The effect of C60 on the optical absorption properties of HPPH photosensitizer

Abstract

The optical absorption properties of the clinical photosensitizer (HPPH) and HPPH-C60 dyads (HPPH-C60 (1), HPPH-C60 (2) and HPPH-C60 (3)) have been calculated by density functional theory (DFT) and time dependent density functional theory (TD-DFT). Based on the optimized geometrical structures of three HPPH-C60 dyads, their binding energies, the charges populations and the excited energies are calculated specifically. The results show that the different binding sites between C60 and HPPH induce the different binding energy. The maximum binding energy and the significant charge transfer occur at C60 and nitrogen atoms of HPPH in HPPH-C60(1). At the same time, the excited energies of three HPPH-C60 dyads are smaller than that of HPPH. The maximum absorption peak of the HPPH-C60(1) reaches near infrared 961.69nm.