Tailored amphiphilic star-shaped light-harvesting copolymers

Abstract

Amphiphilic star-shaped light-harvesting copolymers comprising six diblock arms of styryl coumarin (St-Coumarin) and N-isopropylacrylamide (NIPAM) surrounding a ruthenium(II) tris(bipyridyl) energy-trap core have been synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization. The mechanism of excitation energy transfer (EET) from initially excited St-Coumarin chromophores to the Ru(II) trap has been investigated and is concluded to occur mainly through a single-step induced dipole-dipole process. Incorporation of the NIPAM sequences results in enhanced EET efficiencies and confers water solubility to the polymers. The photophysical behavior of the copolymers is re..