WHAT LOWERS THE EFFICIENCY OF AN ENERGY TRANSFER REACTION BETWEEN PORPHYRIN DYES ON CLAY SURFACE?(TMC2010)

Abstract

Excited energy transfer reaction from tetrakis(1-methylpyridinium-2-yl) porphyrin (o-TMPyP) to tetrakis(1-methylpyridinium-4-yl) porphyrin (p-TMPyP) on an anionic clay surface was investigated. The energy transfer efficiency and quenching efficiency due to an electron transfer were quantitatively estimated. Both the energy transfer efficiency and quenching efficiency increased as the dye loadings increased. By a comparison with the results of other porphyrin combination systems, it was found that the major factor for lowering the energy transfer efficiency was the self-quenching of the donor porphyrin on the clay surface. Since the self-quenching was effectively suppressed by the strong adsorption of porphyrin on the clay surface due to the Size-Matching Effect, relatively efficient energy transfer was achieved. For constructing an efficient energy transfer system, such as an artificial light-harvesting system, a suppression of the self-quenching of dyes on the clay surface should be important.