Phosphatovanadium chemistry: new compounds, including an example of 'Tenne's prospect', and oxidation of cyclohexadiene

Several phosphatovanadium cluster compounds with embedded halide ions were investigated. They include the chloride (VO)6(O3POSiMe3)8Cl and the fluoride Et4P (sup +) (V2O3)2(O3PPh)4F (sup -) and the methylphosphato and butyl phosphato analogues of the fluoride compound. Both enable the oxidation of 1,4-cyclohexadiene to benzene in hot pyridine mixture. In addition, both have only three oxygen atoms per phosphorus for cluster bonding, thus allowing the phosphorus centers to serve as sites of positive Gaussian curvature.