Proposal: 9357130 PI: Therien Professor Michael Therien of the University of Pennsylvania is the recipient of this NSF young Investigator Award from the Inorganic, Bioinorganic, and Organometallic Chemistry Program. He has launched his career by developing a new synthetic strategy for preparing substituted porphyrins, by using the method to obtain a wide variety of donor-acceptor molecules based on porphyrins, and by using these molecules to explore the electronic coupling between the two centers. Under the present grant he will exploit these molecules in order to assess the relative importance of hole versus electron tunneling, to measure coupling through "weak" links such as hydrogen bonds, to probe the significance of quantum beats in ultrafast electron transfer, and to develop catalysts for alkane oxidation. %%% Reactions in which an electron transfers from one site to another are among the most intriguing, significant, and at the same time apparently simple that can occur in biological systems. In such systems electron transfer can take place over long distances, and then the intervening medium assumes an important role. By designing molecules in which electron transfer can be forced to flow through specified linkages, fundamental and general questions can be answered regarding the control that these linkages exert. Such molecules will be constructed on the basis of porphyrins, which are molecules that are widely found to participate in biological electron transfer. The results will illuminate the details of porphyrin chemistry, develop the theoretical understanding of electron transfer, and provide synthetic catalysts for industrially significant reactions.
