Electron Transfer in a Li+-Doped Zn-Porphyrin-[10]CPP⊃Fullerene Junction and Charge-Separated Bands with Opposite Response to Polar Environments.

ABSTRACT

Recently synthesized porphyrin-cycloparaphenylene (ZnP-[10]CPP) junction is a powerful platform to develop useful organic photovoltaic devices. In this work, we computationally study photoinduced electron transfer processes in the supramolecular complex ZnP-[10]CPP⊃C60 and its Li+-doped derivative. The most striking finding is charge-separated (CS) bands in ZnP-[10]CPP⊃Li+@C60 with opposite response to solvent polarity. Besides CS bands that demonstrate a bathochromic shift, there exist CS transitions showing a rarely observed hypsochromic shift. The rates of energy transfer, charge separation, and charge recombination in the supramolecular complexes are computed by using the semiclassical approach. These estimates suggest that the both types of CS states can be efficiently populated in polar media by decay of locally excited states.