Executive Summary : | Heteroleptic ruthenium(II) and cyclometalated iridium(III) polypyridyl complexes are promising for chemosensors, photo and electrocatalysts due to their visible light absorption, long-lived excited states, and excellent redox properties. Ru(II) and Ir(III) complexes are chosen for their low cytotoxicity, good aqueous solubility, and cell permeability. The diverse photophysical/chemical properties of Ru(II) and Ir(III) polypyridine complexes are derived from their triplet metal-to-ligand charge transfer (³MLCT), intraligand (³IL), and ³LLCT states. This diversity enriches the photo properties of these complexes and allows for fine-tuning using various polypyridyl/cyclometalated and analyte-targeting ligand systems. The proposal aims to synthesize substituted 1,10-phenanthroline/2,2-bipyridine and 1,2,3-triazole pyridine-based ligands and bis-heteroleptic Ru(II) and Ir(III) complexes, focusing on their redox and excited-state properties. The electron-rich/deficient substituent at the phen/bpy/triazole pyridine ligand will add flexibility to the ligand, resulting in no/very weak emission in the analyte-free condition. The proposed approach aims to utilize the brilliant redox properties of Ru(II) and Ir(III) complexes for electrocatalytic water splitting. Metals such as Ru and Ir are known for their adequate electrocatalytic performance in hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). The proposed approach aims to develop several substituted phen/bpy/triazole pyridine ligands and their Ru(II) and Ir(III) complexes for electrocatalytic OER. |