Aerobic photocatalytic oxidation of adamantane with heteropolyoxometalates [X(n+)W(12)O(40)](8-n) where X=Si,Co2+,Co3+

Photolysis (lambda>260 nm) of dioxygen saturated acetonitrile-water (98/2) solution of 1:12 heteropolytungstates [X(n+)W(12)O(40)](8-n) where X = Si (1), Co2+ (2), Co3+ (3) and adamantane give a mixture of adamantanol-1, adamantanol-2 and adamantanone in 4:1:3 ratio. The quantum yields of this photooxidation reaction catalyzed by 1-3 are 5.5 . 10(-3) 4.5 . 10(-3) and 0.8 . 10(-3), respectively. The suggested mechanism envisages the hydroperoxides formation in the solvent cage followed by their photodecomposition to alcohols and ketone.