The synthesis of robust, polymeric hole-transport materials from oligoarylamine substituted styrenes

Novel styrene-based oligoarylamine monomers are described which are suitable for the preparation of polymeric hole-transport materials, with very high glass transition temperatures. The monomers are prepared using the Wittig reaction from the appropriate aldehyde precursor, which was assembled using the classical Ullmann reaction. A number of the monomers yielded high-quality crystals which facilitated X-ray characterisation. Polymerisation was achieved either by solution free-radical initiation or by condensed phase thermal autopolymerisation. The latter suggests a method of initiator-free polymerisation which may have potential for multilayer device fabrication.