Electron acceptors of the fluorene series. Part 6.1 Synthesis of 4,5-dinitro-9-X-fluorene-2,7-disulfonic acid derivatives, their charge transfer complexes with anthracene and sensitization of photoconductivity of poly-N-(2,3-epoxypropyl)carbazole

Abstract

Proceeding from fluorene-2,7-disulfonyl dichloride, a number of novel fluorene electron acceptors with sulfonyl substituents have been synthesized. Formation of charge transfer complexes (CTCs) of the synthesized acceptors with anthracene in dichloroethane has been studied by appearance of long-wavelength CTC bands in the visible region of electron absorption spectra. The values of equilibrium constants determined for three acceptors (i.e. 18, 22a, 22b) show that the process of CTC formation is affected both by electronic and steric factors. Sensitization of poly-N-(2,3-epoxypropyl)carbazole (PEPC) photoconductivity with compounds 18, 21a and 22a has been studied.