STEREOCHEMICAL CONTROL OF CLUSTER-SIZE IN VANADIUM PHOSPHATES

Structures of some newly synthesized vanadium phosphate clusters demonstrates that the nuclearity can be influenced by a variation in the number of open coordination sites on the vanadium center and the denticity of the bridging phosphates. The smallest cluster, [HB(pz)3]2(VO)2[(mu-C6H5O)2PO2]2, is obtained with the most coordinatively restricted vanadium precursor complex and a bidentate phosphate diester; conversely, the largest cluster arises from the reaction of the least restricted vanadium precursor with a tridentate phosphate monoester. These results suggest that rational design of vanadium phosphate clusters can be achieved through judicious control of ancillary metal ligation, phosphate denticity, and reaction condition.