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

Abstract

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[(BIIIWVI 11O39CoIII)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.