Unsaturated Polycarbosilane Synthesis, Characterization And Fluorescent Properties

Polycarbosilanes have a wide variety of applications in the fields of semiconductor materials, chromophores, ceramic precursors, fire retardants, and hybrid elastomeric components, because of their important physical and chemical properties, such as thermal stability, solubility, processability and low toxicity, which makes the studies on syntheses, structural characterization, and structure-property relationship of functional polycarbosilianes one of valuable research topics. Hydrosilylation reaction is very mild and can tolerate many functional groups in reactants, such as ester, nitriles, amines, amides, nitro, ether etc., becoming an efficient method to construct functional silicon-containing polymers.In this paper, we synthesized three dimethylsilylated monomers, 1,4-Bis(dimethylsilyl)benzene,4,4'-bis(dimethylsilyl)biphenyl,9,10-bis(dimethylsilyl)anthracene. The reactions of these compounds with 4,4'-bis(phenylethynyl)biphenyl using RhCl(PPh3)3/NaI as catalyst through hydrosilylation resulted in corresponding unsaturated polycarbosilane. Results of structural characterization of addition products showed good region- and stereoselectivity and most of double bond in the polymer chain is preferred for theβ-E-type.Further studies on photophysical properties of polymer found that polymer 1 and polymer 3 can conduct energy transfer. We also use p-nitroaniline to study polymer's fluorescence quenching.