Incorporation of π-conjugated polymer into silica:: Preparation of poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene]/silica and poly(3-hexylthiophene)/silica composites

The Wittig reaction of 2-methoxy-5-(2-ethylhexyloxy)-p-xylylenebis(triphenylphosphonium chloride) with 2-methoxy-5-(2-ethylhexyloxy)benzene-1,4-dicarbaldehyde was carried out to obtain poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinyleneI (MEH-PPV) terminated with a phosphonium moiety at the chain end. Poly[3-hexylthiophene-co-3-(6-hydroxyhexyl)thiophenels were prepared by regioselective coupling reaction of 2-bromo-3-hexylthiophene and 2-bromo-3-(6-(2-tetrahydropyranyloxy)hexyl)thiophene and subsequent cleavage of a tetrahydropyranyl group. Acid-catalyzed polycondensations of tetraethoxysilane (TEOS) were carried out in the presence of these polymers to give homogeneous composites with silica. The resulting composite materials were characterized by UV-vis and emission spectra.