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The asymmetric unit of the title compound, [CoCl2(C3H6N4)]n, contains two Co atoms, both lying on inversion centres, two Cl atoms and one 1,5-dimethyltetrazole ligand. The coordination polyhedra of both Co atoms adopt flattened octahedral geometry, with two N atoms from two ligands in axial positions and four Cl atoms in equatorial sites. Neighbouring Co atoms are linked together via two bridging Cl atoms and one tetrazole ring to form polymeric chains running along the a axis.
Data collection: local program; cell refinement: FULLPROF (Rodríguez-Carvajal, 2001 ); data reduction: local program; program(s) used to refine structure: FULLPROF; molecular graphics: PLATON (Spek, 2003 ); software used to prepare material for publication: FULLPROF, SHELXL97 (Sheldrick, 2008 ) and PLATON (Spek, 2003 ).
Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809003018/cv2491sup1.cif
Rietveld powder data: contains datablocks I. DOI: 10.1107/S1600536809003018/cv2491Isup2.rtv
This work was supported by the Belarusian Foundation for Fundamental Research (grant No. X08-139).
A solution, containing 1.17 g (0.005 mol) of CoCl2.6H2O in 10 ml of a mixture of methanol and triethyl orthoformate (v/v =1:1), was added to a solution of 1,5-dimethyltetrazole (0.5 g, 0.0051 mol) in 10 ml of the same solvent mixture. After stirring the reaction mixture at 323–333 K C for 0.5 h, the obtained light-violet crystals of (I) were filtered off, washed with methanol (2 × 5 ml), and dried in air [0.96 g, yield 84%; m.p. 633 K (decomposition)]. Calc. (%): Co 25.8, Cl 30.6. Found (%): Co 25.7, Cl 31.1. IR (cm-1): 3044 (m), 3025 (s), 2962 (m), 2938 (m), 1535 (s), 1480 (m), 1454 (w), 1409 (w), 1396 (m), 1383 (s), 1332 (s), 1265 (m), 1235 (s), 1144 (s), 1090 (w), 1060 (s), 1031 (m), 739 (s), 681 (m), 607 (w), 565 (w), 525 (w).
For complex (I), a triclinic unit cell (a = 6.728, b = 7.596, c = 8.764 Å, α = 109.62, β = 102.96, γ = 105.70°) was determined using the indexing program TREOR90 (Werner et al., 1985). The obtained values as well as observed resemblance of powder patterns indicated isotypism of (I) with investigated earlier coordination polymers CuCl2L, where L = 1,5-dimethyltetrazole, crystallizing in the space group P1 (Ivashkevich et al., 2006). This space group and the atomic coordinates of the above copper(II) complex were used as starting parameters for the Rietveld refinement of (I) with the FULLPROF program (Rodríguez-Carvajal, 2001). However, the refinement found difficulty in reaching the agreement of experimental and calculated intensities of reflections. From this fact an assumption was made that the above unit-cell dimensions were inconsistent with the initial atomic coordinates. Search for alternative unit cells resulted in the following cell: a' = 6.728, b' = 7.596, c' = 8.997 Å; α' = 108.35, β' = 107.50, γ' = 105.70°, which is of the same volume and related to the first one by the vector transformation a' =-a, b' =-b, c' = a + b + c. This cell provided a good agreement of the observed and calculated intensities.
Background intensity was found by Fourier filtering technique as implemented in the FULLPROF program, under visual inspection of the resulting background curve. Correction for profile asymmetry was made for reflections up to 2θ=25°.
The H atoms of the methyl groups were placed in geometrically calculated positions using the program SHELXL97 (Sheldrick, 2008), with displacement parameter Biso(H)=1.5Biso(C). Non-H atoms were refined isotropically. Four independent Biso parameters were employed: one for the two Co, one for the two Cl atoms, one for all N and C atoms of the tetrazole ring, and one for the C atoms of the methyl groups.
For the refinement, suitable restraints were imposed on bond lengths of the ligand molecule, based on a geometry analysis of 1,5-alkyltetrazoles (Cambridge Structural Database, version 5.29 of November 2007; Allen, 2002). The restraints were set as d(3σ), where d are mean values of bond distances resulting from a CSD survey, and σ are their s.u. values. For the refined atomic coordinates of (I), the s.u. values are taken from the software and likely to be underestimated.
The observed, calculated and difference diffraction patterns for the refined crystal structure are shown in Fig. 3 (2θ range of 11–90 ° is presented).
|[CoCl2(C3H6N4)]||V = 376.72 (4) Å3|
|Mr = 227.95||Z = 2|
|Triclinic, P1||F(000) = 226|
|Hall symbol: -P 1||Dx = 2.010 Mg m−3|
|a = 6.7159 (4) Å||Co Kα radiation, λ = 1.79021 Å|
|b = 7.5986 (4) Å||T = 295 K|
|c = 8.9231 (5) Å||Particle morphology: finely ground powder|
|α = 108.639 (2)°||light-violet|
|β = 107.259 (3)°||flat sheet, 30 × 30 mm|
|γ = 105.769 (3)°||Specimen preparation: Prepared at 295 K and 100 kPa|
|HZG-4A (Carl Zeiss, Jena) diffractometer||Data collection mode: reflection|
|Radiation source: fine-focus sealed X-ray tube, BSV-29||Scan method: step|
|Fe filtered||2θmin = 11.00°, 2θmax = 130.00°, 2θstep = 0.02°|
|Specimen mounting: packed powder pellet|
|Refinement on Inet||Profile function: psevdo-Voigt, η = 0.664(5)|
|Least-squares matrix: full with fixed elements per cycle||45 parameters|
|Rp = 0.018||7 restraints|
|Rwp = 0.024||0 constraints|
|Rexp = 0.025||H-atom parameters constrained|
|RBragg = 0.023||Weighting scheme based on measured s.u.'s|
|χ2 = 0.941||(Δ/σ)max = 0.002|
|5951 data points||Background function: Fourier filtering|
|Excluded region(s): none||Preferred orientation correction: none|
|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|
|Cl1||0.6168 (5)||0.7266 (4)||−0.1147 (4)||0.0254 (9)*|
|Cl2||−0.1025 (5)||1.1819 (4)||0.2275 (4)||0.0254 (9)*|
|N1||0.3124 (10)||0.7423 (14)||0.3267 (10)||0.032 (2)*|
|N2||0.4540 (11)||0.8008 (13)||0.2565 (10)||0.032 (2)*|
|N3||0.3888 (9)||0.8891 (13)||0.1626 (10)||0.032 (2)*|
|N4||0.1745 (10)||0.8607 (14)||0.1504 (11)||0.032 (2)*|
|C5||0.1349 (12)||0.783 (2)||0.2552 (15)||0.032 (2)*|
|C6||−0.0585 (12)||0.7367 (16)||0.2934 (13)||0.035 (3)*|
|C7||0.3895 (17)||0.6847 (16)||0.4623 (10)||0.035 (3)*|
|Co1—Cl2||2.461 (3)||N1—C5||1.341 (14)|
|Co1—N4||2.224 (10)||N1—C7||1.419 (14)|
|Co1—Cl1i||2.482 (3)||N2—N3||1.283 (13)|
|Co1—Cl2ii||2.461 (3)||N3—N4||1.361 (11)|
|Co1—N4ii||2.224 (10)||N4—C5||1.307 (17)|
|Co1—Cl1iii||2.482 (3)||C5—C6||1.421 (15)|
|Cl2—Co1—N4||95.5 (2)||Cl1iii—Co2—N3iii||94.9 (3)|
|Cl1i—Co1—Cl2||84.91 (11)||Co1iv—Cl1—Co2||85.92 (10)|
|Cl2—Co1—N4ii||84.5 (2)||N2—N1—C5||103.6 (9)|
|Cl1iii—Co1—Cl2||95.09 (11)||N2—N1—C7||118.7 (8)|
|Cl1i—Co1—N4||93.6 (3)||C5—N1—C7||137.0 (10)|
|Cl2ii—Co1—N4||84.5 (2)||N1—N2—N3||113.8 (8)|
|Cl1iii—Co1—N4||86.4 (3)||Co2—N3—N4||119.0 (7)|
|Cl1i—Co1—Cl2ii||95.09 (11)||N2—N3—N4||103.5 (8)|
|Cl1i—Co1—N4ii||86.4 (3)||Co1—N4—N3||115.1 (7)|
|Cl2ii—Co1—N4ii||95.5 (2)||N3—N4—C5||109.6 (9)|
|Cl1iii—Co1—Cl2ii||84.91 (11)||N1—C5—N4||108.8 (9)|
|Cl1iii—Co1—N4ii||93.6 (3)||N1—C5—C6||121.2 (12)|
|Cl1—Co2—N3||94.9 (3)||N4—C5—C6||130.0 (11)|
Symmetry codes: (i) x−1, y, z; (ii) −x, −y+2, −z; (iii) −x+1, −y+2, −z; (iv) x+1, y, z.
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: CV2491).