An octabrominated Sn(IV) tetraisopropylporphyrin as a photosensitizer dye for singlet oxygen biomedical applications

Two novel Sn(IV) tetraisopropylphenylporphyrins have been synthesized to explore the effect of octabromination at the beta-pyrrole positions on their photophysical properties and photodynamic activity. The lower energy Q band of an octabrominated complex lies at 675 nm well within the therapeutic window. The octabrominated dye has a relatively high singlet oxygen quantum yield of 0.78 in DMF and exhibits favorable photodynamic activity against MCF-7 cells with an IC50 value of 10.7 mu M and a 5.74 log reduction value (5 mu M) towards S. aureusunder illumination at 660 nm for 60 min with a Thorlabs M660L3 LED (280 mW cm(-2)).