Synthesis and absorption/emission properties of novel poly(silylenearylenevinylene)s

Abstract

AbstractPolymerization of p‐(dimethylsilyl)phenylacetylene in toluene at 25 and 80 °C with RhI(PPh3)3 catalyst afforded highly regio‐ and stereoregular poly(dimethylsilylene‐1,4‐phenylenevinylene)s [cis‐ and trans‐poly(1a)s] containing 98% cis‐ and 99% trans‐vinylene moieties, respectively. The trans‐type polymers exhibited redshifts and hyperchromic effects in the ultraviolet–visible spectrum as compared with the cis‐type counterparts. Photoirradiation of cis‐ and trans‐poly(1a)s gave cis‐rich mixtures at equilibrium states. The trans and cis polymers exhibited different emission properties, for example—trans polymer, emissn λmax = 400 nm, quantum yield: 3.4 × 10−3 and cis polymer, emissn λmax = 380 nm, quantum yield: 1.5 × 10−3. Besides poly(1a), poly(dimethylsilylenearylenevinylene)s containing biphenylene and phenylenesilylenephenylene units [poly(3)] were prepared. The extent of conjugation in these polymers decreased in the orders of biphenylene > phenylene > phenylenesilylenephenylene as well as trans‐vinylene > cis‐vinylene. The quantum yield of the trans‐rich polymer with biphenylene moiety was fairly large and 0.15. Polyaddition of 1,4‐bis(dimethylsilyl)benzene and three types of diethynylarenes (4,4′‐diethynylbiphenyl, 2,7‐diethynylfluorene, and 2,6‐diethynylnaphthalene) catalyzed by RhI(PPh3)3 provided novel regio‐ and stereoregular polymers [poly(6)]. These polymers displayed blue light emission with high quantum yields (4–81%). © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3615–3624, 2003