Self-assembly of synthetic zinc chlorins in aqueous microheterogeneous media to an artificial supramolecular light-harvesting device

Self-assembled aggregates of a synthetic zinc chlorin in an aqueous suspens ion with either alpha-lecithin or Triton X-100 exhibit unique structural an d functional properties. Absorption, circular dichroism, fluorescence, and resonance Raman spectra indicate that the supramolecular structure in an aq ueous microheterogeneous medium is very similar to that of the bacteriochlo rophyll c aggregates in non-polar organic solvents and in chlorosomes, the main light-harvesting antennae of green photosynthetic bacteria. The nature of the aggregates is controlled by structure and/or concentration of the a dded surfactants. When a small amount of metal-free bacteriochlorin is pres ent it acts as an efficient energy acceptor from the aggregated zinc chlori ns. Thus, self-assembly of synthetic zinc chlorins, doped with appropriate energy accepters and surrounded with surfactants, affords an artificial sup ramolecular light-harvesting device in aqueous environment.