SINGLET SINGLET INTRAMOLECULAR ENERGY AND ELECTRON-TRANSFER IN COVALENTLY-LINKED PORPHYRIN PHTHALOCYANINE HETERODIMERS

Intramolecular transfer processes in porphyrin-phthalocyanine heterodimers covalently linked by an oxygen atom (restricted conformation) and/or by a flexible chain of variable length were investigated. Fluorescence spectroscopy shows that singlet-singlet energy transfer from the porphyrin to the phthalocyanine moiety occurs. From fluorescence decay studies, it is concluded that the heterodimers exist in solution in different non-equilibrating conformations. The effects of the chain length and mutual orientation of the chromophore subunits in the heterodimers on the intramolecular energy and electron transfer efficiencies are discussed.