Novel modified BODIPY–C60 as photosensitizer in photodynamic therapy

Abstract

We have designed a novel BF2-chelated azadipyrromethene-fullerene dyad as a highly efficient photosensitizer (PS) for photodynamic therapy (PDT) at the B3LYP/6-31G(d) ∼ LANL2DZ theoretical level. The 4,4-difluoro-2,6-diiodo-1,3,5,7-tetramethyl-8-phenyl-4-bora-3a,4a-diaza-s-indacene (2I-BODIPY) with an azido substituent and fullerene (C60) were used to prepare this novel PS (2I-BODIPY-C60). Furthermore, the scrutinized results suggest that PS exhibits intense absorption in the therapeutic window (600–800 nm). The energy of the first triplet excited state (T1) of the photosensitizer lies above the excitation energy of the ground- state molecular oxygen (0.98 eV). On the other hand, the energy gap between the ground state (S0) and the T1 state of the present PS is 1.58 eV. In consideration of these results, 2I-BODIPY-C60 displays an efficiently radiationless intersystem crossing (ISC) and has a sufficient energy for generating singlet molecular oxygen (1O2). Accordingly, 2I-BODIPY-C60 would be proposed as a potential PS for PDT.