Photoinduced Multistep Charge Separation in a Heteroleptic Cu(I) Bis(phenanthroline)-Based Donor–Chromophore–Acceptor Triad

A molecular triad assembly consisting of an electron donor, a bis(phenanthroline)copper(I) chromophore, and an electron acceptor has been prepared. Under visible-light excitation, this assembly undergoes efficient (ca. 50%) photoinduced, multistep formation of a diradical cation charge-separated state that has a lifetime of >100 ns and stores >1.0 eV of energy. This system constitutes an earth-abundant functional analogue of related Ru(bpy)3 triad systems.