Synthesis and monolayer spreading behaviour of surface-active compounds containing electron- and hole-transporting groups. 1. Fluorenylidene derivatives

Abstract

Surface-active derivatives containing fluorenylidene groups were synthesized, with the goal of creating thin-film devices incorporating monolayers of electron-transporting materials. The new compounds were studied in monolayers at the air–water interface, and were further characterized by cyclic voltammetry. The spreading behaviour of long-chain esters of a fluorenylidene malononitrile carboxylic acid was relatively insensitive to the cross-sectional area of the hydrocarbon chain, but was more strongly affected by changes in the polarity of the hydrophilic groups. Conditions for Langmuir–Blodgett deposition of multilayers of two of the new compounds on titanium-coated polyester film were also explored. Keywords: monolayers, Langmuir–Blodgett films, fluorene, surfactants.