HOLE DRIFT MOBILITY AND CHEMICAL-STRUCTURE OF CHARGE-TRANSPORTING HYDRAZONE COMPOUNDS

The hole drift mobility of several hydrazone compounds dispersed in a polymer binder was correlated with their chemical structure. The mobility of hydrazone compounds having the same basic skeleton, i.e., aminophenylhydrazone, varied over about two orders of magnitude by systematic change of the substituents on the N atoms. The variety of the hole mobility was discussed on the basis of the concept of polyfunctionality and intramolecular mobility. From molecular orbital calculations, the importance of the positive charge distribution on a molecule in the cation radical state was emphasized for the molecular design of high-mobility charge-transporting compounds.