving thermal reactions -- one that provides heat better matched to the reactants and products. Nanoparticles are able to provide extreme temperatures (> 800 K) with nanometer and nanosecond precision. In this talk, I will discuss work in our lab that seeks to determine the chemical effects of this heat, demonstrate the generality of this approach for performing useful chemistry, and identify unique applications that are only possible using this level of control over applied heat.