[fac-Re(bpy)(CO)(3){4(MeCO)py}](+) can act as an efficient photocatalyst for the reduction of 4-acetylpyridine to a pinacol (py-CMeOHCMeOH-py) in the presence of triethanolamine. The reaction proceeds via formation of a pinacol complex [fac-Re(bpy)(Co)(3)(py-CMeOHCMeOH-py)](+).