From the First Sulfurated Keggin Anion to a New Class of Compounds Based on the [M2O2S2]2+ Building Block M=Mo,W

Abstract

Different strategies of synthesis were developed to introduce sulfur atoms in a polyoxometalate framework. Every synthetic route provides new and specific sulfur-containing compounds, characterized by single crystal X-ray diffraction and multinuclear NMR spectroscopy in solution. The first investigations based on conventional routes of synthesis give predictable oxo-thio Keggin-like clusters while an original strategy, based on the acid-base self-condensation of an oxo-thio building block is the origin of a new generation of polymetalates. Finally, under hydrothermal conditions, successive replacements of sulfur atoms by oxygen atoms take place and unexpected molecular associations between fully oxygenated saturated Keggin anions were obtained.KeywordPolyoxothiometalatescyclic clustermolybdenum31P NMR183W NMR