Mechanism of charge transport by redox metal complexes confined in polymermatrices

The mechanism of charge transport by metal complexes confined in polymer ma trices is reviewed. There are two possibilities, one where the charge propa gates in the matrix by diffusion of redox center molecules, and the other w here the charge propagates by hopping between redox center molecules. The m echanism can be decided by investigating the dependence of the charge propa gation rate on the redox center concentration, since in the diffusion mecha nism the rate is first-order with respect to the concentration, while in th e hopping mechanism it is second-order. In the hopping mechanism the charge -hopping distance can be analyzed by assuming a random distribution of the redox center in the matrix. The mechanism of charge transport by typical re dox centers such as metal porphyrins, metal phthalocyanines, Ru(bpy)(3)(2+) and methylviologen confined in a polymer membrane is presented and the cha rge-hopping distance is determined. Copyright (C) 2000 John Wiley & Sons, L td.