N—H...S and N—H...O hydrogen bonding in tetra-n-butyl­ammonium (imidazolidine-2-thione-2κS)dioxo-1κ²O-di-μ-sulfido-1:2κ⁴S:S-copper(I)tungstate(VI)

In the title complex, (C₁₆H₃₆N)[WCuO₂S₂(C₃H₆N₂S)], the W and Cu atoms have tetra­hedral and trigonal-planar coordination, respectively. Two sulfide ligands bridge the two metal centres; tungsten is additionally coordinated by two terminal oxo ligands and copper by the exocyclic S atom of imidazolidine-2-thione. There is an intra­molecular N—H...S hydrogen bond in the anion, and anions are linked into chains by N—H...O inter­molecular hydrogen bonds. The more loosely held cation is disordered.

N,N'-Dimethyl­piperazinium(2+) bis­[methyl­enehydrogendiphospho­nate(1-)]

The asymmetric unit of the title compound, C₆H₁₆N₂²⁺·2(HO)₂(O)PCH₂P(O)₂(OH)^-, contains two singly charged diphospho­nate anions and two half-cations, each doubly charged cation lying on an inversion centre. Single deprotonation of methyl­enediphospho­nic acid to give a salt with an organic amine is unprecedented, double deprotonation being normal. All N-H and O-H groups act as hydrogen-bond donors in the crystal structure, with unproton­ated O atoms as the acceptors, giving a three-dimensional network.