Facile Preparation of Transparent, Homogeneous, Fluorescent Gel Film Based on σ−π-Conjugated, Hyperbranched Polymer with Siloxane Linkages by Means of Hydrosilylation and Aerial Oxidation

A new AB<INF>2</INF>-type monomer, m-bis[dimethylsilyl]phenylacetylene (<BO>2</BO>), was obtained by lithiation of m-dibromophenylacetylene followed by reaction with chlorodimethylsilane. Rh-catalyzed hydrosilylation and subsequent aerial oxidation of <BO>2</BO> provided a transparent gel film based on hyperbranched poly[(dimethylsilylene)(m-phenylene)(trans-vinylene)] (<BO>1</BO>) with siloxane linkages. The SEM and EDX analyses of the gel film revealed that the siloxane linkages were uniformly formed in the polymer matrix without any defects such as phase separation and decomposition. The gel film displayed a weak, but clear absorption in a wide range of wavelengths longer than 300 nm, due to the charge-transfer phenomenon. When excited at the charge-transfer absorption wavelength, the gel film emitted quite intense blue light that could be seen by the naked eye. The gel film showed excellent resistance against various organic solvents.