Biology Department Seminar

Artificial photosynthesis is an area of research that seeks to replicate the natural process of photosynthesis that coverts sunlight, water and carbon dioxide into carbohydrates and oxygen. The visible-light driven splitting of water into hydrogen and oxygen and even the targeting of methanol as the product of CO2 reduction are sometimes included in the definition. There are two distinct approaches to realizing the goal of artificial photosynthesis: structural models vs. functional models of the natural systems. We are pursuing functional models as exemplified in recent work on hydrogenase-inspired catalysts for H2 oxidation and proton reduction.1,2 The function of the chlorophyll arrays in plants might be replaced with a suitable band-gap-narrowed semiconductor photoanode3 in an electrochemical cell, possibly with the aid of a molecular multi-electron water oxidation catalyst.4,5 The role of the NADH co-factor as the carrier and donor of two electrons and a proton might be replaced by a photogenerated hydride donor6,7 to carry out the function of Photosystem I. Examples from our current work in these areas will be presented. 1. A.D. Wilson, R.H. Newell, M.J. McNevin, J.T. Muckerman, M.R. DuBois, and D.L. DuBois, J. Am. Chem. Soc. 128, 358 (2006). 2. A.D. Wilson, R.K. Shoemaker, A. Miedaner, J.T. Muckerman, D.L. DuBois, and M.R. DuBois, PNAS USA 104, 6951 (2007). 3. L.L. Jensen, J.T. Muckerman, and M.D. Newton, J. Phys. Chem. C, in press (2007). 4. T. Wada, K. Tsuge, and K. Tanaka, Inorg. Chem. 40, 329 (2001). 5. J.T. Muckerman, D.E. Polyansky, T. Wada, K. Tanaka, and E. Fujita, Inorg. Chem., in press (2007). 6. D. Polyansky, D. Cabelli, J.T. Muckerman, E. Fujita, T. Koizumi, T. Fukushima, T. Wada, and K. Tanaka, Angew. Chem. Int. Ed. 46, 4169 (2007). 7. D.E. Polyansky, D. Cabelli, J.T. Muckerman, T. Fukushima, K. Tanaka, and E. Fujita, Inorg. Chem., submitted (2007).