Light-emitting conjugated molecule containing 1,3,4-oxadiazole, carbazole and naphthalene units

A novel pi-conjugated small molecule VNCO, 2,5-bis{3'-[3"-vinyl-9"-(u-naphthyl)carbazolyllphenyl}-1,3,4-oxadiazole, containing qholetransporting carbazole moieties, electron-injecting 1,3,4-oxadiazole moieties and chromophore naphthalene was designed and synthesized by Wittig reaction of 2,5-bis(3-tolytene-triphenylphosphonium bromide)- 1,3,4-oxadiazole and 3-formyl-9-(alpha-naphthyl)carbazole. The UV-vis absorption, fluorescence excitation and emission spectra have been obtained in solution for VNCO. The photoluminescence (PL) of VNCO were examined in different solvents and the luminescence quantum yield was 0.746 in chloroform. It emitted blue and blue-green light, with the band gap of 3.30 eV estimated from the onset absorption. In addition, the light-emitting can be quenched by both electron donor (N,N-dimethylaniline) and electron acceptor (dimethylterephalate). Furthermore, the molecular interactions of VNCO with fullerene (C-60) or carbon nanotubes (CNTs) were also carefully investigated. (c) 2005 Elsevier B.V. All rights reserved.