1H-Benzotriazol-3-ium (1H-benzotriazole-κN 3)trichloridocobaltate(II) monohydrate: a reformulation

The asymmetric unit of the title compound, (C6H6N3)[CoCl3(C6H5N3)]·H2O, contains two crystallographically independent cations, two anions and two water molecules. The structure has been reported previously [Zhang, Li, Wang, Xie, Wang & Shen (2004 ▶). Acta Cryst E60, m498–m500] as a neutral cobalt(III) complex accompanied by unprotonated benzotriazole molecules and here has been redetermined as an anionic cobalt(II) complex accompanied by protonated benzotriazole cations. For both complex anions, a tetrahedral CoNCl3 geometry arises. A network of N—H⋯O, N—H⋯Cl, O—H⋯O and O—H⋯Cl hydrogen bonds helps to establish the packing.


Experimental
Crystal data (C 6
A decrease of the metal oxidation number in (I) from III to II requires the presence of an additional proton for charge balance. In fact, an analysis of difference Fourier maps has shown two peaks in the positions expected for missing benzotriazole H atoms (N-Q = 0.85 and 0.89 Å). Both of these are involved in short, strong N-H···O water hydrogen bonds which confirms the supposition (Fig. 1). The N-N bond lengths in the benzimidazolium cations are practically equalized and range from 1.309 (4) to 1.316 (5) Å, indicating full delocalization of their π electrons, which is not observed in neutral benzotriazole molecules (Krawczyk & Gdaniec, 2005). The metal bond distances and hydrogen bonds are listed in Tables 1 and 2, respectively.

S2. Experimental
Due to the unsuccesful attempts at the synthesis of (I), the deposited structure factors and other data have been taken from the original paper of Zhang et al. (2004).

S3. Refinement
All H atoms were located in difference Fourier syntheses but were repositioned with ideal geometry (  A view of (I), showing displacement ellipsoids for the non-H atoms drawn at the 30% probability level.

1H-Benzotriazol-3-ium (1H-benzotriazole-κN 3 )trichloridocobalt(II) monohydrate
Crystal data (13) Special details Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All su's are estimated from the variances of the (full) variance-covariance matrix. The cell e.s.d.'s are taken into account in the estimation of distances, angles and torsion angles Refinement. Refinement on F 2 for ALL reflections except those flagged by the user for potential systematic errors. Weighted R-factors wR and all goodnesses 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 observed criterion of F 2 > σ(F 2 ) is used only for calculating -R-factor-obs 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.