Ligand mediated valence fluctuation of copper in new hybrid materials constructed from decavanadate and a Cu(1,10-phenanthroline) complex

Abstract

Two new organic hybrid materials [H4V10O28][CuCl(Hn(2)O)2(1,10-phenanthroline)](2)center dot 4H(2)O (V10O28-CuCl-phen) and [H4V10O28][Cu(H2O)3(1,10-phenanthroline)](2)center dot 4H(2)O (V10O28-CuO-phen) were synthesized at room temperature. The effect of the presence and absence of AlCl3 on the single crystal growth of the two compounds was studied. The compounds were characterized using single crystal X-ray diffraction (XRD), scanning electron microscopy, energy dispersive spectroscopy, infra-red spectroscopy and thermogravimetric analysis. XRD studies on selected single crystals suggest that the compounds consist of supramolecular 3D layer structures constructed from a tetra-protonated [V10O28] unit and the organometallic complex Cu(1,10-phen) with Cl and 2H(2)O molecules in the presence of AlCl3 in V10O28-CuCl-phen and with 3H(2)O molecules in V10O28-CuO-phen which was confirmed by TGA studies. Both compounds crystallize in the triclinic space group P (1) over bar : a = 8.3886(3) angstrom, b = 10.4266(4) angstrom, c = 13.5860(5) angstrom, a = 92.440(2)degrees, angstrom = 92.315(2)degrees, gamma=98.160(2)degrees for V10O28-CuCl-phen and a = 8.3733(5) angstrom, b = 10.4132(6) angstrom, c = 13.5904(8) angstrom, a = 92.295(4)degrees, beta = 92.331(2)degrees, gamma = 98.086(4)degrees for V10O28-CuO-phen. Magnetic measurements suggest that Cu exists in magnetic +2 oxidation state in V10O28-CuCl-phen and non-magnetic +1 oxidation state in V10O28-CuO-phen.