Energy and electron transfer processes in self-organized porphyrin and chlorin triadic and pentadic complexes

摘要

Self-organized arrays stable at room temperature containing three or five macrocyclic fragments have been constructed using two-fold ligation of Zn-porphyrin and Zn-chlorin chemical dimers by di- or tetrapyridyl substituted porphyrins, chlorins or tetrahydroporphyrins. Spectral, photophysical and ther-modynamic properties of the ensembles have been studied in the temperature range from 140 to 360 K. Kinetic behavior of the complexes upon optical excitation was investigated using a fluorescent picosecond laser setup (triangle opent approx =30 ps) with 2-D (wavelength-lifetime) registration. Observed spectral properties are explained in terms of extra-ligation and excitonic coupling. Nonradiative forward and backward excitation energy transfer (ET), electron transfer and d-pi interactions are discussed as the main paths of electronic excitation deactivation in the complexes.