Photocatalytic and aerobic oxidation of saturated alkanes by a neutral luminescent trans-dioxoosmium(vi) complex [OsO2(CN)2(dpphen)]

Abstract

A neutral trans-dioxoosmium(VI) complex [OsO ₂ (CN) ₂ (dpphen)] (dpphen = 4,7-diphenyl-1,10-phenanthroline) is prepared and characterized by X-ray crystal analysis; the excited state is long-lived, emissive and oxidizing[E°(Os ^VI–V ) = 2.15 V vs. NHE; lifetime = 0.95 µs; quantum yield = 5 × 10 ^{- 4} ; λ _em (max.) = 650 nm]; under UV–VIS irradiation and in the presence of dioxygen, cyclohexane is oxidized to cyclohexanol and cyclohexanone with a turnover number of 16; secondary C–H bonds of propane and primary C–H bonds of n-hexane are also oxidized.