Long-Lived Photoexcited State of a Mn(IV)-Oxo Complex Binding Scandium Ions That is Capable of Hydroxylating Benzene

Photoexcitation of a Mn-IV-oxo complex binding scandium ions ([(Bn-TPEN)Mn-IV(O)](2+)-(Sc-(OTf3)(2)) in a solvent mixture of trifluoroethanol and acetonitrile (v/v = 1:1) resulted in formation of the longlived photoexcited state, which can hydroxylate benzene to phenol. The photohydroxylation of benzene by [(Bn-TPEN)Mn-IV(O)](2+)-(Sc(OTf3)(2) was made possible by electron transfer from benzene to the long-lived E-2 excited state of [(Bn-TPEN)Mn-IV(O)](2+)-(Sc(OTf3)(2) to produce a benzene radical cation, which reacted with water as revealed by laser-induced transient absorption measurements.