Synthesis and photophysical study of unsymmetrical porphyrin pentamers

A dithiaporphyrin building block with an N2S2 core is synthesized and coupled with porphyrin building blocks with N4 cores to obtain an unsymmetrical pentamer. Steady-state fluorescence spectra indicated that there is an efficient energy transfer from an excited N4 porphyrin unit to an N2S2 porphyrin unit.