Synthesis of silylene-phenylene and silylene-thienylene copolymers and their optical properties

Silylene-phenylene and silylene-thienylene copolymers were prepared by the reactions of α,ω-dichloropermethylated oligosilanes with 1,4-dilithiobenzene and 2,5-dilithiothiophene respectively. All the copolymers were soluble in a wide range of organic solvents. The influence of the chain length of the dimethylsilylene unit in the copolymer backbone on the electronic absorption spectra was investigated. The enhancement of σ-π conjugations between the dimethylsilylene units and the π-conjugated units with increasing dimethylsilylene chain length was suggested by the thermochromism.