Precursor route chemistry and optoelectronic properties of poly(pyridine vinylene)

Several soluble precursor routes, involving sulfonium-, methoxy-, and chloro-substituted polymers, have been investigated for the synthesis of poly(pyridine vinylene) (PPyV). The thermal conversions of these precursors to fully conjugated polymer PPyV have been characterised by TGA, FT-IR and UV-VIS spectroscopy in conjunction with microanalysis. Of all the precursors, the chloro-substituted polymer is the most convenient for forming good quality thin films. PPyV fluoresces orange red and has a HOMO-LUMO band gap of 2.2 eV. PPyV has a lower luminescent quantum efficiency compared with its analogue, poly(phenylene vinylene) (PPV), but a higher electron affinity according to CV measurements (with reduction potential of −1.3 V). PPyV was used as an orange red emissive layer in a LED using aluminium as cathode.