Targeted synthesis of a polypyridyl polyoxometalate coordination complex using microwave-assisted reaction conditions

In this article, we build upon our recent efforts that have focused on demonstrating the value of microwave-assisted synthesis in polyoxometalate (POM) chemistry. Herein, we report for the first time a microwave-assisted approach that enabled the facile preparation and crystallization of a large POM-containing coordination complex. The judicious selection and reaction of a sparingly water-soluble transition-metal-substituted polyanion (TMSP) salt with the tritopic ligand 2,4,6-tris(4-pyridyl)-1,3,5-triazine (TPT) in a mixed solvent system under moderately forcing conditions yields Ba₉[(B^IIIW^VI₁₁O₃₉Co^III)₃(C₁₈H₁₂N₆)]·38H₂O in moderate yield. Crystallographic analysis reveals significant intermolecular interactions between the organic ligand and neighbouring polyanions, predominantly C-H...O(water) in nature; meanwhile, the solvated regions of the crystal show significant disorder. To supplement the crystallographic study, combustion analysis, and IR and ¹H NMR spectroscopic analyses were conducted, revealing good bulk purity and the stability of the complex in aqueous media.