catena-Poly[[(2,2′-bipyridine-κ2N,N′)nickel(II)]-μ-oxalato-κ4O1,O2:O1′,O2′]

Li, S.; Yan, X.-L.; Wang, S.-B.; Ma, Y.-F.

doi:10.1107/S1600536808028389

metal-organic compounds

CRYSTALLOGRAPHIC
COMMUNICATIONS

ISSN: 2056-9890

Volume 64| Part 10| October 2008| Page m1258

doi:10.1107/S1600536808028389

Open

access

RETRACTED ARTICLE

This article has been retracted. To view the retraction notice, click here.

Retracted: catena-Poly[[(2,2′-bipyridine-κ²N,N′)nickel(II)]-μ-oxalato-κ⁴O¹,O²:O^1′,O^2′]

Sheng Li,^a Xing-Lian Yan,^b Shou-Bin Wang ^c and Yuan-Fang Ma ^a ^*

^aInstitute of Immunology, Key Laboratory of Natural Drugs and Immunological Engineering of Henan Province, College of Medicine, Henan University, Kaifeng 475003, People's Republic of China, ^bFirst Affiliated Hospital, Henan University, Kaifeng 475003, People's Republic of China, and ^cCollege of Chemistry and Chemical Engineering, Henan University, Kaifeng 475003, People's Republic of China
^*Correspondence e-mail: mayf_hd@126.com

(Received 4 August 2008; accepted 4 September 2008; online 13 September 2008)

The title compound, [Ni(C₂O₄)(C₁₀H₈N₂)]_n, is isostructural with its Mn^II, Fe^II, Cu^II and Zn^II analogues. Each Ni^II atom is chelated by two oxalate ligands and one 2,2′-bipyridine, forming a slightly distorted octahedral geometry. Oxlate acts as a bridge to link neighbouring pairs of Ni^II cations, forming a one-dimensional wave-like chain. The crystal showed partial inversion twinning.

Related literature

For related literature, see: Hong & Do (1997 ); Eddaoudi et al. (2001 ); Liang et al. (2004 ); Shi et al. (2005 ). For the isostructural Mn^II, Fe^II, Cu^II and Zn^II complexes, see: Li et al. (2006 ); Deguenon et al. (1990 ); Fun et al. (1999 ); Luo et al. (2001 ); Yu et al. (2006 ); Lin et al. (2006 ).

Experimental

Crystal data

[Ni(C₂O₄)(C₁₀H₈N₂)]
M_r = 302.91
Orthorhombic, P n a 2₁
a = 9.6486 (14) Å
b = 9.2627 (14) Å
c = 13.883 (2) Å
V = 1240.7 (3) Å³
Z = 4
Mo Kα radiation
μ = 1.57 mm⁻¹
T = 296 (2) K
0.12 × 0.10 × 0.06 mm

Data collection

Bruker APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2001 ) T_min = 0.834, T_max = 0.912
6146 measured reflections
2114 independent reflections
1810 reflections with I > 2σ(I)
R_int = 0.030

Refinement

R[F² > 2σ(F²)] = 0.047
wR(F²) = 0.154
S = 1.00
2114 reflections
173 parameters
1 restraint
H-atom parameters constrained
Δρ_max = 0.44 e Å⁻³
Δρ_min = −0.43 e Å⁻³
Absolute structure: Flack (1983 ), 971 Friedel pairs
Flack parameter: 0.20 (3)

Data collection: APEX2 (Bruker, 2004 ); cell refinement: SAINT-Plus (Bruker, 2001); data reduction: SAINT-Plus; 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: SHELXTL.

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536808028389/cf2213sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536808028389/cf2213Isup2.hkl

checkCIF report

Comment top

The design of coordination compounds has attracted long-lasting research interest not only because of their appealing structural and topological novelty but also due to their unusual optical, electronic, magnetic and catalytic properties, and their further potential medical value derived from their antiviral properties and the inhibition of angiogenesis. To date, much of the work has been focused on coordination polymers with organic acid ligands (Hong et al. 1997; Eddaoudi et al. 2001; Liang et al. 2004; Shi et al.2005).

Here we report the synthesis and X-ray crystal structure analysis of the title compound, (I), with a bridging oxalate ligand. It is isostructural with its Mn^II, Fe^II, Cu^II, and Zn^II analogues (Li et al., 2006; Deguenon et al., 1990; Fun et al., 1999; Luo et al., 2001; Yu et al., 2006; Lin et al., 2006).

As shown in Fig. 1, the Ni(II) atom is chelated by two oxlates and one 2,2'-bipyridine, forming a slightly distorted octahedral geometry. Oxalate acts as a bridge to link neighboring pairs of Ni(II) cations, forming a one-dimensional wave-like chain (Fig. 2). The Ni—N and Ni—O bond lengths are in the ranges 2.239 (5)–2.243 (5) and 2.161 (4)–2.166 (4) Å, respectively.

Related literature top

For related literature, see: Hong & Do (1997); Eddaoudi et al. (2001); Liang et al. (2004); Shi et al. (2005). For the isostructural Mn^II, Fe^II, Cu^II and Zn^II complexes, see: Li et al. (2006); Deguenon et al. (1990); Fun et al. (1999); Luo et al. (2001); Yu et al. (2006); Lin et al. (2006).

Experimental top

A mixture of nickel(II) nitrate hexahydrate (0.1 mmol), oxalic acid (0.2 mmol), 2,2'-bipyridine (0.1 mmol), and water (16 ml) in a 25 ml Teflon-lined stainless steel autoclave was kept at 473 K for three days. Green crystals were obtained after cooling to room temperature, with a yield of 6%. Anal. Calc. for C₁₂H₈N₂NiO₄: C 47.54, H 2.64, N 9.24%; Found: C 47.51, H 2.58, N 9.16%.

Computing details top

Data collection: APEX2 (Bruker, 2004); cell refinement: SAINT-Plus (Bruker, 2001); data reduction: SAINT-Plus (Bruker, 2001); 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: SHELXTL (Sheldrick, 2008).

Figures top

	Fig. 1. The coordination of the Ni atom in the title structure, drawn with 30% probability displacement ellipsoids. [Symmetry code: (I) 1/2+x, 1/2-y, z.]
	Fig. 2. The chain of the title compound, viewed along the [010] direction.

catena-Poly[[(2,2'-bipyridine-κ²N,N')nickel(II)]- µ-oxalato-κ⁴O¹,O²:O^1',O^2'] top

Crystal data top

[Ni(C₂O₄)(C₁₀H₈N₂)]	F(000) = 616
M_r = 302.91	D_x = 1.622 Mg m⁻³
Orthorhombic, Pna2₁	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2c -2n	Cell parameters from 1779 reflections
a = 9.6486 (14) Å	θ = 2.6–21.5°
b = 9.2627 (14) Å	µ = 1.57 mm⁻¹
c = 13.883 (2) Å	T = 296 K
V = 1240.7 (3) Å³	Block, green
Z = 4	0.12 × 0.10 × 0.06 mm

Data collection top

Bruker APEXII CCD area-detector diffractometer	2114 independent reflections
Radiation source: fine-focus sealed tube	1810 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.030
ϕ and ω scans	θ_max = 25.1°, θ_min = 2.6°
Absorption correction: multi-scan (SADABS; Bruker, 2001)	h = −11→5
T_min = 0.834, T_max = 0.912	k = −11→11
6146 measured reflections	l = −16→16

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)] = 0.047	H-atom parameters constrained
wR(F²) = 0.154	w = 1/[σ²(F_o²) + (0.118P)²] where P = (F_o² + 2F_c²)/3
S = 1.00	(Δ/σ)_max < 0.001
2114 reflections	Δρ_max = 0.44 e Å⁻³
173 parameters	Δρ_min = −0.44 e Å⁻³
1 restraint	Absolute structure: Flack (1983), 971 Friedel pairs
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: 0.20 (3)

Crystal data top

[Ni(C₂O₄)(C₁₀H₈N₂)]	V = 1240.7 (3) Å³
M_r = 302.91	Z = 4
Orthorhombic, Pna2₁	Mo Kα radiation
a = 9.6486 (14) Å	µ = 1.57 mm⁻¹
b = 9.2627 (14) Å	T = 296 K
c = 13.883 (2) Å	0.12 × 0.10 × 0.06 mm

Data collection top

Bruker APEXII CCD area-detector diffractometer	2114 independent reflections
Absorption correction: multi-scan (SADABS; Bruker, 2001)	1810 reflections with I > 2σ(I)
T_min = 0.834, T_max = 0.912	R_int = 0.030
6146 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.047	H-atom parameters constrained
wR(F²) = 0.154	Δρ_max = 0.44 e Å⁻³
S = 1.00	Δρ_min = −0.44 e Å⁻³
2114 reflections	Absolute structure: Flack (1983), 971 Friedel pairs
173 parameters	Absolute structure parameter: 0.20 (3)
1 restraint

Special details top

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 (Å²) top

	x	y	z	U_iso*/U_eq
Ni1	0.88396 (7)	1.09402 (7)	0.25107 (8)	0.04352 (14)
O1	1.0093 (4)	1.2363 (5)	0.1613 (3)	0.0503 (11)
O2	1.0673 (4)	1.1297 (4)	0.3368 (3)	0.0415 (9)
O3	0.7686 (4)	1.2511 (5)	0.3347 (3)	0.0452 (10)
O4	0.7033 (4)	1.1389 (4)	0.1640 (3)	0.0416 (9)
N1	0.8006 (5)	0.9059 (5)	0.3352 (4)	0.0401 (11)
N2	0.9510 (5)	0.8925 (5)	0.1747 (4)	0.0395 (11)
C1	1.1555 (6)	1.2124 (6)	0.3004 (4)	0.0380 (12)
C2	1.1199 (4)	1.2745 (6)	0.1993 (4)	0.0305 (12)
C3	0.7196 (8)	0.9174 (8)	0.4115 (5)	0.0535 (17)
H3	0.6964	1.0099	0.4320	0.064*
C4	0.6668 (8)	0.8030 (10)	0.4630 (5)	0.070 (2)
H4	0.6106	0.8163	0.5168	0.084*
C5	0.7033 (9)	0.6629 (9)	0.4291 (6)	0.073 (2)
H5	0.6728	0.5809	0.4613	0.087*
C6	0.7820 (8)	0.6507 (7)	0.3504 (6)	0.0633 (19)
H6	0.8054	0.5598	0.3269	0.076*
C7	0.8286 (6)	0.7736 (6)	0.3038 (4)	0.0405 (13)
C8	0.9159 (6)	0.7661 (7)	0.2154 (4)	0.0408 (13)
C9	0.9646 (9)	0.6356 (7)	0.1766 (6)	0.0627 (19)
H9	0.9447	0.5484	0.2067	0.075*
C10	1.0418 (10)	0.6383 (10)	0.0936 (7)	0.081 (3)
H10	1.0713	0.5519	0.0663	0.097*
C11	1.0758 (8)	0.7647 (9)	0.0510 (5)	0.066 (2)
H11	1.1292	0.7669	−0.0048	0.080*
C12	1.0277 (8)	0.8924 (8)	0.0937 (5)	0.0601 (19)
H12	1.0495	0.9802	0.0651	0.072*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Ni1	0.0387 (2)	0.0456 (2)	0.0463 (2)	0.0000 (2)	−0.0004 (3)	0.0045 (3)
O1	0.042 (2)	0.065 (3)	0.044 (3)	−0.012 (2)	−0.0101 (19)	0.022 (2)
O2	0.0384 (19)	0.052 (2)	0.034 (2)	−0.0078 (19)	−0.0056 (16)	0.0150 (18)
O3	0.039 (2)	0.061 (2)	0.036 (2)	0.0098 (19)	−0.0144 (18)	−0.0128 (19)
O4	0.042 (2)	0.048 (2)	0.035 (2)	−0.0017 (18)	−0.0036 (17)	−0.0095 (18)
N1	0.043 (3)	0.045 (3)	0.032 (2)	−0.0063 (18)	0.006 (2)	−0.0005 (19)
N2	0.045 (3)	0.038 (2)	0.036 (3)	0.0049 (19)	0.008 (2)	0.002 (2)
C1	0.038 (3)	0.036 (3)	0.040 (3)	0.007 (3)	−0.004 (3)	0.004 (3)
C2	0.028 (3)	0.034 (3)	0.029 (3)	−0.002 (2)	−0.0031 (19)	0.005 (2)
C3	0.062 (4)	0.058 (4)	0.041 (4)	−0.005 (3)	0.016 (3)	0.005 (3)
C4	0.068 (4)	0.098 (6)	0.043 (4)	−0.024 (5)	0.015 (4)	0.011 (4)
C5	0.087 (5)	0.071 (5)	0.060 (4)	−0.034 (4)	0.011 (4)	0.021 (4)
C6	0.088 (5)	0.039 (3)	0.063 (4)	−0.022 (3)	0.004 (4)	−0.002 (3)
C7	0.040 (3)	0.045 (3)	0.037 (3)	−0.008 (3)	0.000 (3)	0.005 (2)
C8	0.045 (3)	0.046 (3)	0.031 (3)	0.008 (3)	0.000 (3)	−0.005 (2)
C9	0.089 (5)	0.041 (3)	0.058 (4)	0.012 (3)	−0.002 (4)	0.005 (3)
C10	0.096 (7)	0.073 (5)	0.073 (5)	0.040 (5)	0.009 (5)	−0.017 (5)
C11	0.091 (5)	0.070 (5)	0.037 (4)	0.028 (4)	0.012 (4)	0.003 (3)
C12	0.069 (5)	0.064 (4)	0.047 (4)	0.023 (3)	0.014 (3)	0.012 (3)

Geometric parameters (Å, º) top

Ni1—O4	2.162 (4)	C3—C4	1.376 (10)
Ni1—O2	2.157 (4)	C3—H3	0.930
Ni1—O1	2.180 (4)	C4—C5	1.425 (13)
Ni1—O3	2.169 (4)	C4—H4	0.930
Ni1—N2	2.242 (5)	C5—C6	1.335 (12)
Ni1—N1	2.246 (5)	C5—H5	0.930
O1—C2	1.242 (6)	C6—C7	1.385 (9)
O2—C1	1.251 (7)	C6—H6	0.930
O3—C1ⁱ	1.238 (6)	C7—C8	1.491 (8)
O4—C2ⁱ	1.237 (6)	C8—C9	1.404 (9)
N1—C3	1.322 (8)	C9—C10	1.372 (12)
N1—C7	1.328 (7)	C9—H9	0.930
N2—C8	1.343 (8)	C10—C11	1.353 (13)
N2—C12	1.346 (9)	C10—H10	0.930
C1—O3ⁱⁱ	1.238 (6)	C11—C12	1.402 (10)
C1—C2	1.554 (6)	C11—H11	0.930
C2—O4ⁱⁱ	1.237 (6)	C12—H12	0.930

O4—Ni1—O2	160.07 (14)	N1—C3—C4	125.0 (7)
O4—Ni1—O1	90.65 (14)	N1—C3—H3	117.5
O2—Ni1—O1	76.55 (13)	C4—C3—H3	117.5
O4—Ni1—O3	75.90 (14)	C3—C4—C5	115.9 (7)
O2—Ni1—O3	91.31 (15)	C3—C4—H4	122.0
O1—Ni1—O3	100.66 (17)	C5—C4—H4	122.0
O4—Ni1—N2	97.39 (17)	C6—C5—C4	119.3 (7)
O2—Ni1—N2	98.72 (18)	C6—C5—H5	120.4
O1—Ni1—N2	94.20 (18)	C4—C5—H5	120.4
O3—Ni1—N2	163.69 (17)	C5—C6—C7	119.8 (7)
O4—Ni1—N1	98.71 (17)	C5—C6—H6	120.1
O2—Ni1—N1	97.23 (17)	C7—C6—H6	120.1
O1—Ni1—N1	164.72 (18)	N1—C7—C6	122.7 (6)
O3—Ni1—N1	93.35 (18)	N1—C7—C8	115.3 (5)
N2—Ni1—N1	72.74 (17)	C6—C7—C8	122.0 (6)
C2—O1—Ni1	114.0 (3)	N2—C8—C9	120.3 (6)
C1—O2—Ni1	115.4 (4)	N2—C8—C7	116.6 (5)
C1ⁱ—O3—Ni1	115.4 (3)	C9—C8—C7	123.0 (6)
C2ⁱ—O4—Ni1	115.3 (3)	C8—C9—C10	119.2 (7)
C3—N1—C7	117.2 (5)	C8—C9—H9	120.4
C3—N1—Ni1	124.5 (4)	C10—C9—H9	120.4
C7—N1—Ni1	118.2 (4)	C11—C10—C9	121.0 (7)
C8—N2—C12	119.3 (5)	C11—C10—H10	119.5
C8—N2—Ni1	117.0 (4)	C9—C10—H10	119.5
C12—N2—Ni1	123.7 (4)	C10—C11—C12	117.7 (7)
O2—C1—O3ⁱⁱ	127.7 (5)	C10—C11—H11	121.2
O2—C1—C2	116.2 (5)	C12—C11—H11	121.2
O3ⁱⁱ—C1—C2	116.2 (5)	N2—C12—C11	122.4 (7)
O4ⁱⁱ—C2—O1	125.1 (5)	N2—C12—H12	118.8
O4ⁱⁱ—C2—C1	117.0 (4)	C11—C12—H12	118.8
O1—C2—C1	117.8 (4)

O4—Ni1—O1—C2	162.4 (4)	O1—Ni1—N2—C12	−7.8 (6)
O2—Ni1—O1—C2	−2.1 (4)	O3—Ni1—N2—C12	147.8 (6)
O3—Ni1—O1—C2	86.7 (4)	N1—Ni1—N2—C12	−179.8 (6)
N2—Ni1—O1—C2	−100.1 (4)	Ni1—O2—C1—O3ⁱⁱ	−179.5 (5)
N1—Ni1—O1—C2	−69.5 (8)	Ni1—O2—C1—C2	−0.7 (6)
O4—Ni1—O2—C1	−49.9 (7)	Ni1—O1—C2—O4ⁱⁱ	−175.8 (5)
O1—Ni1—O2—C1	1.4 (4)	Ni1—O1—C2—C1	2.5 (6)
O3—Ni1—O2—C1	−99.2 (4)	O2—C1—C2—O4ⁱⁱ	177.1 (6)
N2—Ni1—O2—C1	93.7 (4)	O3ⁱⁱ—C1—C2—O4ⁱⁱ	−3.9 (7)
N1—Ni1—O2—C1	167.2 (4)	O2—C1—C2—O1	−1.3 (7)
O4—Ni1—O3—C1ⁱ	3.6 (4)	O3ⁱⁱ—C1—C2—O1	177.7 (6)
O2—Ni1—O3—C1ⁱ	168.2 (4)	C7—N1—C3—C4	2.7 (11)
O1—Ni1—O3—C1ⁱ	91.6 (4)	Ni1—N1—C3—C4	179.3 (6)
N2—Ni1—O3—C1ⁱ	−63.7 (8)	N1—C3—C4—C5	−0.5 (11)
N1—Ni1—O3—C1ⁱ	−94.5 (4)	C3—C4—C5—C6	−1.4 (12)
O2—Ni1—O4—C2ⁱ	−52.8 (7)	C4—C5—C6—C7	1.0 (12)
O1—Ni1—O4—C2ⁱ	−102.2 (4)	C3—N1—C7—C6	−3.1 (9)
O3—Ni1—O4—C2ⁱ	−1.3 (4)	Ni1—N1—C7—C6	−179.9 (5)
N2—Ni1—O4—C2ⁱ	163.5 (4)	C3—N1—C7—C8	177.8 (6)
N1—Ni1—O4—C2ⁱ	89.9 (4)	Ni1—N1—C7—C8	0.9 (6)
O4—Ni1—N1—C3	−80.8 (6)	C5—C6—C7—N1	1.3 (11)
O2—Ni1—N1—C3	87.1 (6)	C5—C6—C7—C8	−179.6 (7)
O1—Ni1—N1—C3	152.0 (6)	C12—N2—C8—C9	3.2 (9)
O3—Ni1—N1—C3	−4.6 (6)	Ni1—N2—C8—C9	−174.3 (5)
N2—Ni1—N1—C3	−175.9 (6)	C12—N2—C8—C7	−178.8 (6)
O4—Ni1—N1—C7	95.7 (4)	Ni1—N2—C8—C7	3.6 (7)
O2—Ni1—N1—C7	−96.3 (4)	N1—C7—C8—N2	−3.0 (7)
O1—Ni1—N1—C7	−31.5 (9)	C6—C7—C8—N2	177.8 (6)
O3—Ni1—N1—C7	171.9 (4)	N1—C7—C8—C9	174.9 (6)
N2—Ni1—N1—C7	0.6 (4)	C6—C7—C8—C9	−4.3 (9)
O4—Ni1—N2—C8	−99.2 (5)	N2—C8—C9—C10	−3.7 (11)
O2—Ni1—N2—C8	92.6 (4)	C7—C8—C9—C10	178.5 (7)
O1—Ni1—N2—C8	169.6 (4)	C8—C9—C10—C11	2.4 (13)
O3—Ni1—N2—C8	−34.7 (9)	C9—C10—C11—C12	−0.9 (13)
N1—Ni1—N2—C8	−2.3 (4)	C8—N2—C12—C11	−1.7 (11)
O4—Ni1—N2—C12	83.4 (6)	Ni1—N2—C12—C11	175.7 (6)
O2—Ni1—N2—C12	−84.9 (6)	C10—C11—C12—N2	0.4 (12)

Symmetry codes: (i) x−1/2, −y+5/2, z; (ii) x+1/2, −y+5/2, z.

Experimental details

Crystal data
Chemical formula	[Ni(C₂O₄)(C₁₀H₈N₂)]
M_r	302.91
Crystal system, space group	Orthorhombic, Pna2₁
Temperature (K)	296
a, b, c (Å)	9.6486 (14), 9.2627 (14), 13.883 (2)
V (Å³)	1240.7 (3)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	1.57
Crystal size (mm)	0.12 × 0.10 × 0.06

Data collection
Diffractometer	Bruker APEXII CCD area-detector diffractometer
Absorption correction	Multi-scan (SADABS; Bruker, 2001)
T_min, T_max	0.834, 0.912
No. of measured, independent and observed [I > 2σ(I)] reflections	6146, 2114, 1810
R_int	0.030
(sin θ/λ)_max (Å⁻¹)	0.596

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.047, 0.154, 1.00
No. of reflections	2114
No. of parameters	173
No. of restraints	1
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.44, −0.44
Absolute structure	Flack (1983), 971 Friedel pairs
Absolute structure parameter	0.20 (3)

Computer programs: APEX2 (Bruker, 2004), SAINT-Plus (Bruker, 2001), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).

Acknowledgements

The authors are grateful for financial support from the Scientific Research Foundation of Outstanding Talented Persons of Henan Province (grant No. 74200510014).

References

Bruker (2001). SADABS and SAINT-Plus. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Bruker (2004). APEX2. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Deguenon, D., Bernardinelli, G., Tuchagues, J. P. & Castan, P. (1990). Inorg. Chem. 29, 3031–3039. CSD CrossRef CAS Web of Science Google Scholar
Eddaoudi, M., Kim, J., Wachter, J. B., Chae, H. K., Keeffe, M. O. & Yaghi, O. M. (2001). J. Am. Chem. Soc. 123, 4368-4369. Web of Science CSD CrossRef PubMed CAS Google Scholar
Flack, H. D. (1983). Acta Cryst. A39, 876–881. CrossRef CAS Web of Science IUCr Journals Google Scholar
Fun, H.-K., Shanmuga Sundara Raj, S., Fang, X., Zheng, L.-M. & Xin, X.-Q. (1999). Acta Cryst. C55, 903–905. Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
Hong, C. S. & Do, Y. (1997). Inorg. Chem. 36, 5684–5685. CSD CrossRef PubMed CAS Web of Science Google Scholar
Li, L. L., Lin, K. J., Ho, C. J., Sun, C. P. & Yang, H. D. (2006). Chem. Commun. pp. 1286–1287. Web of Science CSD CrossRef Google Scholar
Liang, M., Sun, Y. Q., Liao, D. Z., Jiang, Z. H., Yan, S. P. & Cheng, P. (2004). J. Coord. Chem. 57, 275–280. Web of Science CSD CrossRef CAS Google Scholar
Lin, X.-R., Ye, B.-Z., Liu, J.-S., Wei, C.-X. & Chen, J.-X. (2006). Acta Cryst. E62, m2130–m2132. Web of Science CSD CrossRef IUCr Journals Google Scholar
Luo, J.-H., Hong, M.-C., Liang, Y.-C. & Cao, R. (2001). Acta Cryst. E57, m361–m362. Web of Science CSD CrossRef IUCr Journals Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Shi, J. M., Yin, H. L. & Wu, C. J. (2005). J. Coord. Chem. 58, 915–920. Web of Science CSD CrossRef CAS Google Scholar
Yu, J. H., Hou, Q., Bi, M. H., Lu, Z. L., Zhang, X., Qu, X. J., Lu, J. & Xu, J. Q. (2006). J. Mol. Struct. 800, 69–75. Web of Science CSD CrossRef CAS Google Scholar

This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.