Organophosphonate-Functionalized Telluromolybdate Containing a [TeMoO] Building Block and Its Catalytic Efficiency for Knoevenagel Condensation.

A novel organodiphosphonate-based telluromolybdate cluster, (NH)NaH[TeMoO(CoMoOL)]·11HO [; L = (OP)C(O)(CH)NH], has been successfully synthesized by a simple one-pot aqueous reaction. Intriguingly, the [TeMoO] subunit with tetrahedral geometry of TeO is observed in the organophosphonate-functionalized polyoxometalates for the first time. Compound was prepared in a buffer solution (pH = 5.5) with alendronic acid (Ale) and (NH)MoO·4HO as raw materials. The polyanion [TeMoO(CoMoOL)] was constructed from four {MoOL} subunits encapsulating an interesting Te-Mo heterometal subunit [TeMoO] through four CoO octahedra and has been fully characterized by routine techniques. In addition, compound , as a heterogeneous catalyst, shows good conversion (92%) and high selectivity (99%) for Knoevenagel condensation reaction.