Synthesis of new hole-transporting molecular glass with pendant carbazolyl moieties

The synthesis and properties of amorphous hole-transporting 4,4′-bis[11-carbazol-9-yl)-6,8,10-tri(carbazol-9-methyl)-3-hydroxy-5,7,9-trioxa-1-thia]thiobisbenzene with two end and six pendant carbazolyl moieties, separated from the main chain by CH₂ spacers, is reported. It was prepared by a multistep synthesis route from 1,6-di(carbazol-9-yl)-5-(carbazol-9-methyl)-4-oxa-2-hexanol glycidyl ether. Glass transition temperatures of intermediate and final products established by differential scanning calorimetry are reported. The hole drift mobility, measured by the time of flight technique, in this well defined molecular glass depends little on the strength of the electric field and exceeds 10⁻⁵ cm² V⁻¹ s⁻¹. The ionization potentials measured by electron photoemission method, light absorption and fluorescence spectra are closed to those reported for the other organic photoconductors containing electronically isolated carbazole moieties.