Synthesis and X-ray single crystal study of niobium and tantalum oxo-ethoxo-perrhenates, M4VO2(OEt)14(ReO4)2

Niobium and tantalum oxo-ethoxo-perrhenates, M4VO2(OEt)14(ReO4)2, are easily obtained in high yields via interaction of metal ethoxides, MV(OEt)5, with rhenium heptoxide, Re2O7, in hydrocarbon solvents. The complexes have good solubility in hexane and toluene and are stable in solution at room temperature. Their molecular structures are based on a tetranuclear M4(μ-O)2(μ-OR)4X12 core, X = OR, ReO4, composed of two pairs of edge-sharing octahedra joined via two almost linear oxo-bridges containing a rectangular flat M4-arrangement. The perrhenate ligands are attached in a centrosymmetric manner to the two opposite corners of the rectangle.

Reproducibly soluble and solution stable oxo-alkoxo-perrhenate derivatives of niobium and tantalum, M4VO2(OEt)14(ReO4)2, can be obtained in high yields by interaction of MV(OEt)5 with rhenium heptoxide.Figure optionsDownload as PowerPoint slide