Diaqua­tetra­imidazole­cobalt(II) dibromide

In the title compound, [Co(C₃H₄N₂)₄(H₂O)₂]Br₂, the Co atom is situated on an inversion center. It is coordinated by four N atoms of four imidazole ligands and two O atoms of water mol­ecules and has an octa­hedral geometry. In the crystal structure, water mol­ecules, imidazole NH groups and Br atoms contribute to the formation of a three-dimensional hydrogen-bonded network.

Key indicators

• Single-crystal X-ray study
• T = 223 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.021
• wR factor = 0.050
• Data-to-parameter ratio = 19.6

checkCIF/PLATON results

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   1 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
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Computing details

Data collection: SMART (Bruker, 1998); cell refinement: SAINT (Bruker, 1998); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 1997); program(s) used to refine structure: SHELXTL; molecular graphics: ORTEP-3 (Farrugia, 1997) and DIAMOND (Brandenburg & Berndt, 1999); software used to prepare material for publication: SHELXTL.

Diaquatetraimidazolecobalt(II) dibromide

Crystal data

[Co(C3H4N2)4(H2O)2]Br2	F(000) = 1044
Mr = 527.11	Dx = 1.833 Mg m^−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2yc	Cell parameters from 12889 reflections
a = 12.6213 (18) Å	θ = 2.5–28.3°
b = 11.2582 (16) Å	µ = 5.11 mm^−1
c = 14.291 (2) Å	T = 223 K
β = 109.869 (3)°	Prism, pink
V = 1909.7 (5) Å^3	0.30 × 0.25 × 0.19 mm
Z = 4

Data collection

Bruker AXS APEX CCD diffractometer	2377 independent reflections
Radiation source: fine-focus sealed tube	2121 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.030
ω scans	θmax = 28.3°, θmin = 2.5°
Absorption correction: multi-scan (SADABS in SAINT; Bruker 1998)	h = −16→16
Tmin = 0.24, Tmax = 0.38	k = −14→14
12889 measured reflections	l = −18→18

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.021	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.050	H atoms treated by a mixture of independent and constrained refinement
S = 1.09	w = 1/[σ^2(Fo^2) + (0.0204P)^2 + 1.4558P] where P = (Fo^2 + 2Fc^2)/3
2377 reflections	(Δ/σ)max < 0.001
121 parameters	Δρmax = 0.32 e Å^−3
0 restraints	Δρmin = −0.46 e Å^−3

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 F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Co1	0.2500	0.2500	0.5000	0.01799 (8)
Br1	0.091545 (16)	0.841575 (15)	0.424733 (14)	0.02899 (7)
N1	0.23556 (12)	0.19848 (13)	0.35015 (10)	0.0224 (3)
N2	0.12210 (12)	0.37761 (13)	0.44040 (11)	0.0225 (3)
N3	0.25328 (14)	0.20284 (15)	0.20214 (11)	0.0309 (3)
H3	0.2748	0.2250	0.1539	0.037*
N4	0.03271 (14)	0.54726 (14)	0.40045 (12)	0.0316 (4)
H4	0.0198	0.6224	0.3980	0.038*
C5	0.17302 (15)	0.10756 (16)	0.29228 (13)	0.0263 (4)
H5	0.1301	0.0531	0.3129	0.032*
C6	0.18363 (17)	0.10958 (17)	0.20087 (14)	0.0308 (4)
H6	0.1503	0.0580	0.1482	0.037*
C7	0.28206 (16)	0.25358 (17)	0.29232 (14)	0.0283 (4)
H7	0.3290	0.3194	0.3117	0.034*
C8	0.12905 (16)	0.49382 (16)	0.45272 (15)	0.0290 (4)
H8	0.1930	0.5335	0.4928	0.035*
C9	−0.04161 (16)	0.46135 (18)	0.35164 (15)	0.0334 (4)
H9	−0.1156	0.4722	0.3098	0.040*
C10	0.01404 (16)	0.35711 (16)	0.37628 (14)	0.0285 (4)
H10	−0.0159	0.2828	0.3535	0.034*
O1	0.12216 (12)	0.12080 (12)	0.49856 (11)	0.0289 (3)
H1	0.067 (2)	0.138 (2)	0.5134 (17)	0.035*
H2	0.1149 (19)	0.056 (2)	0.4817 (17)	0.035*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Co1	0.02037 (15)	0.01513 (15)	0.02075 (15)	0.00013 (12)	0.00997 (12)	−0.00093 (11)
Br1	0.03111 (11)	0.02206 (10)	0.04069 (12)	−0.00521 (7)	0.02115 (8)	−0.00743 (7)
N1	0.0252 (7)	0.0223 (7)	0.0218 (7)	0.0012 (6)	0.0107 (6)	0.0001 (6)
N2	0.0227 (7)	0.0200 (7)	0.0257 (7)	0.0005 (6)	0.0094 (6)	−0.0016 (6)
N3	0.0398 (9)	0.0352 (9)	0.0235 (8)	0.0025 (7)	0.0181 (7)	0.0044 (7)
N4	0.0335 (8)	0.0180 (7)	0.0444 (9)	0.0062 (6)	0.0149 (7)	0.0030 (7)
C5	0.0320 (9)	0.0227 (8)	0.0248 (9)	−0.0035 (7)	0.0103 (7)	−0.0008 (7)
C6	0.0397 (11)	0.0276 (9)	0.0239 (9)	0.0012 (8)	0.0094 (8)	−0.0022 (7)
C7	0.0321 (9)	0.0262 (9)	0.0298 (9)	−0.0031 (8)	0.0145 (7)	0.0011 (7)
C8	0.0260 (9)	0.0221 (9)	0.0388 (10)	−0.0015 (7)	0.0108 (8)	−0.0045 (7)
C9	0.0268 (9)	0.0319 (10)	0.0362 (10)	0.0051 (8)	0.0039 (8)	0.0012 (8)
C10	0.0278 (9)	0.0224 (9)	0.0322 (9)	−0.0017 (7)	0.0063 (8)	−0.0029 (7)
O1	0.0296 (7)	0.0194 (6)	0.0461 (8)	−0.0044 (5)	0.0236 (6)	−0.0073 (6)

Geometric parameters (Å, º)

Co1—N2	2.1120 (15)	N4—C8	1.335 (2)
Co1—N2^i	2.1120 (15)	N4—C9	1.363 (3)
Co1—N1	2.1657 (14)	N4—H4	0.8600
Co1—N1^i	2.1657 (14)	C5—C6	1.358 (2)
Co1—O1^i	2.1672 (13)	C5—H5	0.9300
Co1—O1	2.1672 (13)	C6—H6	0.9300
N1—C7	1.320 (2)	C7—H7	0.9300
N1—C5	1.382 (2)	C8—H8	0.9300
N2—C8	1.319 (2)	C9—C10	1.351 (3)
N2—C10	1.380 (2)	C9—H9	0.9300
N3—C7	1.342 (2)	C10—H10	0.9300
N3—C6	1.366 (3)	O1—H1	0.82 (2)
N3—H3	0.8600	O1—H2	0.76 (2)
N2—Co1—N2^i	180.00 (8)	C8—N4—C9	107.71 (16)
N2—Co1—N1	89.28 (5)	C8—N4—H4	126.1
N2^i—Co1—N1	90.72 (5)	C9—N4—H4	126.1
N2—Co1—N1^i	90.72 (5)	C6—C5—N1	109.89 (16)
N2^i—Co1—N1^i	89.28 (5)	C6—C5—H5	125.1
N1—Co1—N1^i	180.0	N1—C5—H5	125.1
N2—Co1—O1^i	90.68 (6)	C5—C6—N3	105.87 (16)
N2^i—Co1—O1^i	89.32 (6)	C5—C6—H6	127.1
N1—Co1—O1^i	90.08 (5)	N3—C6—H6	127.1
N1^i—Co1—O1^i	89.92 (5)	N1—C7—N3	111.62 (16)
N2—Co1—O1	89.32 (6)	N1—C7—H7	124.2
N2^i—Co1—O1	90.68 (6)	N3—C7—H7	124.2
N1—Co1—O1	89.92 (5)	N2—C8—N4	111.46 (17)
N1^i—Co1—O1	90.08 (5)	N2—C8—H8	124.3
O1^i—Co1—O1	180.00 (7)	N4—C8—H8	124.3
C7—N1—C5	104.97 (14)	C10—C9—N4	106.06 (16)
C7—N1—Co1	125.97 (12)	C10—C9—H9	127.0
C5—N1—Co1	128.97 (12)	N4—C9—H9	127.0
C8—N2—C10	105.10 (15)	C9—C10—N2	109.67 (16)
C8—N2—Co1	127.86 (13)	C9—C10—H10	125.2
C10—N2—Co1	126.98 (12)	N2—C10—H10	125.2
C7—N3—C6	107.64 (15)	Co1—O1—H1	122.1 (16)
C7—N3—H3	126.2	Co1—O1—H2	130.7 (17)
C6—N3—H3	126.2	H1—O1—H2	107 (2)

Symmetry code: (i) −x+1/2, −y+1/2, −z+1.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H2···Br1^ii	0.76 (2)	2.54 (3)	3.2965 (14)	180 (2)
O1—H1···Br1^iii	0.82 (2)	2.46 (2)	3.2659 (14)	170 (2)
N4—H4···Br1	0.86	2.61	3.3875 (16)	151
N3—H3···Br1^iv	0.86	2.67	3.4607 (16)	154

Symmetry codes: (ii) x, y−1, z; (iii) −x, −y+1, −z+1; (iv) −x+1/2, y−1/2, −z+1/2.