A Reduced Polyoxomolybdenum Borophosphate Anion Related to the Wells−Dawson Clusters

The new compound (C3N2H5)8[MoV5MoVI7O22(BO4)2(PO4)5(HPO4)3]·nH2O is the first molybdenum borophosphate. It contains clusters of twelve molybdenum, eight phosphorus and two boron atoms, [Mo12O22(BO4)2(PO4)5(HPO4)3]8- similar to the Wells−Dawson clusters. Five molybdenum atoms are MoV while the others are MoVI, and the five electrons are delocalized. According to the temperature dependence of the magnetic susceptibility four of these electrons are paired.