Photoinduced electron transfer in silylene-spaced copolymers having alternating donor-acceptor chromophores

Silylene-spaced copolymers with alternating azacrown and anthracene moieties were synthesized for photoinduced electron transfer investigations. These polymers exhibited efficient intrachain photoinduced electron transfer with charge separation yield about 0.96-0.99 and corresponding charge-transfer rates around 10.8-32.2 ns(-1) in different solvents. Metal cations have been shown to enhance the fluorescence intensity due to complexation. These results are comparable to those of small molecules having similar chromophores. The geminal dimethyl substituents on silicon in these copolymers may direct the relative conformation (or distance) of the remaining substituents on silicon. Intrachain interactions between these chromophores may readily take place leading to highly efficient electron transfer processes.