A tris-oxovanadium pyrogallate complex: synthesis, structure, and magnetic and electronic properties

Abstract

With the aim of identifying new cation–phenolate complexes, we herein investigated the reactivity of pyrogallol (H₃pgal) with vanadium salts. A trimetallic anionic complex was identified, and found to be formed under a broad set of reaction conditions. This complex, with the formula V₃O₃(pgal)₃³⁻, consists of three oxovanadium(IV) units connected together by three pyrogallate ligands to afford a bowl-shaped species presenting a pseudo 3-fold symmetry axis. Its crystal structure is reported, as well as its characterisation by a broad set of techniques, including powder X-ray diffraction, thermogravimetric analysis, infrared and Raman spectroscopy, and solid state UV-visible diffuse reflectance. Its redox activity both in solution and in the solid state is described, together with its magnetic behavior. Finally, the relevance of this trimetallic unit in the field of phenolic-based biocoatings and Metal Organic Framework (MOF) synthesis is briefly discussed.