PHOTOINDUCED ELECTRON-TRANSFER IN SUPRAMOLECULAR ASSEMBLIES OF TRANSITION-METAL COMPLEXES

Photoinduced electron transfer in supramolecular assemblies consisting of pi-donor dialkoxyarene-functionalized photosensitizers and bipyrid inium electron accepters is examined. The photosensitizers include Ru( II)-tris-bipyridine complexes tethered by multi-branch one-shell and t wo-shell dialkoxybenzene pi-donor sites or a Zn(II)-porphyrin capped b y a dialkoxybenzene receptor site. The photosensitizer/electron-accept or supramolecular complexes behave as non-covalent diads and polyads. Effective internal electron transfer quenching within the supramolecul ar assemblies proceeds. A quantitative model that accounts for the pho toinduced electron transfer in the systems is formulated. (C) 1998 Els evier Science S.A.