The phenomenon of enhanced acidity occurring in the excited state of hydroxyarenes will be studied. Through strategic design and directed synthesis, new molecules with specifically designed internal proton acceptors or with greatly enhanced photoacidity have been prepared and will be studied. These substrates will allow the testing of various theories of exited state proton transfer, provide new methods of studies of proton transfer initiated reactions, and yield novel structures unattainable by ground state methods. These studies will involve molecular orbital calculations, organic synthesis of target molecules, time-resolved nanosecond fluorescence and other spectroscopic techniques, and structure analysis. %%% This grant from the Organic Dynamics Program supports the continuing work of Professor Laren M. Tolbert at Georgia Tech University. One of the important properties of organic molecules is their acidity, that is, how readily a proton can be transferred to a substrate. Proton transfers are important in the catalysis of many reactions and this is one of the reasons for the great interest in the acidity of organic molecules. Molecules that are excited by irradiation with ultraviolet light may display enhanced acidity, compared to their acidity in the absence of irradiation. The origin of this effect is not well understood and previous explanations may be in error. In the present study, molecules will be specifically designed to test various theories of proton transfer from molecules that are excited by ultraviolet light irradiation.
