Bis(2,6-dimethyl-pyridinium) tetra-bromido-cobaltate(II).

In the crystal structure of the title compound, (C(7)H(10)N)(2)[CoBr(4)], the [CoBr(4)](2-) anion is connected to two cations through N-H⋯Br and H(2)C-H⋯Br hydrogen bonds to form two-dimensional cation-anion-cation layers normal to the crystallographic b axis. Inter-actions of the π-π type are absent between cations in the stacks [centroid-centroid separation = 5.01 (5) Å]. Significant inter-molecular Br-aryl inter-actions are present in the structure, especially an unusually short Br-ring centroid inter-action of 3.78 (1) Å. The coordination geometry of the anion is approximately tetrahedral and a twofold rotation axis passes through the Co atom.

Related literature

For general background, see: Al-Far & Ali (2007a ▶,b ▶); Ali & Al-Far (2007 ▶); Allen et al. (1997 ▶); Desiraju & Steiner (1999 ▶); Dolling et al. (2001 ▶); Hunter (1994 ▶); Panunto et al. (1987 ▶); Robinson et al. (2000 ▶). For related literature, see: Al-Far & Ali (2008 ▶); Ali & Al-Far (2008 ▶); Allen et al. (1987 ▶); Desiraju (1997 ▶); Zhang et al. (2005 ▶).

Experimental

Crystal data

(C7H10N)2[CoBr4]

M = 594.89

Orthorhombic,

a = 17.234 (2) Å

b = 9.0691 (10) Å

c = 13.729 (2) Å

V = 2145.7 (5) Å3

Z = 4

Mo Kα radiation

μ = 8.24 mm−1

T = 293 (2) K

0.40 × 0.30 × 0.20 mm

Data collection

Bruker P4 diffractometer

Absorption correction: ψ scan;(North et al., 1968 ▶) T min = 0.064, T max = 0.192

2534 measured reflections

1930 independent reflections

885 reflections with I > 2σ(I)

R int = 0.072

Refinement

R[F 2 > 2σ(F 2)] = 0.055

wR(F 2) = 0.117

S = 0.97

1930 reflections

97 parameters

H-atom parameters constrained

Δρmax = 0.55 e Å−3

Δρmin = −0.40 e Å−3

Data collection: XSCANS (Siemens, 1996 ▶); cell refinement: XSCANS; data reduction: SHELXTL (Sheldrick, 2008 ▶); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Crystal structure: contains datablocks I, global. DOI: 10.1107/S160053680800439X/at2543sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S160053680800439X/at2543Isup2.hkl

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

(C7H10N)2[CoBr4]	F000 = 1140
Mr = 594.89	Dx = 1.842 Mg m−3
Orthorhombic, Pbcn	Mo Kα radiation λ = 0.71073 Å
Hall symbol: -P 2n 2ab	Cell parameters from 36 reflections
a = 17.234 (2) Å	θ = 2.4–16.8º
b = 9.0691 (10) Å	µ = 8.24 mm−1
c = 13.729 (2) Å	T = 293 (2) K
V = 2145.7 (5) Å3	Chunk, blue
Z = 4	0.40 × 0.30 × 0.20 mm

Bruker P4 diffractometer	1930 independent reflections
Radiation source: fine-focus sealed tube	885 reflections with I > 2σ(I)
Monochromator: graphite	Rint = 0.072
Detector resolution: 3 pixels mm-1	θmax = 25.2º
T = 293(2) K	θmin = 2.4º
ω Scans scans	h = −1→20
Absorption correction: ψ scan(North et al., 1968)	k = −1→10
Tmin = 0.064, Tmax = 0.192	l = −16→1
2534 measured reflections

Refinement on F2	Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: full	H-atom parameters constrained
R[F2 > 2σ(F2)] = 0.055	w = 1/[σ2(Fo2) + (0.0321P)2] where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.117	(Δ/σ)max < 0.001
S = 0.97	Δρmax = 0.55 e Å−3
1930 reflections	Δρmin = −0.40 e Å−3
97 parameters	Extinction correction: SHELXL97, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0060 (4)
Secondary atom site location: difference Fourier map

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.

	x	y	z	Uiso*/Ueq
Br1	0.39353 (5)	−0.42729 (12)	0.18719 (7)	0.0680 (4)
Co1	0.5000	−0.2856 (2)	0.2500	0.0500 (6)
Br2	0.45145 (6)	−0.13081 (14)	0.37845 (7)	0.0845 (5)
N1	0.6230 (4)	−0.1559 (9)	0.4945 (5)	0.056 (2)
H1	0.5806	−0.1498	0.4618	0.067*
C2	0.6211 (6)	−0.2366 (13)	0.5769 (8)	0.071 (3)
C3	0.6900 (8)	−0.2499 (13)	0.6250 (9)	0.097 (4)
H3	0.6928	−0.3052	0.6819	0.116*
C4	0.7556 (7)	−0.1811 (15)	0.5891 (10)	0.099 (4)
H4	0.8025	−0.1918	0.6218	0.119*
C5	0.7527 (6)	−0.0991 (13)	0.5078 (8)	0.085 (4)
H5	0.7973	−0.0526	0.4852	0.102*
C6	0.6850 (6)	−0.0840 (11)	0.4588 (6)	0.061 (3)
C7	0.5478 (6)	−0.3092 (14)	0.6029 (8)	0.116 (5)
H7A	0.5083	−0.2813	0.5572	0.174*
H7B	0.5325	−0.2795	0.6672	0.174*
H7C	0.5546	−0.4142	0.6012	0.174*
C8	0.6727 (5)	0.0072 (13)	0.3689 (7)	0.106 (4)
H8A	0.6197	−0.0011	0.3483	0.159*
H8B	0.7063	−0.0274	0.3180	0.159*
H8C	0.6843	0.1086	0.3829	0.159*

	U11	U22	U33	U12	U13	U23
Br1	0.0521 (6)	0.0757 (8)	0.0762 (7)	−0.0135 (6)	−0.0140 (6)	0.0045 (6)
Co1	0.0379 (9)	0.0594 (14)	0.0527 (10)	0.000	−0.0008 (9)	0.000
Br2	0.0537 (6)	0.1130 (11)	0.0867 (8)	0.0146 (7)	−0.0040 (6)	−0.0405 (7)
N1	0.036 (4)	0.069 (6)	0.063 (5)	−0.006 (4)	0.001 (4)	−0.005 (5)
C2	0.056 (7)	0.081 (8)	0.075 (7)	−0.007 (6)	−0.003 (6)	0.018 (7)
C3	0.106 (10)	0.080 (10)	0.103 (9)	0.013 (8)	−0.024 (9)	0.009 (8)
C4	0.065 (8)	0.116 (12)	0.117 (11)	0.032 (9)	−0.045 (8)	−0.020 (9)
C5	0.055 (7)	0.113 (11)	0.087 (8)	0.006 (7)	−0.012 (7)	−0.007 (8)
C6	0.050 (6)	0.068 (7)	0.065 (7)	−0.014 (6)	0.005 (5)	−0.017 (6)
C7	0.104 (10)	0.124 (12)	0.120 (9)	−0.034 (9)	0.006 (8)	0.055 (9)
C8	0.085 (8)	0.150 (13)	0.082 (8)	−0.045 (9)	0.002 (7)	0.040 (9)

Br1—Co1	2.4002 (13)	C4—C5	1.341 (15)
Co1—Br1i	2.4002 (13)	C4—H4	0.9300
Co1—Br2	2.4044 (15)	C5—C6	1.354 (12)
Co1—Br2i	2.4044 (15)	C5—H5	0.9300
N1—C2	1.348 (11)	C6—C8	1.501 (12)
N1—C6	1.345 (10)	C7—H7A	0.9600
N1—H1	0.8600	C7—H7B	0.9600
C2—C3	1.363 (13)	C7—H7C	0.9600
C2—C7	1.468 (12)	C8—H8A	0.9600
C3—C4	1.383 (15)	C8—H8B	0.9600
C3—H3	0.9300	C8—H8C	0.9600
Br1—Co1—Br1i	115.28 (9)	C4—C5—C6	120.1 (12)
Br1—Co1—Br2	108.06 (3)	C4—C5—H5	119.9
Br1i—Co1—Br2	108.37 (4)	C6—C5—H5	119.9
Br1—Co1—Br2i	108.37 (4)	N1—C6—C5	117.0 (10)
Br1i—Co1—Br2i	108.06 (3)	N1—C6—C8	117.1 (9)
Br2—Co1—Br2i	108.54 (9)	C5—C6—C8	125.9 (10)
C2—N1—C6	126.0 (8)	C2—C7—H7A	109.5
C2—N1—H1	117.0	C2—C7—H7B	109.5
C6—N1—H1	117.0	H7A—C7—H7B	109.5
N1—C2—C3	115.7 (10)	C2—C7—H7C	109.5
N1—C2—C7	117.9 (9)	H7A—C7—H7C	109.5
C3—C2—C7	126.3 (11)	H7B—C7—H7C	109.5
C2—C3—C4	120.0 (11)	C6—C8—H8A	109.5
C2—C3—H3	120.0	C6—C8—H8B	109.5
C4—C3—H3	120.0	H8A—C8—H8B	109.5
C5—C4—C3	121.1 (11)	C6—C8—H8C	109.5
C5—C4—H4	119.5	H8A—C8—H8C	109.5
C3—C4—H4	119.5	H8B—C8—H8C	109.5
C6—N1—C2—C3	−2.9 (16)	C3—C4—C5—C6	−1(2)
C6—N1—C2—C7	−178.9 (10)	C2—N1—C6—C5	3.0 (15)
N1—C2—C3—C4	0.8 (18)	C2—N1—C6—C8	−176.3 (9)
C7—C2—C3—C4	176.5 (12)	C4—C5—C6—N1	−1.0 (16)
C2—C3—C4—C5	1(2)	C4—C5—C6—C8	178.2 (11)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···Br2	0.86	2.51	3.366 (7)	176
C7—H7A···Br2	0.96	2.97	3.856 (10)	153

Br1—Co1	2.4002 (13)
Co1—Br2	2.4044 (15)

Br1—Co1—Br1i	115.28 (9)
Br1—Co1—Br2	108.06 (3)
Br1—Co1—Br2i	108.37 (4)
Br2—Co1—Br2i	108.54 (9)

Symmetry code: (i) .

Table 2

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1⋯Br2	0.86	2.51	3.366 (7)	176
C7—H7A⋯Br2	0.96	2.97	3.856 (10)	153