The electronic structures and excitation properties of three mesopentafluorophenyl substituted zinc porphyrin-fullerene dyad

Understanding electronic structures and excitation properties is a fundamental issue to develop novel electron donor (D) and acceptor (A) molecular dyad that can be applied in optoelectronic systems. Here, the geometry, electronic structures, and excitation properties of three meso-pentafluorophenyl substituted zinc porphyrin fullerene ((F15P)ZnP C-60) dyad were analyzed based on density functional theory (DFT) and time dependent DFT (TDDFT) calculations. The geometrical parameters provide the D-A distance is about 18.19 angstrom. The electronic structure analysis indicates that the highest occupied molecular orbital and the lowest unoccupied molecular orbital are localized in porphyrin core and C-60, respectively. The transition configurations and the MOs suggest the excited states at the absorption maxima are local excited states, while the charge transfer (CT) states are transient intermediates. The population analysis supports the first singlet/triplet excited states are local excitations in porphyrin (LEP). Quasi-degeneracy of excited states between LEP and local excitation in C-60 (LEC) enable the partial delocalization of eigenstates and excitation-energies over the D and A in dyad, while the quasi-degeneracy between CT and LEP generate synergistic enhancement effects for CT. The results of this work could be helpful to understand optoelectronic properties of (F15P)ZnP C-60 dyad. (C) 2018 Elsevier B.V. All rights reserved.