Emitting oligomer containing quinoline group: Synthesis and photophysical properties of conjugated oligomer obtained by Wittig reaction

Dichloro quinoline substituted phenylene vinylene oligomer (QUI-OPV) was synthesized via Wittig route. Formation of the oligomer was characterized by spectral (FTIR, 1H and 13C NMR), elemental and gel permeation chromatography analysis. The oligomer possesses excellent thermal stability (decomposition temperature 470 °C), solubility in common organic solvents and high glass transition temperature (61 °C). The morphology of the oligomer film of one dimensional (1D) and three dimensional (3D) architectures was observed using atomic force microscopy (AFM). In CHCl3 solution, the oligomer showed the absorption maxima at 382 nm and also observed excellent photoluminescence (PL) with bluish green emission maxima at shorter wavelengths of 477 nm. The introduction of quinoline to the main chain resulted in a slight decrease of effective conjugation length and exhibited the blue shift in both the absorption and emission spectra.