Two-dimensional oxides constructed from octamolybdate clusters and Mn+/tetrapyridylpyrazine subunits (M = Co, Ni: n=2; M = Cu: n=1)

The hydrothermal reactions of MoO3, tetra-2-pyridylpyrazine (tpyprz) and M(CH3CO2)(2) (.) 2H(2)O (M = Co, Ni) yielded the two-dimensional oxides [M-2(tpyprz)(H2O)(2)Mo8O26](.)xH(2)O [M = CO, X = 1-8 (1); M = Ni, x 0.6 (2)]. However, the reaction of (NH4)(6)MOo(7)O(24) (.) 4H(2)O, tpyprz and Cu(CH3CO2)(2). H2O produced [{Cu-2(tpyprz)}(2)Mo8O26] (.) 2H(2)O (3 (.) 2H(2)O). The isomorphous structures of 1 and 2 are constructed from alpha-Mo8O264- clusters linked through {M-2(tpyprz)(H2O)(2)}(4+) subunits into two-dimensional networks. While the structure of 3 is also two-dimensional, the molybdate building block is present as the delta-isomer and the secondary-metal/ligand component consists of a one-dimensional {Cu-2(tpyprz)}(n)(2n+) chain. The structure of 3 is compared to that of the previously reported three-dimensional material [{Cu-2(tpyprz)}(2)Mo8O26] (.) 7H(2)O which contains zeta-Mo8O264- clusters and structurally distinct {Cu-2(tpyprz)}(n)(2n+) chains. (C) 2004 Elsevier B.V. All rights reserved.