Silicon photosensitizers in cancer therapy: Theoretical studies on novel 5‐methoxypsoralens

Three novel silicon photosensitizers (PSs) are discovered with prospects to be utilized in psoralen ultra‐violet A (PUVA) cancer therapy, at B3LYP/6‐311++G** level of theory. They include 5‐methoxysilolo[3,2‐g]chromen‐2(8H)‐one (1), 5‐methoxybenzo[4,5]silolo[3,2‐g]chromen‐2(10H)‐one (2), and 11‐methoxybenzo[c]silolo[3,2‐g]chromen‐5(8H)‐one (3). Structures 1‐3 exhibit intense narrow absorption peaks in the ultra violet A (UVA) therapeutic window and show T1 energies necessary to activate the ground state triplet molecular oxygen (3O2) to its singlet excited state (1O2). Unprecedented 5‐methoxypsoralen derivatives (1‐3) appear as efficient photosensitizers (PSs) for converting triplet ground molecular oxygen (3O2) to its singlet excited state (1O2), in psoralen ultra‐violet A (PUVA) cancer therapy, at 6‐311++G** level of theory.