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-ph enylenevinylene have been prepared by the Wittig reaction between the diphosphonium salt of 2,6-bis(chloromethyl) pyridine and terephthaldeh yde or 2,5-dialkoxpterephthaldehydes. The protonation reaction of ly(1 ,4-phenylenevinylene)-co-(2,6-pyridylvinylene) with hydrochloric acid and the quaternization reaction of poly(2,5-dioctyloxy-1, 4-phenylenev inylene)-co-(2,6-pyridylvinylene) with methyl triflate have been inves tigated by spectrophotometric and fluorescent methods. The absorption, excitation and fluorescence spectra of these copolymers as well as th eir corresponding model compounds were studied and compared. The photo physical properties of the investigated polymers suggest that these ma terials could be good candidates for the fabrication of efficient blue light-emitting diodes. (C) 1997 Elsevier Science S.A.