Catalysis by well characterized materials - discussion

General discussion: Prof. R. A. van Santen (University of Technology, Eindhoven, The Netherlands commented: I would like to point out that the predicted reactivity of bridging 0 species agrees with the results of Pauling's valency rules. I would like, to ask whether it would not be better to study clusters containing Mo as well as V, since the acidic proton coordinated to the bridging oxygen is generated by vanadium. If one were to apply thermodynamic arguments, which of the oxygens (bridging or monocoordinated) would be most active