Bis{3-amino-1-carbamothioyl-5-[(2-{[(5-methyl-1H-imidazol-3-ium-4-yl)methyl]sulfanyl}ethyl)amino]-1H-1,2,4-triazol-4-ium} hexachloridobismuthate(III) nitrate dihydrate

The asymmetric unit of the title hydrated salt, (C10H18N8S2)2[BiCl6]NO3·2H2O, contains two independent 3-amino-1-carbamothioyl-5-[(2-{[(5-methyl-1H-imidazol-3-ium-4-yl)methyl]sulfanyl}ethyl)amino]-1H-1,2,4-triazol-4-ium cations, one hexachloridobismuthate anion, one nitrate anion and two solvent water molecules. The dihedral angles between the imidazole and triazole rings in the cations are 44.7 (3) and 89.4 (3)°. The BiIII ion is coordinated by six chloride ligands in a slightly distorted octahedral geometry. In each cation, an intramolecular N—H⋯S hydrogen bond is observed. In the crystal, N—H⋯Cl, N—H⋯S, N—H⋯O, O—H⋯Cl, O—H⋯S and O—H⋯O hydrogen bonds connect the components into a three-dimensional network. In addtion, π–π stacking interactions between inversion-related triazole rings are observed, with a centroid–centroid distance of 3.322 (3) Å

The molecular structure of the title compound is shown in Fig. 1. The asymmetric unit compound, contains of two dicationic ligands, one [BiCl 6 ] 3anion, one NO 3anion and two solvent water molecules. The Bi III ion is coordinated by six chloride ions forming a slightly distorted octahedral configuration with Bi-Cl bond lengths ranging from 2.6312 (13)

Experimental
Bismuth nitrate (0.4851 g, 1.0 mmol) was dissolved in 4M hydrochloric acid (30 ml). An ethanolic solution of cimetidine (0.5047 g, 2.0 mmol) and thiosemicarbazide (0.1823 g, 2.0 mmol) were added slowly to the solution with constant stirring. The solution was stirred further for 3 h and then it was filtered and left with slow evaporation of the solvent.
Colorless crystals suitable for X-ray analysis separated out from the solution after a week.

Refinement
H atoms bonded to C atoms were placed in calculated positions [C-H = 0.95 Å, 0.98 Å and 0.99 Å] and refined in a riding-model approximation with U iso (H) = 1.2U eq (C) or U iso (H) = 1.2U eq (C methyl ). H atoms bonded to N and O atoms were refined independently with a common isotropic displacement parameter for each type.   Packing diagram of the complex. Hydrogen bonds are shown by dashed lines.

Special details
Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes. Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > σ(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.