PHOTOCATALYTIC AND AEROBIC OXIDATION OF SATURATED ALKANES BY A NEUTRAL LUMINESCENT TRANS-DIOXOOSMIUM(VI) COMPLEX [OSO2(CN)(2)(DPPHEN)]

A neutral trans-dioxoosmium(VI) complex [OsO2(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 o xidizing [E degrees(OsVI-V) = 2.15 V vs, NHE; lifetime 0.95 mu s; quan tum yield = 5 x 10(-4); lambda(em)(max.) = 650 nm]; under UV-VIS irrad iation and in the presence of dioxygen, cyclohexane is oxidized to cyc lohexanol 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 .