catena-Poly[[bis-(1-ethyl-1H-imidazole-κN)copper(II)]-μ-oxalato-κO,O:O,O].

The title compound, [Cu(C(2)O(4))(C(5)H(8)N(2))(2)](n), is composed of one-dimensional linear chains running parallel to the a axis. In the chain, trans-[Cu(imidazole)(2)](2+) units are sequentially bridged by bis-bidentate oxalate ligands, resulting in an octa-hedral CuO(4)N(2) donor set. The Cu⋯Cu separation through the oxalate bridge is 5.620 (5) Å. Both the Cu atoms and the C-C bond of the oxalate bridge are bis-ected by inversion centres.

Related literature

For general background on ferroelectric organic compounds with framework structures, see: Fu et al. (2009 ▶); Ye et al. (2006 ▶); Zhang et al. (2008 ▶, 2010 ▶).

Experimental

Crystal data

[Cu(C2O4)(C5H8N2)2]

M = 343.83

Monoclinic,

a = 5.6200 (11) Å

b = 8.8577 (18) Å

c = 14.481 (3) Å

β = 96.55 (3)°

V = 716.2 (2) Å3

Z = 2

Mo Kα radiation

μ = 1.55 mm−1

T = 293 K

0.30 × 0.25 × 0.20 mm

Data collection

Rigaku SCXmini diffractometer

Absorption correction: multi-scan (CrystalClear; Rigaku, 2005 ▶) T min = 0.635, T max = 0.734

7300 measured reflections

1653 independent reflections

1267 reflections with I > 2σ(I)

R int = 0.062

Refinement

R[F 2 > 2σ(F 2)] = 0.040

wR(F 2) = 0.092

S = 1.05

1653 reflections

98 parameters

H-atom parameters constrained

Δρmax = 0.48 e Å−3

Δρmin = −0.33 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: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXL97.

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536811043121/bg2425sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811043121/bg2425Isup2.hkl

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

[Cu(C2O4)(C5H8N2)2]	F(000) = 354
Mr = 343.83	Dx = 1.594 Mg m−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 1653 reflections
a = 5.6200 (11) Å	θ = 2.3–27.5°
b = 8.8577 (18) Å	µ = 1.55 mm−1
c = 14.481 (3) Å	T = 293 K
β = 96.55 (3)°	Block, blue
V = 716.2 (2) Å3	0.30 × 0.25 × 0.20 mm
Z = 2

Rigaku SCXmini diffractometer	1267 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.062
graphite	θmax = 27.5°, θmin = 3.7°
ω scans	h = −7→7
Absorption correction: multi-scan (CrystalClear; Rigaku, 2005)	k = −11→11
Tmin = 0.635, Tmax = 0.734	l = −18→18
7300 measured reflections	2 standard reflections every 150 reflections
1653 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)] = 0.040	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.092	H-atom parameters constrained
S = 1.05	w = 1/[σ2(Fo2) + (0.0361P)2 + 0.3394P] where P = (Fo2 + 2Fc2)/3
1653 reflections	(Δ/σ)max < 0.001
98 parameters	Δρmax = 0.48 e Å−3
0 restraints	Δρmin = −0.33 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
Cu1	0.0000	0.5000	0.5000	0.02341 (16)
C1	0.0677 (5)	0.4366 (4)	0.3025 (2)	0.0326 (7)
H1	0.1452	0.3463	0.3194	0.039*
C2	−0.1151 (5)	0.6469 (4)	0.3090 (2)	0.0365 (7)
H2	−0.1900	0.7304	0.3318	0.044*
C3	−0.0853 (6)	0.6229 (4)	0.2184 (2)	0.0397 (8)
H3	−0.1337	0.6861	0.1685	0.048*
C4	0.1083 (6)	0.4132 (4)	0.1331 (2)	0.0439 (8)
H4A	−0.0227	0.4136	0.0833	0.053*
H4B	0.1477	0.3088	0.1482	0.053*
C5	0.3213 (7)	0.4885 (4)	0.0999 (3)	0.0534 (9)
H5A	0.2801	0.5899	0.0809	0.080*
H5B	0.3701	0.4333	0.0482	0.080*
H5C	0.4505	0.4906	0.1494	0.080*
C6	0.4839 (4)	0.4123 (3)	0.49195 (17)	0.0210 (5)
N1	−0.0177 (4)	0.5292 (3)	0.36168 (15)	0.0282 (6)
N2	0.0296 (4)	0.4876 (3)	0.21516 (16)	0.0339 (6)
O1	0.3372 (3)	0.6619 (2)	0.52150 (13)	0.0291 (5)
O2	0.2754 (3)	0.3599 (2)	0.49398 (12)	0.0259 (4)

	U11	U22	U33	U12	U13	U23
Cu1	0.0188 (2)	0.0301 (3)	0.0218 (2)	0.0016 (2)	0.00409 (16)	−0.0002 (2)
C1	0.0357 (16)	0.0345 (16)	0.0279 (16)	0.0039 (14)	0.0056 (13)	0.0016 (13)
C2	0.0367 (16)	0.0403 (18)	0.0333 (16)	0.0065 (14)	0.0067 (13)	0.0027 (14)
C3	0.0414 (17)	0.0478 (19)	0.0291 (16)	0.0012 (16)	0.0010 (13)	0.0095 (15)
C4	0.050 (2)	0.056 (2)	0.0266 (16)	−0.0079 (17)	0.0082 (14)	−0.0087 (15)
C5	0.063 (2)	0.050 (2)	0.052 (2)	−0.0054 (19)	0.0277 (19)	0.0000 (18)
C6	0.0211 (12)	0.0244 (14)	0.0172 (12)	0.0034 (12)	0.0008 (10)	0.0010 (11)
N1	0.0265 (12)	0.0336 (15)	0.0248 (12)	0.0027 (10)	0.0048 (10)	0.0015 (10)
N2	0.0358 (13)	0.0422 (15)	0.0238 (12)	−0.0023 (12)	0.0042 (10)	−0.0010 (11)
O1	0.0235 (9)	0.0270 (11)	0.0374 (11)	0.0020 (8)	0.0069 (8)	−0.0030 (9)
O2	0.0197 (9)	0.0269 (10)	0.0316 (10)	−0.0014 (8)	0.0054 (8)	−0.0003 (9)

Cu1—O2	1.9935 (18)	C3—H3	0.9300
Cu1—O2i	1.9935 (18)	C4—N2	1.470 (4)
Cu1—N1	2.011 (2)	C4—C5	1.497 (4)
Cu1—N1i	2.011 (2)	C4—H4A	0.9700
Cu1—O1i	2.3684 (18)	C4—H4B	0.9700
Cu1—O1	2.3684 (19)	C5—H5A	0.9600
C1—N1	1.316 (4)	C5—H5B	0.9600
C1—N2	1.337 (4)	C5—H5C	0.9600
C1—H1	0.9300	C6—O1ii	1.235 (3)
C2—C3	1.359 (4)	C6—O2	1.264 (3)
C2—N1	1.368 (4)	C6—C6ii	1.579 (5)
C2—H2	0.9300	O1—C6ii	1.235 (3)
C3—N2	1.365 (4)
O2—Cu1—O2i	180.000 (1)	N2—C4—C5	112.7 (3)
O2—Cu1—N1	89.27 (8)	N2—C4—H4A	109.1
O2i—Cu1—N1	90.73 (8)	C5—C4—H4A	109.1
O2—Cu1—N1i	90.73 (8)	N2—C4—H4B	109.1
O2i—Cu1—N1i	89.27 (8)	C5—C4—H4B	109.1
N1—Cu1—N1i	180.000 (1)	H4A—C4—H4B	107.8
O2—Cu1—O1i	103.35 (7)	C4—C5—H5A	109.5
O2i—Cu1—O1i	76.65 (7)	C4—C5—H5B	109.5
N1—Cu1—O1i	89.94 (8)	H5A—C5—H5B	109.5
N1i—Cu1—O1i	90.06 (8)	C4—C5—H5C	109.5
O2—Cu1—O1	76.65 (7)	H5A—C5—H5C	109.5
O2i—Cu1—O1	103.35 (7)	H5B—C5—H5C	109.5
N1—Cu1—O1	90.06 (8)	O1ii—C6—O2	125.6 (2)
N1i—Cu1—O1	89.94 (8)	O1ii—C6—C6ii	117.7 (3)
O1i—Cu1—O1	180.00 (7)	O2—C6—C6ii	116.7 (3)
N1—C1—N2	112.0 (3)	C1—N1—C2	105.3 (2)
N1—C1—H1	124.0	C1—N1—Cu1	126.0 (2)
N2—C1—H1	124.0	C2—N1—Cu1	128.6 (2)
C3—C2—N1	109.5 (3)	C1—N2—C3	106.8 (2)
C3—C2—H2	125.2	C1—N2—C4	125.6 (3)
N1—C2—H2	125.2	C3—N2—C4	127.5 (3)
C2—C3—N2	106.3 (3)	C6ii—O1—Cu1	108.12 (16)
C2—C3—H3	126.8	C6—O2—Cu1	119.93 (16)
N2—C3—H3	126.8