Synthesis, light-harvesting and energy-transfer properties of regioregular silylene-spaced alternating [(donor-SiMe₂-)_n=1-3- (acceptor-SiMe₂)] copolymers

A series of silylene-spaced alternating [(donor-SiMe₂) _n=1-3-(acceptor-SiMe₂)] copolymers 4-6 was synthesized by rhodium-catalyzed hydrosilylation of bisalkynes with bissilyl hydrides. Monomeric reference compounds 7-10 with similar chromophore components were prepared for comparison. The ratio of donor to acceptor groups is well-controlled by the precise regiochemistry and nature of the repeat units. The silylene moieties serve as insulating spacers between chromophores. The polymers exhibit light-harvesting abilities, for which the intensity of the emission enhanced with larger donor-to-acceptor ratios. No emission originating from the donors was observed in fluorescence spectra, illustrating that intrachain energy transfer is highly efficient along the polymer chain.