(1,4,7,10-Tetra-aza-cyclo-dodecane-κN,N,N,N)(tetra-oxidomolybdato-κO)copper(II) monohydrate.

In the title compound, [CuMoO(4)(C(8)H(20)N(4))]·H(2)O, the Cu(II) atom is coordinated by four N atoms of the 1,4,7,10-tetra-aza-cyclo-dodecane (cyclen) ligand and one O atom of the molybdate unit in a distorted square-pyramidal environment. The water mol-ecules are linked to the complex unit to form centrosymmetric dimers [R(4) (4)(12) and R(4) (4)(16)] and discrete D(3) (2)(9), D(3) (3)(11) and D(3) (3)(13) chains by O-H⋯O and N-H⋯O inter-actions. Additionally, the complex mol-ecules are linked into C(4) (4)(18) chain motifs by N-H⋯O inter-actions. As a result [(cyclen)CuMoO(4)] units and water molecules are linked to layers that are oriented parallel to the ac plane. The stacking of the layers in the b-axis direction is supported by weak C-H⋯O hydrogen bridges.