RUI: Photochemistry and Photophysics of Macrocyclic Chromium(III) Complexes: An Investigation of Electronic Energy Self-Exchange

Furman University, Greenville SC

Investigators

Abstract

This RUI award in the Inorganic, Bioinorganic and Organometallic Chemistry program supports Professor Paul S. Wagenknecht at Furman University to develop a better understanding of energy transfer between like species and the effect of thermodynamics on nearly thermoneutral energy transfer reactions. Systems such as trans- [Cr(N4)(CN)2]+ complexes (where N4 = a tetraazamacrocylic ligand), in which the thermoneutral energy transfers may be at least an order of magnitude faster than either of their endothermic or exothermic counterparts, will be studied. New macrocyclic Cr(III) complexes (some with tunable excited state properties) of several types will be prepared and utilized in energy transfer studies to answer the following questions: How narrow is the energy region over which this spike in rate occurs? How general is this phenomenon? What is the explanation for the accelerated rate in the thermoneutral case? In place of the cyanide ligand, substituted phenylacetylide ligands will be employed so that the photobehavior can be tuned via substitutions on the phenylacetylide. The new complexes will be characterized as to their photophysics and energy transfer properties by using pulsed-laser excitation and Stern-Volmer analyses. This project will provide fundamental data relevant to the field of alternative energy sources and will involve undergraduates in basic photochemical research.