1. Probing Photocatalysis Reaction Dynamics and Mechanism Using Non-equilibrium Multidimensional Infrared Spectroscopy
Kevin J. Kubarych, Department of Chemistry, University of Michigan
Using novel transient 2DIR methods, we have observed chemical reactions in solution with ultrafast resolution and structural sensitivity. Reactions at equilibrium are probed using 2DIR chemical exchange spectroscopy, where new cross peaks grow in as products and reactants swap identities. Transient photoproducts can be monitored using 2DIR spectroscopy as a probe. New spectral features change in shape and intensity as the reaction progresses, or as the photoproduct cools. Transient 2DIR can illuminate vibrational relaxation, energy transfer, coupling, orientational relaxation, and dynamic inhomogeneity, in non-equilibrium molecules undergoing or immediately after a chemical reaction.
exchange
Ultrafast chemical exchange between structural isomers of Co2(CO)8 in n-hexane solution
Transient 2DIR shows the Mn(CO)5 photoproduct (red) 80 ps following 400-nm photolysis of Mn2(CO)10 in cyclohexane solution