Synthesis, Characterization, Biomolecular Interaction, and Photobiological Application of Cyclometalated Ir (III) Benzimidazole Complex

ABSTRACT Herein, we report a halogen substituted benzimidazole‐based cyclometalated Iridium complex ( LIr ) for the effective application as a photosensitizer. Detailed studies nailed it as a better type II photosensitizer compared to that of type I. The Complex can generate singlet oxygen ( ɸ = 0.16) via Type II PDT, which aids its proficiency toward the oxidation of Nicotinamide Adenine dinucleotide (NADH) (TOF = 40.13 h −1 ) but didn't respond to extensive studies for generation of ROS, as well as depletion of intracellular Glutathione (GSH) levels. The photostable Ir(III) complex also exhibits significant binding affinity toward various biomolecules, such as DNA ( K b = 0.203 × 10 6 M −1 ) and HSA ( K HSA = 1.39× 10 6 M −1 ), proving it a strong candidate as future PDT agent for the application in preferably through type II pathways and thereby diminishing the cancer cells in effective manner.