Synthesis and electrooptical characterization of polysiloxanes containing indolyl groups acting as photoconductive substrates for photorefractive materials

Synthesis and electrooptical analysis of polysiloxane and poly-N-vinyl derivatives containing indolyl groups are reported. The indole group and some of its methyl derivatives have been taken into account in order to evaluate their behaviour, with respect to that of the widely employed carbazole group, when used as photoconductive centres attached to a polymer chain. The obtained data show that photoconductivity and traps formation mechanism can be inferred as functions of the physico-chemical parameters (electric dipole moment and ionization potential) of the different groups and polymers involved. To this end such parameters have been carefully computed for a series of pyrrole, indole and carbazole derivatives. The 2,3-dimethylindole derivative appears to be particularly promising due to its electrooptical behaviour in the red absorption region where measurements have been accomplished and are shown to be consistent with the theoretical predictions.