Synthesis and Properties of Substituted Polyacetylenes Containing Pyrene Moieties in the Side Group

Abstract

A novel phenylacetylene derivative containing a pyrene group was synthesized and polymerized with various Rh complex catalysts. The obtained polymers were soluble in common organic solvents such as chloroform and THF. The Mw and Mw/Mn were estimated as ca. 12000–18000 and 1.3–1.7 respectively, and the polymer yields were estimated as around 57–72%. The characteristic absorptions of ≡C–H (3200 cm−1) and C≡C (2100 cm−1) stretchings seen in the monomer spectra have completely disappeared in the polymer spectra from IR spectrum. 1H NMR analysis confirmed that the acetylene triple bonds transformed to polyene double bonds. These polymers were found to be thermally stable based on TGA data. The synthesized polymers exhibited blue fluorescence. The fluorescence quantum yield in solution was high at 0.37–0.41. Furthermore, the obtained polymer had a long fluorescence lifetime.

Rhodium-Catalyzed Stitching Polymerization of Alkynylsilylacetylenes

“…Rhodium-catalyzed polymerization of terminal alkynes such as phenylacetylene is one of the well explored chain polymerizations to give π-conjugated polymers (Scheme a) . In addition to the development of highly effective catalyst systems as well as the detailed studies on the polymerization mechanism, applications toward functional materials possessing various properties such as helix-induced chirality, fluorescent characteristics, liquid crystallinity, and gas permeability have also been actively investigated through introduction of appropriately functionalized substituents to the monomers. However, only carbon-substituted alkynes have been employed as monomers to date, and the reported polymerization patterns were either simple coordination–insertion of monoynes or cyclopolymerization of diynes until recently, which significantly limited the accessible structures of the main chain repeating unit.…”