Photoinduced electron transfer in multi-chromophore system: unusual environmental effects in fullerene-Zn-porphyrin-BODIPY triad

Abstract

Molecular arrays containing donor-acceptor sites and antenna molecules are promising candidates for organic photovoltaic devices. Photoinduced electron transfer (PET) in multi-chromophore systems is controlled by a subtle interplay of donor and acceptor properties and solvent effect. In the present study, we explore how PET of fullerene [C60]-Zn-Porphyrin-BODIPY triad can be modulated by passing from non-polar to polar media. To this aim we perform computational study of this complex using the DFT/TDDFT method. [C60]-Zn-Porphyrin-BODIPY demonstrates significant contrast between stabilization of CT states in which the BODIPY moiety acts as electron donor forming or electron acceptor. To understand the effect of the environment polarity on the PET processes a detailed analysis of initial and final states involved in the ET is performed. Computed electron transfer rates revealed the dependence of photoinduced charge separation properties on the environment, namely we found that increase in solvent polarity leads to the involvement of an additional deactivation channel, which does not play a role in non-polar solvents