HOLE INJECTION AND FORMATION OF POLARONS IN CYCLOALKANE LIQUIDS

In several cycloalkanes, ionization of the solvent or photoexcitation of a solute radical cation results in the formation of rapidly hopping solvent holes. Here we report the temperature dependence of scavengin g rate constants and conductivity signals (220 to 350 K) for the solve nt holes in liquid cyclohexane, methylcyclohexane, and Decalins. Our r esults indicate that the hopping in Decalins and methylcyclohexane is thermally activated; the activation energies are of the same order as the energy of solvent reorganization. In cyclohexane, the hopping does not seem to be thermally activated. We discuss the hypothesis that th e mobile solvent holes in cycloalkanes are small polarons migrating by phonon-assisted hopping.