Three new compounds based on similar molybdenum–vanadium clusters and several types of copper complexes

Abstract

Three new compounds based on polyoxometalates and transition metal complexes have been prepared and characterized by IR and UV-vis spectroscopy, powder XRD, photoluminescence analysis, elemental analysis and X-ray diffraction analysis. Single crystal X-ray analysis reveals that both {[PMo₁₀V₄O₄₂][Cu(phen)]₂}[Cu(im)₂][Cu(phen)(im)]₂ (1) (im = imidazole, phen = 1,10-phenanthroline) and {[PMo₉V₅O₄₂][Cu₂(2,2′-bpy)₂(C₂O₄)]}[Cu(2,2′-bpy)₂(H₂O)][Cu(2,2′-bpy)₂(Cl)]·3H₂O (2) (bpy = bipyridine) contain three types of copper complexes, any one of which is different from the others. {[PMo₈V₆O₄₂][Cu(DABCO)]₂[Cu(phen)₂]}·3H₂O (3) (DABCO = triethylenediamine) exhibits a novel 2-D layered framework structure constructed from [PMo₈V₆O₄₂]⁴⁻ and two different types of copper complexes, and also compound 3 is the first extended POM compound based on {M(phen)₂} bridges. In addition, the catalytic properties of compounds 1–3 have been investigated and all of them are excellent catalysts for the epoxidation of styrene.