The photophysics and photochemistry of the salt [(bpy)Re(CO)(3)(py)(+)][BzBPh(3)(-)] (ReBo, where bpy = 2,2’-bipyridine, py = pyridine, Bz = C6H5CH2 and Ph = C6H5) has been investigated in THF and CH3CN solutions. W-visible absorption and steady-state emission spectroscopy indicates that in THF ReBo exists primarily as an ion-pair. A weak absorption band is observed for the salt in THF solution that is assigned to an optical ion-pair charge transfer transition. Stern-Volmer emission quenching studies indicate that B(2)BPh(3)(-) quenches the luminescent d pi (Re) --> pi* (bpy) metal-to-ligand charge transfer excited state of the (bpy)Re(CO)(3)(py)(+) chromophore. The quenching is attributed to electron transfer from the benzylborate anion to the photoexcited Re(I) complex, (bpy(-.))Re-II(CO)(3)(py)(+*) + BzBPh(3)(-) --> (bpy(-.))Re-I(CO)(3)(py) + BzBPh(3)(.). Laser flash photolysis studies reveal that electron transfer quenching leads to irreversible reduction of the Re(I) cation to (bpy(-.))Re-I(CO)(3)(py). Photoinduced electron transfer is irreversible owing to rapid C-B bond fragmentation in the benzylboranyl radical, PhCH(2)BPh(3)(.) --> PhCH(2)(.) + BPh(3)(.). Quantitative laser flash photolysis experiments show that the quantum efficiency for production of the reduced complex (bpy(-.))Re-I(CO)(3)(py) is unity, suggesting that C-B bond fragmentation in the benzylboranyl radical occurs more rapidly than return electron transfer within the geminate radical pair that is formed by photoinduced electron transfer.