Bis(μ-nitrito-κ(2)O:O)bis-[bis-(1-methyl-1H-imidazole-κN(3))(nitrito-κO)copper(II)].

In the binuclear title compound, [Cu(2)(NO(2))(4)(C(4)H(6)N(2))(4)], centro-symmetric-ally related complex mol-ecules are linked via weak Cu-O inter-actions, forming dimeric units. The Cu(II) atom displays an elongated square-pyramidal CuN(2)O(3) coordination geometry with a slight tetra-hedral distortion of the basal plane [maximum deviation = 0.249 (2) Å]. The dihedral angle formed by the imidazole rings is 26.20 (10)°.

Related literature

The structure of the title compound was determined as part of our ongoing study of potential ferroelectric phase change materials. For general background to ferroelectric compounds with metal-organic framework structures, see: Fu et al. (2009 ▶); Ye et al. (2006 ▶); Zhang et al. (2008 ▶, 2010 ▶). For a related structure, see: Costes et al. (1995 ▶).

Experimental

Crystal data

[Cu2(NO2)4(C4H6N2)4]

M = 639.55

Triclinic,

a = 7.8281 (16) Å

b = 8.4873 (17) Å

c = 10.054 (2) Å

α = 80.35 (3)°

β = 77.72 (3)°

γ = 79.46 (3)°

V = 635.9 (2) Å3

Z = 1

Mo Kα radiation

μ = 1.74 mm−1

T = 293 K

0.29 × 0.23 × 0.20 mm

Data collection

Rigaku SCXmini diffractometer

Absorption correction: multi-scan (CrystalClear; Rigaku, 2005 ▶) T min = 0.625, T max = 0.706

6578 measured reflections

2900 independent reflections

2465 reflections with I > 2σ(I)

R int = 0.035

Refinement

R[F 2 > 2σ(F 2)] = 0.037

wR(F 2) = 0.091

S = 1.05

2900 reflections

174 parameters

H-atom parameters constrained

Δρmax = 0.40 e Å−3

Δρmin = −0.29 e Å−3

Data collection: CrystalClear (Rigaku, 2005 ▶); cell refinement: CrystalClear; data reduction: CrystalClear; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: DIAMOND (Brandenburg & Putz, 2005 ▶); software used to prepare material for publication: SHELXL97.

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536812009804/rz2715sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812009804/rz2715Isup2.hkl

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

[Cu2(NO2)4(C4H6N2)4]	Z = 1
Mr = 639.55	F(000) = 326
Triclinic, P1	Dx = 1.670 Mg m−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 7.8281 (16) Å	Cell parameters from 2900 reflections
b = 8.4873 (17) Å	θ = 2.3–27.5°
c = 10.054 (2) Å	µ = 1.74 mm−1
α = 80.35 (3)°	T = 293 K
β = 77.72 (3)°	Prism, blue
γ = 79.46 (3)°	0.29 × 0.23 × 0.20 mm
V = 635.9 (2) Å3

Rigaku SCXmini diffractometer	2465 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.035
Graphite monochromator	θmax = 27.5°, θmin = 3.0°
ω scans	h = −10→10
Absorption correction: multi-scan (CrystalClear; Rigaku, 2005)	k = −11→11
Tmin = 0.625, Tmax = 0.706	l = −13→13
6578 measured reflections	2 standard reflections every 150 reflections
2900 independent reflections	intensity decay: none

Refinement on F2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.037	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.091	H-atom parameters constrained
S = 1.05	w = 1/[σ2(Fo2) + (0.0423P)2 + 0.1143P] where P = (Fo2 + 2Fc2)/3
2900 reflections	(Δ/σ)max = 0.001
174 parameters	Δρmax = 0.40 e Å−3
0 restraints	Δρmin = −0.29 e Å−3

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
C1	0.7413 (4)	0.2449 (4)	0.4825 (3)	0.0549 (8)
H1A	0.7735	0.1313	0.4761	0.082*
H1B	0.7220	0.2619	0.5769	0.082*
H1C	0.8349	0.3012	0.4302	0.082*
C2	0.5675 (3)	0.4011 (3)	0.3090 (3)	0.0365 (6)
H2	0.6629	0.4389	0.2480	0.044*
C3	0.3061 (4)	0.3554 (4)	0.4028 (3)	0.0496 (8)
H3	0.1847	0.3553	0.4178	0.059*
C4	0.4134 (4)	0.2788 (4)	0.4889 (3)	0.0520 (8)
H4	0.3803	0.2185	0.5738	0.062*
C5	−0.1244 (4)	0.9207 (4)	−0.2032 (3)	0.0490 (8)
H5A	−0.2148	0.8597	−0.1523	0.074*
H5B	−0.0952	0.8978	−0.2964	0.074*
H5C	−0.1667	1.0341	−0.2020	0.074*
C6	0.0619 (3)	0.7480 (3)	−0.0451 (3)	0.0341 (6)
H6	−0.0165	0.6746	−0.0090	0.041*
C7	0.2892 (4)	0.8716 (3)	−0.0865 (3)	0.0384 (6)
H7	0.3984	0.8980	−0.0837	0.046*
C8	0.1763 (4)	0.9545 (3)	−0.1664 (3)	0.0411 (6)
H8	0.1925	1.0480	−0.2277	0.049*
N1	0.6145 (3)	0.7315 (3)	0.0924 (3)	0.0485 (6)
N3	0.5793 (3)	0.3061 (3)	0.4283 (2)	0.0376 (5)
N2	−0.0346 (3)	0.5775 (3)	0.2749 (3)	0.0495 (7)
N4	0.4024 (3)	0.4338 (3)	0.2893 (2)	0.0334 (5)
N5	0.2167 (3)	0.7405 (2)	−0.0090 (2)	0.0314 (5)
N6	0.0336 (3)	0.8755 (3)	−0.1406 (2)	0.0355 (5)
O1	0.5052 (3)	0.7955 (3)	0.1808 (2)	0.0541 (5)
O2	0.5618 (2)	0.6202 (2)	0.04605 (19)	0.0402 (4)
O3	0.0807 (3)	0.4952 (2)	0.1912 (2)	0.0422 (5)
O4	0.0182 (3)	0.6897 (3)	0.3082 (2)	0.0542 (6)
Cu1	0.31394 (4)	0.57713 (4)	0.13253 (3)	0.02903 (12)

	U11	U22	U33	U12	U13	U23
C1	0.0475 (18)	0.067 (2)	0.0476 (18)	0.0037 (15)	−0.0230 (15)	0.0039 (16)
C2	0.0324 (13)	0.0429 (16)	0.0316 (14)	−0.0020 (11)	−0.0056 (11)	−0.0021 (11)
C3	0.0389 (15)	0.063 (2)	0.0424 (17)	−0.0159 (14)	−0.0080 (13)	0.0158 (14)
C4	0.0492 (18)	0.066 (2)	0.0363 (16)	−0.0152 (15)	−0.0087 (14)	0.0143 (14)
C5	0.0434 (16)	0.0549 (19)	0.0458 (17)	0.0069 (14)	−0.0183 (14)	−0.0016 (14)
C6	0.0320 (13)	0.0338 (14)	0.0361 (14)	−0.0022 (10)	−0.0103 (11)	−0.0019 (11)
C7	0.0386 (14)	0.0354 (15)	0.0410 (15)	−0.0103 (11)	−0.0087 (12)	0.0016 (12)
C8	0.0473 (16)	0.0341 (15)	0.0391 (15)	−0.0068 (12)	−0.0096 (13)	0.0051 (12)
N1	0.0425 (14)	0.0497 (16)	0.0550 (16)	−0.0166 (12)	−0.0174 (12)	0.0094 (13)
N3	0.0383 (12)	0.0435 (13)	0.0294 (11)	−0.0013 (10)	−0.0103 (10)	−0.0004 (9)
N2	0.0326 (13)	0.0622 (18)	0.0475 (15)	−0.0074 (12)	−0.0065 (11)	0.0092 (13)
N4	0.0328 (11)	0.0378 (12)	0.0275 (11)	−0.0043 (9)	−0.0053 (9)	−0.0007 (9)
N5	0.0299 (11)	0.0318 (11)	0.0313 (11)	−0.0036 (9)	−0.0056 (9)	−0.0023 (9)
N6	0.0368 (12)	0.0352 (12)	0.0324 (11)	0.0020 (9)	−0.0093 (9)	−0.0032 (9)
O1	0.0652 (14)	0.0489 (13)	0.0529 (13)	−0.0133 (11)	−0.0137 (11)	−0.0116 (10)
O2	0.0361 (10)	0.0439 (11)	0.0383 (10)	−0.0065 (8)	−0.0062 (8)	0.0008 (8)
O3	0.0395 (10)	0.0432 (11)	0.0450 (11)	−0.0135 (9)	−0.0125 (9)	0.0041 (9)
O4	0.0547 (13)	0.0539 (14)	0.0501 (13)	−0.0016 (11)	−0.0062 (10)	−0.0076 (11)
Cu1	0.02605 (17)	0.03196 (19)	0.02820 (18)	−0.00537 (12)	−0.00609 (12)	0.00075 (12)

C1—N3	1.460 (4)	C6—N5	1.325 (3)
C1—H1A	0.9600	C6—N6	1.341 (3)
C1—H1B	0.9600	C6—H6	0.9300
C1—H1C	0.9600	C7—C8	1.344 (4)
C2—N4	1.321 (3)	C7—N5	1.385 (3)
C2—N3	1.339 (3)	C7—H7	0.9300
C2—H2	0.9300	C8—N6	1.363 (3)
C3—C4	1.341 (4)	C8—H8	0.9300
C3—N4	1.370 (3)	N1—O1	1.219 (3)
C3—H3	0.9300	N1—O2	1.286 (3)
C4—N3	1.356 (4)	N2—O4	1.225 (3)
C4—H4	0.9300	N2—O3	1.286 (3)
C5—N6	1.466 (3)	N4—Cu1	1.989 (2)
C5—H5A	0.9600	N5—Cu1	1.985 (2)
C5—H5B	0.9600	O2—Cu1	2.0221 (19)
C5—H5C	0.9600	O3—Cu1	2.0085 (19)
N3—C1—H1A	109.5	N5—C7—H7	125.5
N3—C1—H1B	109.5	C7—C8—N6	107.0 (2)
H1A—C1—H1B	109.5	C7—C8—H8	126.5
N3—C1—H1C	109.5	N6—C8—H8	126.5
H1A—C1—H1C	109.5	O1—N1—O2	114.3 (2)
H1B—C1—H1C	109.5	C2—N3—C4	107.2 (2)
N4—C2—N3	111.1 (2)	C2—N3—C1	126.1 (2)
N4—C2—H2	124.4	C4—N3—C1	126.8 (2)
N3—C2—H2	124.4	O4—N2—O3	114.5 (2)
C4—C3—N4	109.7 (3)	C2—N4—C3	105.2 (2)
C4—C3—H3	125.2	C2—N4—Cu1	126.73 (18)
N4—C3—H3	125.2	C3—N4—Cu1	127.94 (19)
C3—C4—N3	106.8 (2)	C6—N5—C7	105.6 (2)
C3—C4—H4	126.6	C6—N5—Cu1	125.75 (18)
N3—C4—H4	126.6	C7—N5—Cu1	128.63 (18)
N6—C5—H5A	109.5	C6—N6—C8	107.5 (2)
N6—C5—H5B	109.5	C6—N6—C5	125.5 (2)
H5A—C5—H5B	109.5	C8—N6—C5	127.0 (2)
N6—C5—H5C	109.5	N1—O2—Cu1	115.28 (17)
H5A—C5—H5C	109.5	N2—O3—Cu1	114.51 (17)
H5B—C5—H5C	109.5	N5—Cu1—N4	173.10 (8)
N5—C6—N6	110.9 (2)	N5—Cu1—O3	90.30 (8)
N5—C6—H6	124.6	N4—Cu1—O3	89.99 (9)
N6—C6—H6	124.6	N5—Cu1—O2	90.40 (8)
C8—C7—N5	109.1 (2)	N4—Cu1—O2	90.85 (8)
C8—C7—H7	125.5	O3—Cu1—O2	167.15 (8)
N4—C3—C4—N3	−1.2 (4)	C7—C8—N6—C5	179.9 (3)
N5—C7—C8—N6	−0.5 (3)	O1—N1—O2—Cu1	−0.8 (3)
N4—C2—N3—C4	−0.9 (3)	O4—N2—O3—Cu1	−1.9 (3)
N4—C2—N3—C1	179.4 (3)	C6—N5—Cu1—O3	−9.1 (2)
C3—C4—N3—C2	1.3 (3)	C7—N5—Cu1—O3	168.4 (2)
C3—C4—N3—C1	−179.0 (3)	C6—N5—Cu1—O2	158.1 (2)
N3—C2—N4—C3	0.2 (3)	C7—N5—Cu1—O2	−24.4 (2)
N3—C2—N4—Cu1	177.04 (17)	C2—N4—Cu1—O3	168.7 (2)
C4—C3—N4—C2	0.7 (4)	C3—N4—Cu1—O3	−15.1 (3)
C4—C3—N4—Cu1	−176.2 (2)	C2—N4—Cu1—O2	1.6 (2)
N6—C6—N5—C7	0.1 (3)	C3—N4—Cu1—O2	177.7 (2)
N6—C6—N5—Cu1	178.14 (16)	N2—O3—Cu1—N5	−82.48 (18)
C8—C7—N5—C6	0.3 (3)	N2—O3—Cu1—N4	90.62 (18)
C8—C7—N5—Cu1	−177.67 (19)	N2—O3—Cu1—O2	−175.6 (3)
N5—C6—N6—C8	−0.5 (3)	N1—O2—Cu1—N5	90.08 (18)
N5—C6—N6—C5	−179.8 (2)	N1—O2—Cu1—N4	−83.13 (18)
C7—C8—N6—C6	0.6 (3)	N1—O2—Cu1—O3	−176.8 (3)