Dibromidotetra­kis(1H-indazole-κN2)copper(II)

Hossaini Sadr, M.; Soltani, B.; Gao, S.; Ng, S.W.

doi:10.1107/S1600536807062940

metal-organic compounds

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ISSN: 2056-9890

Volume 64| Part 1| January 2008| Page m109

https://doi.org/10.1107/S1600536807062940

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Dibromidotetrakis(1H-indazole-κN²)copper(II)

Moayad Hossaini Sadr,^a Behzad Soltani,^a Shan Gao ^b and Seik Weng Ng ^c ^*

^aDepartment of Chemistry, Azarbaijan University of Tarbiat Moallem, Tabriz, Iran, ^bSchool of Chemistry and Materials Science, Heilongjiang University, Harbin 150080, People's Republic of China, and ^cDepartment of Chemistry, University of Malaya, 50603 Kuala Lumpur, Malaysia
^*Correspondence e-mail: seikweng@um.edu.my

(Received 22 November 2007; accepted 24 November 2007; online 6 December 2007)

The Cu atom in the title compound, [CuBr₂(C₇H₆N₂)₄], is surrounded by four N-heterocycles that define an N₄ square-planar geometry. The coordination geometry is distorted towards an elongated octahedron owing to the presence of the two Br⁻ anions, which are located at about 3 Å above and below the square plane. There are two independent molecules in the asymmetric unit, each with their Cu atom lying on an inversion centre.

Related literature

For related structures, see Hossaini Sadr et al. (2004 , 2005 , 2006 ). For related literature, see: Allen (2002 ).

Experimental

Crystal data

[CuBr₂(C₇H₆N₂)₄]
M_r = 695.91
Triclinic, $[P \overline 1]$
a = 10.338 (1) Å
b = 10.923 (1) Å
c = 13.730 (1) Å
α = 72.545 (3)°
β = 77.329 (3)°
γ = 73.890 (3)°
V = 1405.3 (3) Å³
Z = 2
Mo Kα radiation
μ = 3.65 mm⁻¹
T = 295 (2) K
0.24 × 0.21 × 0.12 mm

Data collection

Rigaku R-AXIS RAPID diffractometer
Absorption correction: multi-scan (ABSCOR; Higashi, 1995 ) T_min = 0.073, T_max = 0.668
13779 measured reflections
6389 independent reflections
2895 reflections with I > 2σ(I)
R_int = 0.046

Refinement

R[F² > 2σ(F²)] = 0.061
wR(F²) = 0.228
S = 1.13
6389 reflections
356 parameters
12 restraints
H-atom parameters constrained
Δρ_max = 0.65 e Å⁻³
Δρ_min = −1.00 e Å⁻³

Table 1
Selected bond lengths (Å)

Cu1—N1	2.027 (5)
Cu1—N3	2.008 (6)
Cu1—Br1	3.033 (1)
Cu2—N5	2.024 (7)
Cu2—N7	2.023 (6)
Cu2—Br2	2.980 (1)

Data collection: RAPID-AUTO (Rigaku Corporation, 1998 ); cell refinement: RAPID-AUTO; data reduction: CrystalStructure (Rigaku/MSC, 2002 ); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: X-SEED (Barbour, 2001 ); software used to prepare material for publication: publCIF (Westrip, 2007 ).

Supporting information

Crystal structure: contains datablocks global, I. DOI: https://doi.org/10.1107/S1600536807062940/tk2226sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536807062940/tk2226Isup2.hkl

checkCIF report

Comment top

Unlike benzimidazole, which affords a number of adducts with metal salts, indazole furnishes only few complexes (Cambridge Structural Database, Version 5.28; Allen, 2002). The present study of the copper dibromide adduct (I) follows previous studies on Cu complexes of pyrazole-based N-heterocycles (Hossaini Sadr et al., 2005; 2006).

Two independent [Cu(C₇H₆N₂)₄]²⁺2Br^- formula units comprise the asymmetric unit in (I), each with the Cu atom situated on a center of inversion. Complex (I) is formally a salt (Fig. 1) owing to the large distance of the Br ions (more than 3 Å) above and below the N₄ square plane defined by the four N-heterocycles. In the corresponding imidazole adduct, one Br atom is covalently bonded whereas the other is uncoordinated, so that the geometry is a square pyramid (Hossaini Sadr et al., 2004).

Related literature top

For related structures, see Hossaini Sadr et al. (2004, 2005, 2006). For related literature, see: Allen (2002).

Experimental top

Copper dibromide (0.05 g, 0.25 mmol) and indazole (0.12 g, 1 mmol) were dissolved in acetone (25 ml). Slow evapoaration of the filtered solution yielded crystals.

Structure description top

For related structures, see Hossaini Sadr et al. (2004, 2005, 2006). For related literature, see: Allen (2002).

Computing details top

Data collection: RAPID-AUTO (Rigaku Corporation, 1998); cell refinement: RAPID-AUTO (Rigaku Corporation, 1998); data reduction: CrystalStructure (Rigaku/MSC, 2002); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: X-SEED (Barbour, 2001); software used to prepare material for publication: publCIF (Westrip, 2007).

Figures top

Fig. 1. Molecular structures of the two independent molecules of [Cu(C₇H₆N₂)₄]²⁺ 2Br^- (I) showing displacement ellipsoids at the 50% probability level and H atoms as spheres of arbitrary radius. Each of the Cu atoms is located on a crystallographic center of inversion. The Cu···Br interactions are denoted by dashed lines.

Dibromidotetrakis(1H-indazole-κN²)copper(II) top

Crystal data top

[CuBr₂(C₇H₆N₂)₄]	Z = 2
M_r = 695.91	F(000) = 694
Triclinic, P1	D_x = 1.645 Mg m⁻³
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 10.338 (1) Å	Cell parameters from 7166 reflections
b = 10.923 (1) Å	θ = 3.2–27.5°
c = 13.730 (1) Å	µ = 3.65 mm⁻¹
α = 72.545 (3)°	T = 295 K
β = 77.329 (3)°	Prism, blue
γ = 73.890 (3)°	0.24 × 0.21 × 0.12 mm
V = 1405.3 (3) Å³

Data collection top

Rigaku R-AXIS RAPID diffractometer	6389 independent reflections
Radiation source: fine-focus sealed tube	2895 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.046
Detector resolution: 10.000 pixels mm^-1	θ_max = 27.5°, θ_min = 3.2°
ω scans	h = −13→13
Absorption correction: multi-scan (ABSCOR; Higashi, 1995)	k = −11→14
T_min = 0.073, T_max = 0.668	l = −17→17
13779 measured reflections

Refinement top

Refinement on F²	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F² > 2σ(F²)] = 0.061	H-atom parameters constrained
wR(F²) = 0.228	w = 1/[σ²(F_o²) + (0.1018P)² + 0.0608P] where P = (F_o² + 2F_c²)/3
S = 1.13	(Δ/σ)_max = 0.001
6389 reflections	Δρ_max = 0.65 e Å⁻³
356 parameters	Δρ_min = −1.00 e Å⁻³
12 restraints	Extinction correction: SHELXL97 (Sheldrick, 1997), Fc^*=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.008 (2)

Crystal data top

[CuBr₂(C₇H₆N₂)₄]	γ = 73.890 (3)°
M_r = 695.91	V = 1405.3 (3) Å³
Triclinic, P1	Z = 2
a = 10.338 (1) Å	Mo Kα radiation
b = 10.923 (1) Å	µ = 3.65 mm⁻¹
c = 13.730 (1) Å	T = 295 K
α = 72.545 (3)°	0.24 × 0.21 × 0.12 mm
β = 77.329 (3)°

Data collection top

Rigaku R-AXIS RAPID diffractometer	6389 independent reflections
Absorption correction: multi-scan (ABSCOR; Higashi, 1995)	2895 reflections with I > 2σ(I)
T_min = 0.073, T_max = 0.668	R_int = 0.046
13779 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.061	12 restraints
wR(F²) = 0.228	H-atom parameters constrained
S = 1.13	Δρ_max = 0.65 e Å⁻³
6389 reflections	Δρ_min = −1.00 e Å⁻³
356 parameters

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
Br1	0.62566 (10)	0.25866 (8)	0.41676 (7)	0.1011 (4)
Br2	−0.25176 (8)	0.40169 (7)	1.09777 (6)	0.0840 (3)
Cu1	0.5000	0.5000	0.5000	0.0843 (5)
Cu2	0.0000	0.5000	1.0000	0.1230 (8)
N1	0.5411 (5)	0.3924 (6)	0.6427 (4)	0.0636 (14)
N2	0.5199 (6)	0.4347 (6)	0.7267 (5)	0.0774 (16)
H2N	0.4877	0.5155	0.7291	0.093*
N3	0.3196 (6)	0.4493 (7)	0.5367 (4)	0.0748 (17)
N4	0.2108 (6)	0.5102 (6)	0.5891 (5)	0.0803 (17)
H4N	0.2071	0.5797	0.6078	0.096*
N5	0.0567 (9)	0.3532 (6)	0.9272 (5)	0.093 (2)
N6	0.1763 (9)	0.3169 (7)	0.8743 (6)	0.100 (2)
H6N	0.2408	0.3579	0.8604	0.120*
N7	−0.0951 (9)	0.6246 (6)	0.8816 (5)	0.090 (2)
N8	−0.0317 (7)	0.7102 (6)	0.8075 (5)	0.0885 (19)
H8N	0.0514	0.7141	0.8031	0.106*
C1	0.5920 (6)	0.2639 (6)	0.6683 (4)	0.0569 (15)
H1	0.6170	0.2106	0.6226	0.068*
C2	0.6029 (6)	0.2195 (6)	0.7719 (5)	0.0591 (15)
C3	0.6478 (8)	0.0951 (8)	0.8374 (6)	0.084 (2)
H3	0.6801	0.0206	0.8120	0.101*
C4	0.6428 (7)	0.0863 (9)	0.9382 (6)	0.090 (3)
H4	0.6683	0.0038	0.9828	0.108*
C5	0.6006 (8)	0.1974 (10)	0.9777 (6)	0.091 (3)
H5	0.6017	0.1881	1.0471	0.109*
C6	0.5577 (7)	0.3201 (9)	0.9148 (6)	0.086 (2)
H6	0.5296	0.3945	0.9404	0.103*
C7	0.5573 (6)	0.3298 (6)	0.8111 (4)	0.0592 (15)
C8	0.2874 (6)	0.3499 (7)	0.5225 (5)	0.0630 (16)
H8	0.3460	0.2906	0.4871	0.076*
C9	0.1562 (6)	0.3431 (7)	0.5663 (4)	0.0604 (16)
C10	0.0743 (8)	0.2577 (8)	0.5751 (6)	0.086 (2)
H10	0.1071	0.1862	0.5461	0.104*
C11	−0.0530 (8)	0.2800 (9)	0.6261 (7)	0.091 (2)
H11	−0.1082	0.2229	0.6327	0.109*
C12	−0.1034 (7)	0.3866 (9)	0.6692 (6)	0.084 (2)
H12	−0.1923	0.4004	0.7035	0.101*
C13	−0.0257 (7)	0.4712 (8)	0.6621 (6)	0.0763 (19)
H13	−0.0599	0.5420	0.6919	0.092*
C14	0.1048 (6)	0.4501 (6)	0.6102 (5)	0.0581 (15)
C15	−0.0112 (7)	0.2676 (7)	0.9321 (5)	0.0622 (16)
H15	−0.1001	0.2704	0.9658	0.075*
C16	0.0607 (6)	0.1736 (6)	0.8832 (5)	0.0578 (15)
C17	0.0283 (10)	0.0657 (9)	0.8687 (7)	0.096 (3)
H17	−0.0571	0.0472	0.8945	0.116*
C18	0.1251 (14)	−0.0105 (9)	0.8162 (8)	0.108 (3)
H18	0.1061	−0.0843	0.8069	0.130*
C19	0.2487 (11)	0.0154 (10)	0.7764 (7)	0.104 (3)
H19	0.3122	−0.0410	0.7408	0.124*
C20	0.2836 (7)	0.1224 (9)	0.7868 (6)	0.088 (2)
H20	0.3684	0.1409	0.7577	0.105*
C21	0.1863 (6)	0.2026 (6)	0.8430 (4)	0.0564 (14)
C22	−0.2200 (10)	0.6462 (7)	0.8630 (6)	0.086 (2)
H22	−0.2851	0.5999	0.9022	0.103*
C23	−0.2393 (9)	0.7522 (7)	0.7731 (6)	0.080 (2)
C24	−0.3451 (10)	0.8178 (9)	0.7148 (8)	0.103 (3)
H24	−0.4286	0.7942	0.7328	0.124*
C25	−0.3207 (13)	0.9197 (9)	0.6288 (7)	0.112 (3)
H25	−0.3900	0.9653	0.5893	0.135*
C26	−0.1982 (13)	0.9552 (10)	0.6004 (7)	0.113 (3)
H26	−0.1866	1.0240	0.5423	0.135*
C27	−0.0951 (11)	0.8941 (8)	0.6536 (6)	0.104 (3)
H27	−0.0121	0.9187	0.6346	0.124*
C28	−0.1185 (9)	0.7895 (7)	0.7408 (6)	0.080 (2)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Br1	0.1416 (8)	0.0637 (6)	0.0882 (6)	0.0001 (5)	−0.0230 (5)	−0.0221 (4)
Br2	0.0917 (6)	0.0649 (5)	0.0874 (6)	−0.0117 (4)	−0.0083 (4)	−0.0166 (4)
Cu1	0.0608 (7)	0.1132 (11)	0.0637 (7)	−0.0366 (7)	−0.0251 (6)	0.0265 (7)
Cu2	0.232 (2)	0.0513 (8)	0.0766 (8)	0.0341 (10)	−0.0776 (11)	−0.0246 (6)
N1	0.054 (3)	0.085 (4)	0.051 (3)	−0.021 (3)	−0.012 (2)	−0.007 (3)
N2	0.070 (3)	0.069 (4)	0.083 (4)	−0.011 (3)	−0.020 (3)	−0.003 (3)
N3	0.064 (3)	0.086 (5)	0.057 (3)	−0.012 (3)	−0.015 (3)	0.007 (3)
N4	0.087 (4)	0.073 (4)	0.080 (4)	−0.021 (3)	−0.021 (3)	−0.011 (3)
N5	0.134 (6)	0.056 (4)	0.067 (4)	0.023 (4)	−0.027 (4)	−0.016 (3)
N6	0.151 (7)	0.067 (4)	0.097 (5)	−0.041 (5)	−0.055 (5)	−0.002 (4)
N7	0.151 (6)	0.042 (3)	0.072 (4)	0.002 (4)	−0.044 (4)	−0.010 (3)
N8	0.122 (5)	0.058 (4)	0.089 (4)	−0.008 (4)	−0.050 (4)	−0.011 (3)
C1	0.064 (3)	0.054 (4)	0.045 (3)	−0.007 (3)	−0.014 (3)	−0.004 (3)
C2	0.058 (3)	0.056 (4)	0.058 (3)	−0.009 (3)	−0.009 (3)	−0.011 (3)
C3	0.097 (5)	0.059 (4)	0.084 (5)	−0.008 (4)	−0.021 (4)	−0.005 (4)
C4	0.077 (5)	0.095 (6)	0.070 (5)	−0.010 (4)	−0.021 (4)	0.018 (4)
C5	0.083 (5)	0.121 (8)	0.055 (4)	−0.018 (5)	−0.016 (4)	−0.005 (5)
C6	0.078 (5)	0.100 (6)	0.072 (5)	−0.009 (4)	−0.011 (4)	−0.023 (4)
C7	0.055 (3)	0.069 (4)	0.047 (3)	−0.013 (3)	−0.009 (3)	−0.004 (3)
C8	0.051 (3)	0.066 (4)	0.063 (4)	−0.004 (3)	−0.003 (3)	−0.017 (3)
C9	0.051 (3)	0.073 (4)	0.053 (3)	−0.018 (3)	−0.009 (3)	−0.006 (3)
C10	0.084 (5)	0.081 (5)	0.103 (6)	−0.026 (4)	−0.009 (4)	−0.034 (4)
C11	0.076 (5)	0.098 (7)	0.106 (6)	−0.042 (5)	−0.028 (5)	−0.005 (5)
C12	0.059 (4)	0.092 (6)	0.079 (5)	−0.015 (4)	−0.001 (4)	0.002 (4)
C13	0.068 (4)	0.070 (5)	0.082 (5)	−0.005 (4)	−0.006 (4)	−0.020 (4)
C14	0.049 (3)	0.063 (4)	0.060 (3)	−0.025 (3)	−0.007 (3)	0.000 (3)
C15	0.062 (4)	0.061 (4)	0.056 (3)	0.000 (3)	−0.006 (3)	−0.017 (3)
C16	0.059 (3)	0.052 (4)	0.057 (3)	−0.010 (3)	−0.013 (3)	−0.006 (3)
C17	0.118 (6)	0.086 (6)	0.096 (6)	−0.060 (6)	−0.028 (5)	0.001 (5)
C18	0.166 (10)	0.056 (5)	0.117 (8)	−0.011 (6)	−0.058 (8)	−0.029 (5)
C19	0.123 (8)	0.086 (7)	0.094 (6)	0.031 (6)	−0.044 (6)	−0.042 (5)
C20	0.065 (4)	0.117 (7)	0.077 (5)	−0.011 (4)	−0.011 (4)	−0.026 (5)
C21	0.072 (4)	0.044 (3)	0.054 (3)	−0.011 (3)	−0.016 (3)	−0.012 (3)
C22	0.120 (7)	0.055 (5)	0.073 (5)	0.004 (4)	−0.014 (5)	−0.023 (4)
C23	0.112 (6)	0.055 (4)	0.068 (4)	0.009 (4)	−0.030 (4)	−0.022 (3)
C24	0.106 (6)	0.098 (7)	0.104 (6)	0.011 (5)	−0.028 (5)	−0.045 (5)
C25	0.153 (9)	0.082 (7)	0.087 (6)	0.032 (6)	−0.064 (7)	−0.020 (5)
C26	0.161 (10)	0.084 (7)	0.074 (5)	0.010 (7)	−0.030 (7)	−0.020 (5)
C27	0.156 (8)	0.059 (5)	0.087 (5)	−0.005 (5)	−0.038 (6)	−0.009 (4)
C28	0.118 (6)	0.050 (4)	0.069 (4)	−0.003 (4)	−0.035 (4)	−0.012 (3)

Geometric parameters (Å, º) top

Cu1—N1	2.027 (5)	C6—H6	0.9300
Cu1—N3	2.008 (6)	C8—C9	1.370 (8)
Cu1—Br1	3.033 (1)	C8—H8	0.9300
Cu2—N5	2.024 (7)	C9—C10	1.389 (10)
Cu2—N7	2.023 (6)	C9—C14	1.395 (9)
Cu2—Br2	2.980 (1)	C10—C11	1.342 (11)
Cu1—N3ⁱ	2.008 (6)	C10—H10	0.9300
Cu1—N1ⁱ	2.027 (5)	C11—C12	1.385 (12)
Cu2—N7ⁱⁱ	2.023 (6)	C11—H11	0.9300
Cu2—N5ⁱⁱ	2.024 (7)	C12—C13	1.354 (12)
N1—N2	1.320 (8)	C12—H12	0.9300
N1—C1	1.321 (8)	C13—C14	1.374 (8)
N2—C7	1.400 (8)	C13—H13	0.9300
N2—H2N	0.8600	C15—C16	1.352 (9)
N3—C8	1.298 (9)	C15—H15	0.9300
N3—N4	1.320 (8)	C16—C21	1.378 (8)
N4—C14	1.364 (8)	C16—C17	1.389 (10)
N4—H4N	0.8600	C17—C18	1.340 (13)
N5—C15	1.295 (10)	C17—H17	0.9300
N5—N6	1.312 (9)	C18—C19	1.347 (13)
N6—C21	1.409 (9)	C18—H18	0.9300
N6—H6N	0.8600	C19—C20	1.368 (13)
N7—C22	1.315 (10)	C19—H19	0.9300
N7—N8	1.347 (9)	C20—C21	1.397 (10)
N8—C28	1.359 (9)	C20—H20	0.9300
N8—H8N	0.8600	C22—C23	1.424 (10)
C1—C2	1.377 (8)	C22—H22	0.9300
C1—H1	0.9300	C23—C28	1.362 (11)
C2—C7	1.388 (9)	C23—C24	1.399 (12)
C2—C3	1.404 (9)	C24—C25	1.391 (13)
C3—C4	1.348 (11)	C24—H24	0.9300
C3—H3	0.9300	C25—C26	1.368 (14)
C4—C5	1.398 (12)	C25—H25	0.9300
C4—H4	0.9300	C26—C27	1.330 (13)
C5—C6	1.372 (11)	C26—H26	0.9300
C5—H5	0.9300	C27—C28	1.415 (11)
C6—C7	1.396 (9)	C27—H27	0.9300

N3—Cu1—N3ⁱ	180.0 (4)	C5—C6—C7	118.0 (8)
N3—Cu1—N1	88.2 (2)	C5—C6—H6	121.0
N3ⁱ—Cu1—N1	91.8 (2)	C7—C6—H6	121.0
N3—Cu1—N1ⁱ	91.8 (2)	C2—C7—C6	121.1 (6)
N3ⁱ—Cu1—N1ⁱ	88.2 (2)	C2—C7—N2	104.9 (6)
N1—Cu1—N1ⁱ	180.00 (16)	C6—C7—N2	133.9 (7)
N3—Cu1—Br1ⁱ	90.3 (2)	N3—C8—C9	111.5 (6)
N3ⁱ—Cu1—Br1ⁱ	89.7 (2)	N3—C8—H8	124.2
N1—Cu1—Br1ⁱ	89.84 (18)	C9—C8—H8	124.2
N1ⁱ—Cu1—Br1ⁱ	90.16 (18)	C8—C9—C10	134.8 (7)
N3—Cu1—Br1	89.7 (2)	C8—C9—C14	105.7 (6)
N3ⁱ—Cu1—Br1	90.3 (2)	C10—C9—C14	119.6 (6)
N1—Cu1—Br1	90.16 (18)	C11—C10—C9	119.0 (8)
N1ⁱ—Cu1—Br1	89.84 (18)	C11—C10—H10	120.5
Br1ⁱ—Cu1—Br1	180.00 (3)	C9—C10—H10	120.5
N7ⁱⁱ—Cu2—N7	180.000 (2)	C10—C11—C12	121.1 (7)
N7ⁱⁱ—Cu2—N5ⁱⁱ	91.3 (2)	C10—C11—H11	119.5
N7—Cu2—N5ⁱⁱ	88.7 (2)	C12—C11—H11	119.5
N7ⁱⁱ—Cu2—N5	88.7 (2)	C13—C12—C11	121.2 (7)
N7—Cu2—N5	91.3 (2)	C13—C12—H12	119.4
N5ⁱⁱ—Cu2—N5	180.000 (2)	C11—C12—H12	119.4
N7ⁱⁱ—Cu2—Br2	89.4 (2)	C12—C13—C14	118.6 (8)
N7—Cu2—Br2	90.6 (2)	C12—C13—H13	120.7
N5ⁱⁱ—Cu2—Br2	92.4 (3)	C14—C13—H13	120.7
N5—Cu2—Br2	87.6 (3)	N4—C14—C13	135.3 (7)
N7ⁱⁱ—Cu2—Br2ⁱⁱ	90.6 (2)	N4—C14—C9	104.2 (5)
N7—Cu2—Br2ⁱⁱ	89.4 (2)	C13—C14—C9	120.6 (6)
N5ⁱⁱ—Cu2—Br2ⁱⁱ	87.6 (3)	N5—C15—C16	112.9 (6)
N5—Cu2—Br2ⁱⁱ	92.4 (3)	N5—C15—H15	123.6
Br2—Cu2—Br2ⁱⁱ	180.00 (3)	C16—C15—H15	123.6
N2—N1—C1	107.6 (5)	C15—C16—C21	106.6 (6)
N2—N1—Cu1	127.4 (5)	C15—C16—C17	132.2 (7)
C1—N1—Cu1	125.0 (5)	C21—C16—C17	121.2 (7)
N1—N2—C7	110.5 (6)	C18—C17—C16	117.3 (8)
N1—N2—H2N	124.8	C18—C17—H17	121.3
C7—N2—H2N	124.8	C16—C17—H17	121.3
C8—N3—N4	106.6 (6)	C17—C18—C19	122.6 (9)
C8—N3—Cu1	129.2 (5)	C17—C18—H18	118.7
N4—N3—Cu1	124.0 (6)	C19—C18—H18	118.7
N3—N4—C14	112.1 (6)	C18—C19—C20	121.9 (8)
N3—N4—H4N	124.0	C18—C19—H19	119.1
C14—N4—H4N	124.0	C20—C19—H19	119.1
C15—N5—N6	105.9 (6)	C19—C20—C21	117.1 (7)
C15—N5—Cu2	127.4 (6)	C19—C20—H20	121.5
N6—N5—Cu2	126.4 (7)	C21—C20—H20	121.5
N5—N6—C21	111.7 (7)	C16—C21—C20	119.8 (6)
N5—N6—H6N	124.1	C16—C21—N6	102.9 (6)
C21—N6—H6N	124.1	C20—C21—N6	137.2 (7)
C22—N7—N8	108.1 (6)	N7—C22—C23	108.8 (8)
C22—N7—Cu2	131.1 (6)	N7—C22—H22	125.6
N8—N7—Cu2	120.6 (6)	C23—C22—H22	125.6
N7—N8—C28	110.0 (7)	C28—C23—C24	118.2 (8)
N7—N8—H8N	125.0	C28—C23—C22	105.7 (7)
C28—N8—H8N	125.0	C24—C23—C22	136.1 (10)
N1—C1—C2	110.9 (6)	C25—C24—C23	117.5 (10)
N1—C1—H1	124.6	C25—C24—H24	121.2
C2—C1—H1	124.6	C23—C24—H24	121.2
C1—C2—C7	106.1 (5)	C26—C25—C24	122.1 (9)
C1—C2—C3	134.0 (7)	C26—C25—H25	119.0
C7—C2—C3	119.9 (6)	C24—C25—H25	119.0
C4—C3—C2	118.4 (8)	C27—C26—C25	121.9 (10)
C4—C3—H3	120.8	C27—C26—H26	119.0
C2—C3—H3	120.8	C25—C26—H26	119.0
C3—C4—C5	122.1 (7)	C26—C27—C28	116.4 (10)
C3—C4—H4	119.0	C26—C27—H27	121.8
C5—C4—H4	119.0	C28—C27—H27	121.8
C6—C5—C4	120.4 (7)	N8—C28—C23	107.4 (7)
C6—C5—H5	119.8	N8—C28—C27	128.8 (9)
C4—C5—H5	119.8	C23—C28—C27	123.8 (8)

N3—Cu1—N1—N2	−93.9 (5)	C5—C6—C7—N2	179.1 (7)
N3ⁱ—Cu1—N1—N2	86.1 (5)	N1—N2—C7—C2	−0.1 (7)
Br1ⁱ—Cu1—N1—N2	−3.6 (5)	N1—N2—C7—C6	178.9 (7)
Br1—Cu1—N1—N2	176.4 (5)	N4—N3—C8—C9	−0.4 (8)
N3—Cu1—N1—C1	84.4 (5)	Cu1—N3—C8—C9	174.8 (4)
N3ⁱ—Cu1—N1—C1	−95.6 (5)	N3—C8—C9—C10	−178.6 (8)
Br1ⁱ—Cu1—N1—C1	174.6 (5)	N3—C8—C9—C14	0.5 (7)
Br1—Cu1—N1—C1	−5.4 (5)	C8—C9—C10—C11	178.9 (7)
C1—N1—N2—C7	−0.5 (7)	C14—C9—C10—C11	−0.2 (11)
Cu1—N1—N2—C7	178.0 (4)	C9—C10—C11—C12	0.4 (13)
N1—Cu1—N3—C8	−91.4 (6)	C10—C11—C12—C13	−0.7 (13)
N1ⁱ—Cu1—N3—C8	88.6 (6)	C11—C12—C13—C14	0.7 (12)
Br1ⁱ—Cu1—N3—C8	178.8 (6)	N3—N4—C14—C13	178.6 (7)
Br1—Cu1—N3—C8	−1.2 (6)	N3—N4—C14—C9	0.3 (7)
N1—Cu1—N3—N4	83.0 (5)	C12—C13—C14—N4	−178.6 (7)
N1ⁱ—Cu1—N3—N4	−97.0 (5)	C12—C13—C14—C9	−0.5 (10)
Br1ⁱ—Cu1—N3—N4	−6.8 (5)	C8—C9—C14—N4	−0.5 (7)
Br1—Cu1—N3—N4	173.2 (5)	C10—C9—C14—N4	178.9 (6)
C8—N3—N4—C14	0.1 (7)	C8—C9—C14—C13	−179.1 (6)
Cu1—N3—N4—C14	−175.4 (4)	C10—C9—C14—C13	0.2 (10)
N7ⁱⁱ—Cu2—N5—C15	91.4 (7)	N6—N5—C15—C16	−0.1 (8)
N7—Cu2—N5—C15	−88.6 (7)	Cu2—N5—C15—C16	−173.3 (4)
Br2—Cu2—N5—C15	2.0 (6)	N5—C15—C16—C21	−0.2 (8)
Br2ⁱⁱ—Cu2—N5—C15	−178.0 (6)	N5—C15—C16—C17	−179.4 (7)
N7ⁱⁱ—Cu2—N5—N6	−80.5 (6)	C15—C16—C17—C18	−179.4 (8)
N7—Cu2—N5—N6	99.5 (6)	C21—C16—C17—C18	1.5 (11)
Br2—Cu2—N5—N6	−170.0 (6)	C16—C17—C18—C19	−1.3 (14)
Br2ⁱⁱ—Cu2—N5—N6	10.0 (6)	C17—C18—C19—C20	−0.2 (15)
C15—N5—N6—C21	0.3 (8)	C18—C19—C20—C21	1.5 (13)
Cu2—N5—N6—C21	173.7 (4)	C15—C16—C21—C20	−179.5 (6)
N5ⁱⁱ—Cu2—N7—C22	−92.2 (7)	C17—C16—C21—C20	−0.2 (10)
N5—Cu2—N7—C22	87.8 (7)	C15—C16—C21—N6	0.4 (7)
Br2—Cu2—N7—C22	0.3 (7)	C17—C16—C21—N6	179.7 (6)
Br2ⁱⁱ—Cu2—N7—C22	−179.7 (7)	C19—C20—C21—C16	−1.3 (11)
N5ⁱⁱ—Cu2—N7—N8	83.4 (6)	C19—C20—C21—N6	178.9 (7)
N5—Cu2—N7—N8	−96.6 (6)	N5—N6—C21—C16	−0.4 (7)
Br2—Cu2—N7—N8	175.8 (5)	N5—N6—C21—C20	179.4 (8)
Br2ⁱⁱ—Cu2—N7—N8	−4.2 (5)	N8—N7—C22—C23	−0.7 (8)
C22—N7—N8—C28	0.8 (8)	Cu2—N7—C22—C23	175.2 (5)
Cu2—N7—N8—C28	−175.7 (5)	N7—C22—C23—C28	0.4 (8)
N2—N1—C1—C2	0.9 (7)	N7—C22—C23—C24	178.5 (8)
Cu1—N1—C1—C2	−177.6 (4)	C28—C23—C24—C25	−1.7 (11)
N1—C1—C2—C7	−1.0 (7)	C22—C23—C24—C25	−179.7 (8)
N1—C1—C2—C3	179.1 (7)	C23—C24—C25—C26	0.6 (14)
C1—C2—C3—C4	−179.0 (7)	C24—C25—C26—C27	0.0 (15)
C7—C2—C3—C4	1.1 (11)	C25—C26—C27—C28	0.5 (14)
C2—C3—C4—C5	−3.0 (12)	N7—N8—C28—C23	−0.5 (8)
C3—C4—C5—C6	2.4 (12)	N7—N8—C28—C27	178.6 (7)
C4—C5—C6—C7	0.2 (11)	C24—C23—C28—N8	−178.4 (7)
C1—C2—C7—C6	−178.5 (6)	C22—C23—C28—N8	0.1 (8)
C3—C2—C7—C6	1.4 (10)	C24—C23—C28—C27	2.4 (11)
C1—C2—C7—N2	0.6 (7)	C22—C23—C28—C27	−179.1 (7)
C3—C2—C7—N2	−179.4 (6)	C26—C27—C28—N8	179.2 (8)
C5—C6—C7—C2	−2.0 (10)	C26—C27—C28—C23	−1.7 (13)

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

Experimental details

Crystal data
Chemical formula	[CuBr₂(C₇H₆N₂)₄]
M_r	695.91
Crystal system, space group	Triclinic, P1
Temperature (K)	295
a, b, c (Å)	10.338 (1), 10.923 (1), 13.730 (1)
α, β, γ (°)	72.545 (3), 77.329 (3), 73.890 (3)
V (Å³)	1405.3 (3)
Z	2
Radiation type	Mo Kα
µ (mm⁻¹)	3.65
Crystal size (mm)	0.24 × 0.21 × 0.12

Data collection
Diffractometer	Rigaku R-AXIS RAPID
Absorption correction	Multi-scan (ABSCOR; Higashi, 1995)
T_min, T_max	0.073, 0.668
No. of measured, independent and observed [I > 2σ(I)] reflections	13779, 6389, 2895
R_int	0.046
(sin θ/λ)_max (Å⁻¹)	0.650

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.061, 0.228, 1.13
No. of reflections	6389
No. of parameters	356
No. of restraints	12
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.65, −1.00

Computer programs: RAPID-AUTO (Rigaku Corporation, 1998), CrystalStructure (Rigaku/MSC, 2002), SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), X-SEED (Barbour, 2001), publCIF (Westrip, 2007).

Selected bond lengths (Å) top

Cu1—N1	2.027 (5)	Cu2—N5	2.024 (7)
Cu1—N3	2.008 (6)	Cu2—N7	2.023 (6)
Cu1—Br1	3.033 (1)	Cu2—Br2	2.980 (1)

Acknowledgements

The authors thank the Research Office of Azarbaijan University of Tarbiat Moallem, Heilongjiang Province Natural Science Foundation (grant No. B200501), the Scientific Fund for Remarkable Teachers of Heilongjiang Province (grant No. 1054G036), Heilongjiang University and the University of Malaya for supporting this work.

References

Allen, F. H. (2002). Acta Cryst. B58, 380–388. Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
Barbour, L. J. (2001). J. Supramol. Chem. 1, 189–191. CrossRef CAS Google Scholar
Higashi, T. (1995). ABSCOR. Rigaku Corporation, Tokyo, Japan. Google Scholar
Hossaini Sadr, M., Jalili, A. R., Razmi, H. & Ng, S. W. (2005). J. Organomet. Chem. 690, 2128–2132. Web of Science CSD CrossRef Google Scholar
Hossaini Sadr, M., Sardroodi, J. J., Zare, D., Brooks, N. R., Clegg, W. & Song, Y. (2006). Polyhedron, 25, 3285–3288. Web of Science CSD CrossRef CAS Google Scholar
Hossaini Sadr, M., Zare, D., Lewis, W., Wikaira, J., Robinson, W. T. & Ng, S. W. (2004). Acta Cryst. E60, m1324–m1326. Web of Science CSD CrossRef IUCr Journals Google Scholar
Rigaku Corporation (1998). RAPID-AUTO. Rigaku Corporation, Tokyo, Japan. Google Scholar
Rigaku/MSC (2002). CrystalStructure. Rigaku/MSC, The Woodlands, Texas, USA. Google Scholar
Sheldrick, G. M. (1997). SHELXL97 and SHELXS97. University of Göttingen, Germany. Google Scholar
Westrip, S. P. (2007). publCIF. In preparation. Google Scholar