Synthesis and efficient energy transfer in a three-chromophore energy gradient of regioregular silylene-spaced divinylarene copolymers

Regioregular silylene-spaced copolymers 1 composed of an energy gradient with three different chromophores have been achieved by rhodium-catalyzed hydrosilylation of bis-vinylsilanes 3 and bis-alkynes 4. Monomeric reference compounds 2 were prepared for comparison. The ratio of three chromophores is 1:2:1, corresponding to D₁, D₂, and A chromophores, respectively. The dimethylsilylene (SiMe₂) moiety serves as an insulating bridge between chromophores. Upon excitation of the donor chromophore (D₁), only emission from the acceptor (A) was observed. Efficient and sequential energy transfer across three different chromophores along the polymeric backbone may proceed smoothly in these silylene-spaced copolymers.