Photoinduced electronic energy transfer in a supramolecular complex between a coumarin bichromophoric molecule and lead(II)

A bichomophoric molecule consisting of two coumarins linked by a penta(ethylene oxide) spacer is able to bind cooperative three Pb2+ ions in propylene carbonate. In the ersulting supramolecular complex which is likely to be helical, the efficiency of energy transfer from the coumarin-donor to the coumarin-acceptor is 90% and the interchromophoric distance is about 14 Å.