Copolymers with fragments of meta-pyridylvinylene and para-phenylenevinylene: synthesis, quaternization reaction and photophysical properties

Conjugated copolymers with fragments of 2,6-pyridylvinylene and 1,4-phenylenevinylene have been prepared by the Wittig reaction between the diphosphonium salt of 2,6-bis(chloromethyl)pyridine and terephthaldehyde or 2,5-dialkoxyterephthaldehydes. The protonation reaction of poly(1,4-phenylenevinylene)-co-(2,6-pyridylvinylene) with hydrochloric acid and the quaternization reaction of poly(2,5-dioctyloxy-1,4-phenylenevinylene)-co-(2,6-pyridylvinylene) with methyl triflate have been investigated by spectrophotometric and fluorescent methods. The absorption, excitation and fluorescence spectra of these copolymers as well as their corresponding model compounds were studied and compared. The photophysical properties of the investigated polymers suggest that these materials could be good candidates for the fabrication of efficient blue light-emitting diodes.