Self-assembly of four one-dimensional molybdenum(V) phosphates linked by strontium and transition metal

Four reduced molybdenum(V) phosphates, [(py)(2)(Himi())4][(Fe2SrMo12O24)-Sr-II(OH)(6)(H2O)(8)(H2PO4)(2)(HPO4)(4)(PO4)(2)]center dot 4H(2)O 1, (H(2)bpp)(2)[(Co2Sr2Mo12O24)-Sr-II(OH)(6)(H2O)(8)(H2PO4)(2)(HPO4)(2)(PO4)(4)]center dot 6H(2)O 2, [(Hpy)(Himi)][Ni(H2O)(6)][Ni2Sr2Mo12O24(OH)(6)(H2O)(8)(H2PO4)(2)(HPO4)(2)(PO4)(4)]center dot 4H(2)O 3, (H(2)imi)(2)[Zn2Sr2Mo12O24(OH)(6)(H2O)(6) (H2PO4)(2)(HPO4)(2)(PO4)(4)]center dot 3H(2)O(4) (imi = imidazole, bpp = 1,3-bi(4-pyridyl)-propane, py = pyridine), have been obtained by hydrothermal methods. These structures were determined by single-crystal X-ray diffraction analysis and were further characterized by elemental analysis, IR, and TG analysis. All the compounds contain the [P4Mo6O31](12) (abbreviated as [P4Mo6]) polyoxoanions as building blocks, which are further connected into the sandwich-type dimeric units by various transition metal (TM) ions. In compound 1, the dimeric {Fe[P4Mo6] 2} units are bonded by an heterometallic {SrFe} binuclear unit to form 1-D string. In compounds 2-4, the dimeric {(TM)[P4Mo6](2)} units are linked by new {Sr2TM} trinuclear fragments into one-dimensional (1-D) chains. All the 1-D chains are further packed into various three-dimensional (3-D) supramolecular assemblies via strong hydrogen-bonding interactions. Furthermore, the electrochemical activities of compounds 1-4 and magnetic properties of compounds 1-3 are reported. (C) 2011 Elsevier B. V. All rights reserved.