Deep-Red Photocatalysis via Charge-Transfer Excitation of a Dicationic Ru(II) Sensitizer Using 740 nm Light

We report rare examples of deep-red Ru(II) photochemistry from a charge-transfer (CT) excited state using [Ru(bpy)2(p-biphe)](PF6)2 (bpy = 2,2′-bipyridine; p-biphe = 6,6′,7,7′-biphenanthridine). The absorption of deep-red light (740 nm) generates a dark but reactive CT excited state that can be harnessed in proof-of-principle reductive and oxidative electron-transfer and energy-transfer photocatalysis.