Here, we have synthesized and characterized three visible light responsive terpyridine based-Re(I)-tricarbonyl complexes; [Re(CO)3(ph-tpy)Cl] (Retp1), [Re(CO)3(an-tpy)Cl] (Retp2), and [Re(CO)3(py-tpy)Cl] (Retp3) where ph-tpy = 4'-phenyl-2,2':6',2''-terpyridine; an-tpy = 4'-anthracenyl-2,2':6',2''-terpyridine, py-tpy = 4'-pyrenyl-2,2':6',2''-terpyridine....