RAFT synthesis of linear and star-shaped light harvesting polymers using di- and hexafunctional ruthenium polypyridine reagents

The syntheses of linear and star-shaped light harvesting polymers with well defined structure and narrow molecular weight distribution are described. These polymers have ruthenium polybipyridine moieties as the energy trap cores and styrene functionalized coumarin monomers as the light absorbing antenna chromophores. The polymers have been made by reversible addition-fragmentation chain transfer (RAFT) polymerisation using di- or hexafunctional ruthenium-containing RAFT agents. The resulting ruthenium-containing polymers have narrow molecular weight distribution (polydispersity < 1.1) and exhibit energy transfer efficiencies of up to 60% between the coumarin donor dyes and the ruthenium acceptor chromophores.