Synthesis, Characterization, Electronic Structure, and Excitation Dynamics of Dinuclear Copper(I) Complexes with a Naphthyridine Diimine Ligand

Novel photosensitizer paradigms featuring Earth-abundant metals are highly sought after due to their low cost, low toxicity, and abundance. In this study, we pursue a bimetallic paradigm for an Earth-abundant-metal photosensitizer design. We describe the synthesis, structure, and photophysical properties of a series of dicopper(I) complexes supported by a naphthyridine diimine ligand. Time-resolved spectroscopic and computational studies reveal excited states with (MM)LCT character formed at absorptions in the visible range. The excited-state lifetimes of these complexes are slightly perturbed by the anionic counterions bound to copper.