Construction of bimetallic oxide materials from molybdate building blocks and copper–ligand tethers with flexible spaces: Structures of the two-dimensional [{Cu2(L4)(H2O)2}Mo8O26(H2O)2] and of the three-dimensional [{Cu2(L4)}2(Mo8O26)(MoO4)2] (L4 = N1, N1

The hydrothermal reactions of cupric acetate, MoO3 and the dipodal linker ligand N1, N1, N4, N4-tetrakis(pyridin-2-ylmethyl)butane-1,4-diamine (L4) provided a high temperature phase [{Cu2(L4)(H2O)2}Mo8O26(H2O)2]·2H2O (·2H2O) and a low temperature phase [{Cu2(L4)}2{Mo8O26}{MoO4}2]·2H2O (·2H2O). Compound 1 is two-dimensional, constructed from {Mo8O26(H2O)2}4− clusters linked through {Cu2(L4)(H2O)2}4+ rods. In contrast, compound 2 is three-dimensional with two distinct molybdate building blocks, γ-{Mo8O26}4− clusters and {MoO4}2− tetrahedra, linked through two distinct {Cu2(L4)}4+ subunits, one connecting four {MoO4}2+ tetrahedra and the second a {MoO4}2+ tetrahedron and one octamolybdate cluster.