catena-Poly[[μ-5,5′-iminoditetrazolato-κ3N,N′:N"-bis[triaquazinc(II)]] bis[[triaquazinc(II)]-μ-5,5′-iminoditetrazolato-κ3N,N′:N"] dihydrate]

The title compound, {[Zn-2(C2HN9)(2)(H2O)(6)][Zn-2(C2HN9)(2)( H2O)(6)]center dot 2H(2)O}(n), consists of one dinuclear [Zn(C2HN9)( H2O)(3)](2) molecule, in which the two C2HN9- monoanions each N,N'-chelate a [Zn(H2O)(3)] unit while using a third N atom to bind to the other triaquazinc unit. In the second [Zn(C2HN9)(H2O)(3)] unit, the monoanion similarly N, N'-chelates a triaquazinc unit, but the bridging interaction furnishes a zigzag chain structure. For both Zn centres, a mer-ZnN3O3 octahedral coordination arises. A network of N-H center dot center dot center dot N, O-H center dot center dot center dot N and O-H center dot center dot center dot O hydrogen bonds helps to establish the structure.