Mimicking the Photosynthetic Process in a Macromolecule

Significance

A wheel-shaped macromolecule, 1, comprised of five bis(phenylethynyl) anthracene antenna chromophores and a porphyrin-fullerene electron donor-acceptor moiety was synthesized and shown to demonstrate efficient light harvesting in the 430-480 nm spectral region, where solar irradiance is maximal. Singlet energy transfer from the five anthracene antennas of 1, which absorb strongly in the 430-475 nm region, to the porphyrin moiety occurs rapidly and with a quantum yield of ˜100%. Subsequently, photoinduced electron transfer creates a P ^{⟨ +}-C₆₀ ^{⟨ -} charge-separated state, thus mimicking the process used by photosynthetic organisms to convert sunlight into electrochemical potential. The details of the synthesis of the macromolecule are reported in a separate account: J. Porphyrins Phthalocyanines 2005, in press.