catena-Poly[[bis­(nitrato-κO)copper(II)]-bis­[μ-1,4-bis­(pyridin-3-ylmeth­oxy)benzene-κ2N:N′]]

Zou, P.; Liu, Y.; Hou, G.-F.; Gao, J.-S.

doi:10.1107/S1600536811016096

metal-organic compounds

CRYSTALLOGRAPHIC
COMMUNICATIONS

ISSN: 2056-9890

Volume 67| Part 6| June 2011| Page m692

doi:10.1107/S1600536811016096

Open

access

catena-Poly[[bis(nitrato-κO)copper(II)]-bis[μ-1,4-bis(pyridin-3-ylmethoxy)benzene-κ²N:N′]]

Ping Zou,^a Ying Liu,^b,^c Guang-Feng Hou ^b and Jin-Sheng Gao ^b ^*

^aCollege of Life Science, Sichuan Agriculture University, Ya'an 625014, People's Republic of China, ^bCollege of Chemistry and Materials Science, Heilongjiang University, Harbin 150080, People's Republic of China, and ^cDepartment of Materials and Chemistry Engineering, Heilongjiang Institute of Technology, Harbin 150050, People's Republic of China
^*Correspondence e-mail: hgf1000@163.com

(Received 15 April 2011; accepted 28 April 2011; online 7 May 2011)

In the title compound, [Cu(NO₃)₂(C₁₈H₁₆N₂O₂)₂]_n, the Cu^II ion lies on an inversion center and is six-coordinated in a Jahn–Teller-distored octahedral geometry defined by four N atoms of the pyridine derivative forming a square plane, above and below which are the O atoms of the nitrate anion. The ligand links the metal atoms linto a linear chain running along the a axis. One of the nitrate O atoms is equally disordered over two sets of sites.

Related literature

For the synthesis and background to network structures built up from flexible pyridyl-based aromatic ligands and transition metals, see Liu et al. (2010a ,b ).

Experimental

Crystal data

[Cu(NO₃)₂(C₁₈H₁₆N₂O₂)₂]
M_r = 772.22
Monoclinic, P 2₁ /c
a = 8.4859 (17) Å
b = 17.030 (3) Å
c = 12.986 (4) Å
β = 116.22 (2)°
V = 1683.6 (7) Å³
Z = 2
Mo Kα radiation
μ = 0.72 mm⁻¹
T = 291 K
0.20 × 0.18 × 0.17 mm

Data collection

Rigaku R-AXIS RAPID diffractometer
Absorption correction: multi-scan (ABSCOR; Higashi, 1995 ) T_min = 0.867, T_max = 0.889
16256 measured reflections
3831 independent reflections
3067 reflections with I > 2σ(I)
R_int = 0.039

Refinement

R[F² > 2σ(F²)] = 0.037
wR(F²) = 0.097
S = 1.07
3831 reflections
251 parameters
12 restraints
H-atom parameters constrained
Δρ_max = 0.45 e Å⁻³
Δρ_min = −0.26 e Å⁻³

Data collection: RAPID-AUTO (Rigaku, 1998 ); cell refinement: RAPID-AUTO; data reduction: CrystalClear (Rigaku/MSC, 2002 ); 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.

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536811016096/ng5152sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536811016096/ng5152Isup2.hkl

checkCIF report

Comment top

The bridging pyridyl ligands can be used to construct interesting 0D to three-dimensional supramolecular architectures. Our group has reported some isolated molecule, chain, plane and three-dimensional network structures built up by flexible pyridyl-based aromatic ligands and transition metals. (Liu et al., 2010a; Liu et al., 2010b). As our continuing work for pyridyl ligands, we report here the synthesis and crystal structure of the title compound.

An asymmetric unit of the title compound consists of a 1,4-bis(pyridin-3-ylmethoxy)benzene molecule, a nitrate anion and a Cu^II cation (Figure 1). The Cu^II cations lie on the inversion centers and are six-coordinated in the Jahn-Teller distored octahedral geometry environments defined by four N atoms forming the square planes and two O atoms locating the polar axis.

In the crystal, ribbon structures along [2 0 1] direction are built up by heterocyclic ligands bridging Cu^II cations (Figure 2, Table 1).

Related literature top

For the synthesis and background to network structures built up from flexible pyridyl-based aromatic ligands and transition metals, see Liu et al. (2010a,b).

Experimental top

The 1,4-bis(pyridin-3-ylmethoxy)benzene ligand was synthesized as the reference method (Liu et al., 2010a): A mixture of 1,4-dihydroxybenzene (1.1 g, 10 mmol), 3-chloromethylpyridine hydrochloride (3.28 g, 20 mmol) and NaOH (1.6 g, 40 mmol) in acetonitrile (50 ml) was refluxed under nitrogen with stirring for 24 h. After cooling to room temperature, the solution was filtered and the residue was washed with acetonitrile for several times. The mixed filtrate was droped into 300 ml water solution to get the powder crude product. A total of 2.51 g (yield 86%) pure product was obtained by recrystallizing from the mixed solution of 10 ml water and 10 ml me thanol. The title compound was synthesized by reaction of 1,4-bis(pyridin-3-ylmethoxy)benzene ligand (0.29 g, 1.0 mmol) and Cu(NO₃)₂^.3H₂O (0.22 g, 1.0 mmol) in 5 ml water and 5 ml me thanol mixed solution. After filtration, blue block crystals suitable for X-ray diffraction were obtained by slow evaporation at room temperature for several days in 46% yield.

Computing details top

Data collection: RAPID-AUTO (Rigaku, 1998); cell refinement: RAPID-AUTO (Rigaku, 1998); data reduction: CrystalClear (Rigaku/MSC, 2002); 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 (Sheldrick, 2008).

Figures top

	Fig. 1. The molecular structure of the title compound, showing displacement ellipsoids at the 50% probability level for non-H atoms, disordered O4' atom has been omitted for clarity.
	Fig. 2. A partial packing view, showing the ribbon structure along [2 0 1] direction. Disordered O4' atoms and no involving H atoms have been omitted for clarity.

catena-Poly[[bis(nitrato-κO)copper(II)]-bis[µ-1,4- bis(pyridin-3-ylmethoxy)benzene-κ²N:N']] top

Crystal data top

[Cu(NO₃)₂(C₁₈H₁₆N₂O₂)₂]	F(000) = 798
M_r = 772.22	D_x = 1.523 Mg m⁻³
Monoclinic, P2₁/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 13022 reflections
a = 8.4859 (17) Å	θ = 3.4–27.4°
b = 17.030 (3) Å	µ = 0.72 mm⁻¹
c = 12.986 (4) Å	T = 291 K
β = 116.22 (2)°	Block, blue
V = 1683.6 (7) Å³	0.20 × 0.18 × 0.17 mm
Z = 2

Data collection top

Rigaku R-AXIS RAPID diffractometer	3831 independent reflections
Radiation source: fine-focus sealed tube	3067 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.039
ω scans	θ_max = 27.5°, θ_min = 3.4°
Absorption correction: multi-scan (ABSCOR; Higashi, 1995)	h = −11→10
T_min = 0.867, T_max = 0.889	k = −22→22
16256 measured reflections	l = −16→16

Refinement top

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) = 0.097	H-atom parameters constrained
S = 1.07	w = 1/[σ²(F_o²) + (0.0495P)² + 0.4137P] where P = (F_o² + 2F_c²)/3
3831 reflections	(Δ/σ)_max < 0.001
251 parameters	Δρ_max = 0.45 e Å⁻³
12 restraints	Δρ_min = −0.26 e Å⁻³

Crystal data top

[Cu(NO₃)₂(C₁₈H₁₆N₂O₂)₂]	V = 1683.6 (7) Å³
M_r = 772.22	Z = 2
Monoclinic, P2₁/c	Mo Kα radiation
a = 8.4859 (17) Å	µ = 0.72 mm⁻¹
b = 17.030 (3) Å	T = 291 K
c = 12.986 (4) Å	0.20 × 0.18 × 0.17 mm
β = 116.22 (2)°

Data collection top

Rigaku R-AXIS RAPID diffractometer	3831 independent reflections
Absorption correction: multi-scan (ABSCOR; Higashi, 1995)	3067 reflections with I > 2σ(I)
T_min = 0.867, T_max = 0.889	R_int = 0.039
16256 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.037	12 restraints
wR(F²) = 0.097	H-atom parameters constrained
S = 1.07	Δρ_max = 0.45 e Å⁻³
3831 reflections	Δρ_min = −0.26 e Å⁻³
251 parameters

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	Occ. (<1)
C1	−0.3511 (2)	0.87028 (12)	0.16557 (18)	0.0353 (4)
H1	−0.4698	0.8612	0.1432	0.042*
C2	−0.2290 (3)	0.82377 (13)	0.25037 (19)	0.0383 (5)
H2	−0.2657	0.7837	0.2833	0.046*
C3	−0.0520 (3)	0.83705 (12)	0.28601 (18)	0.0351 (4)
H3	0.0317	0.8065	0.3435	0.042*
C4	−0.0017 (2)	0.89662 (11)	0.23463 (17)	0.0303 (4)
C5	−0.1310 (2)	0.93984 (12)	0.14835 (18)	0.0325 (4)
H5	−0.0970	0.9788	0.1120	0.039*
C6	0.1879 (2)	0.91934 (13)	0.27306 (19)	0.0385 (5)
H6A	0.2070	0.9342	0.2073	0.046*
H6B	0.2181	0.9637	0.3252	0.046*
C7	0.4713 (2)	0.86583 (12)	0.39043 (19)	0.0372 (5)
C8	0.5671 (2)	0.80017 (12)	0.44675 (18)	0.0350 (4)
H8	0.5101	0.7526	0.4415	0.042*
C9	0.7480 (2)	0.80513 (12)	0.51103 (18)	0.0349 (4)
H9	0.8124	0.7609	0.5482	0.042*
C10	0.8320 (2)	0.87615 (12)	0.51957 (18)	0.0360 (5)
C11	0.7367 (3)	0.94163 (13)	0.4634 (2)	0.0419 (5)
H11	0.7937	0.9892	0.4690	0.050*
C12	0.5558 (3)	0.93666 (13)	0.3987 (2)	0.0425 (5)
H12	0.4917	0.9808	0.3611	0.051*
C13	1.1170 (2)	0.82248 (12)	0.63460 (19)	0.0381 (5)
H13A	1.1171	0.7852	0.5781	0.046*
H13B	1.0739	0.7963	0.6835	0.046*
C14	1.2990 (2)	0.85426 (11)	0.70499 (17)	0.0305 (4)
C15	1.4412 (3)	0.83865 (12)	0.68279 (19)	0.0375 (5)
H15	1.4282	0.8078	0.6205	0.045*
C16	1.6027 (3)	0.86992 (12)	0.75514 (19)	0.0377 (5)
H16	1.6998	0.8600	0.7418	0.045*
C17	1.6204 (2)	0.91564 (11)	0.84668 (18)	0.0319 (4)
H17	1.7306	0.9354	0.8955	0.038*
C18	1.3260 (2)	0.90220 (11)	0.79731 (16)	0.0300 (4)
H18	1.2301	0.9139	0.8113	0.036*
Cu1	−0.5000	1.0000	0.0000	0.03106 (12)
N1	−0.30485 (19)	0.92812 (9)	0.11430 (14)	0.0304 (3)
N2	1.48165 (18)	0.93268 (9)	0.86752 (13)	0.0279 (3)
N3	−0.8293 (2)	0.86505 (11)	−0.01848 (17)	0.0411 (4)
O1	0.29285 (18)	0.85382 (9)	0.32890 (17)	0.0579 (5)
O2	1.01067 (18)	0.88797 (9)	0.57993 (16)	0.0536 (5)
O3	−0.74035 (19)	0.92569 (8)	0.02595 (14)	0.0421 (4)
O4	−0.9828 (11)	0.8623 (6)	−0.035 (2)	0.085 (4)	0.49 (4)
O5	−0.7554 (2)	0.80297 (10)	−0.01836 (19)	0.0654 (5)
O4'	−0.9848 (9)	0.8748 (6)	−0.0923 (18)	0.080 (4)	0.51 (4)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
C1	0.0205 (9)	0.0423 (11)	0.0386 (11)	−0.0021 (8)	0.0088 (8)	−0.0068 (9)
C2	0.0323 (10)	0.0405 (11)	0.0392 (12)	−0.0036 (9)	0.0132 (9)	0.0031 (9)
C3	0.0270 (9)	0.0401 (11)	0.0304 (10)	0.0059 (8)	0.0056 (8)	0.0042 (8)
C4	0.0195 (8)	0.0351 (10)	0.0305 (10)	0.0041 (7)	0.0058 (7)	−0.0003 (8)
C5	0.0216 (9)	0.0352 (10)	0.0343 (10)	0.0040 (7)	0.0065 (8)	0.0048 (8)
C6	0.0194 (9)	0.0427 (11)	0.0436 (12)	0.0033 (8)	0.0049 (9)	0.0093 (9)
C7	0.0152 (8)	0.0442 (11)	0.0429 (12)	0.0024 (8)	0.0044 (8)	0.0069 (9)
C8	0.0236 (9)	0.0351 (10)	0.0415 (12)	−0.0008 (8)	0.0100 (9)	0.0045 (9)
C9	0.0233 (9)	0.0365 (10)	0.0360 (11)	0.0040 (8)	0.0050 (8)	0.0043 (8)
C10	0.0179 (8)	0.0424 (11)	0.0355 (11)	−0.0001 (8)	0.0008 (8)	0.0011 (9)
C11	0.0252 (10)	0.0369 (11)	0.0524 (14)	−0.0033 (8)	0.0069 (9)	0.0042 (10)
C12	0.0247 (10)	0.0383 (11)	0.0518 (13)	0.0057 (8)	0.0054 (9)	0.0119 (10)
C13	0.0216 (9)	0.0371 (10)	0.0417 (12)	0.0011 (8)	0.0012 (8)	−0.0056 (9)
C14	0.0206 (8)	0.0306 (9)	0.0308 (10)	0.0011 (7)	0.0028 (8)	−0.0006 (8)
C15	0.0323 (10)	0.0383 (11)	0.0383 (11)	0.0028 (8)	0.0123 (9)	−0.0087 (9)
C16	0.0251 (9)	0.0400 (11)	0.0489 (13)	0.0013 (8)	0.0172 (9)	−0.0063 (9)
C17	0.0184 (8)	0.0316 (9)	0.0385 (11)	0.0010 (7)	0.0059 (8)	−0.0019 (8)
C18	0.0164 (8)	0.0376 (10)	0.0299 (10)	0.0025 (7)	0.0046 (7)	−0.0007 (8)
Cu1	0.01777 (16)	0.03750 (19)	0.02666 (18)	0.00767 (13)	−0.00042 (12)	−0.00511 (14)
N1	0.0193 (7)	0.0353 (8)	0.0292 (8)	0.0048 (6)	0.0041 (6)	−0.0024 (7)
N2	0.0186 (7)	0.0312 (8)	0.0289 (8)	0.0032 (6)	0.0059 (6)	−0.0011 (6)
N3	0.0276 (9)	0.0427 (10)	0.0492 (11)	−0.0003 (7)	0.0136 (8)	0.0019 (8)
O1	0.0167 (7)	0.0448 (9)	0.0878 (14)	0.0030 (6)	0.0009 (8)	0.0187 (9)
O2	0.0205 (7)	0.0427 (9)	0.0697 (12)	−0.0023 (6)	−0.0055 (7)	0.0095 (8)
O3	0.0392 (8)	0.0356 (7)	0.0475 (9)	−0.0028 (6)	0.0154 (7)	−0.0007 (7)
O4	0.028 (2)	0.096 (4)	0.124 (9)	0.000 (2)	0.027 (4)	0.004 (5)
O5	0.0593 (11)	0.0374 (9)	0.0899 (15)	0.0023 (8)	0.0243 (11)	−0.0022 (9)
O4'	0.022 (2)	0.086 (4)	0.102 (8)	−0.005 (2)	0.001 (3)	−0.006 (4)

Geometric parameters (Å, º) top

C1—N1	1.341 (3)	C13—O2	1.413 (2)
C1—C2	1.380 (3)	C13—C14	1.505 (3)
C1—H1	0.9300	C13—H13A	0.9700
C2—C3	1.381 (3)	C13—H13B	0.9700
C2—H2	0.9300	C14—C18	1.383 (3)
C3—C4	1.381 (3)	C14—C15	1.385 (3)
C3—H3	0.9300	C15—C16	1.381 (3)
C4—C5	1.384 (3)	C15—H15	0.9300
C4—C6	1.509 (3)	C16—C17	1.373 (3)
C5—N1	1.354 (2)	C16—H16	0.9300
C5—H5	0.9300	C17—N2	1.351 (2)
C6—O1	1.412 (2)	C17—H17	0.9300
C6—H6A	0.9700	C18—N2	1.334 (2)
C6—H6B	0.9700	C18—H18	0.9300
C7—O1	1.380 (2)	Cu1—N2ⁱ	2.0153 (16)
C7—C12	1.383 (3)	Cu1—N2ⁱⁱ	2.0153 (16)
C7—C8	1.386 (3)	Cu1—N1	2.0669 (16)
C8—C9	1.389 (3)	Cu1—N1ⁱⁱⁱ	2.0669 (16)
C8—H8	0.9300	Cu1—O3	2.5460 (15)
C9—C10	1.383 (3)	N2—Cu1^iv	2.0153 (16)
C9—H9	0.9300	N3—O4	1.226 (7)
C10—O2	1.380 (2)	N3—O5	1.229 (2)
C10—C11	1.382 (3)	N3—O4'	1.253 (8)
C11—C12	1.389 (3)	N3—O3	1.259 (2)
C11—H11	0.9300	O4—O4'	0.773 (8)
C12—H12	0.9300

N1—C1—C2	122.43 (18)	H13A—C13—H13B	108.7
N1—C1—H1	118.8	C18—C14—C15	117.88 (17)
C2—C1—H1	118.8	C18—C14—C13	118.12 (17)
C1—C2—C3	119.7 (2)	C15—C14—C13	124.00 (18)
C1—C2—H2	120.1	C16—C15—C14	118.58 (19)
C3—C2—H2	120.1	C16—C15—H15	120.7
C2—C3—C4	118.72 (18)	C14—C15—H15	120.7
C2—C3—H3	120.6	C17—C16—C15	120.29 (18)
C4—C3—H3	120.6	C17—C16—H16	119.9
C3—C4—C5	118.58 (17)	C15—C16—H16	119.9
C3—C4—C6	122.69 (17)	N2—C17—C16	121.55 (17)
C5—C4—C6	118.65 (18)	N2—C17—H17	119.2
N1—C5—C4	123.05 (19)	C16—C17—H17	119.2
N1—C5—H5	118.5	N2—C18—C14	123.85 (17)
C4—C5—H5	118.5	N2—C18—H18	118.1
O1—C6—C4	107.81 (17)	C14—C18—H18	118.1
O1—C6—H6A	110.1	N2ⁱ—Cu1—N2ⁱⁱ	180.000 (1)
C4—C6—H6A	110.1	N2ⁱ—Cu1—N1	89.35 (6)
O1—C6—H6B	110.1	N2ⁱⁱ—Cu1—N1	90.65 (6)
C4—C6—H6B	110.1	N2ⁱ—Cu1—N1ⁱⁱⁱ	90.65 (6)
H6A—C6—H6B	108.5	N2ⁱⁱ—Cu1—N1ⁱⁱⁱ	89.35 (6)
O1—C7—C12	124.94 (18)	N1—Cu1—N1ⁱⁱⁱ	180.000 (1)
O1—C7—C8	115.08 (18)	N2ⁱ—Cu1—O3	86.22 (6)
C12—C7—C8	119.98 (17)	N2ⁱⁱ—Cu1—O3	93.78 (6)
C7—C8—C9	120.21 (19)	N1—Cu1—O3	92.59 (6)
C7—C8—H8	119.9	N1ⁱⁱⁱ—Cu1—O3	87.41 (6)
C9—C8—H8	119.9	C1—N1—C5	117.48 (16)
C10—C9—C8	119.67 (18)	C1—N1—Cu1	118.31 (12)
C10—C9—H9	120.2	C5—N1—Cu1	123.96 (13)
C8—C9—H9	120.2	C18—N2—C17	117.81 (16)
O2—C10—C11	114.98 (18)	C18—N2—Cu1^iv	118.98 (12)
O2—C10—C9	124.83 (18)	C17—N2—Cu1^iv	123.21 (13)
C11—C10—C9	120.18 (17)	O4—N3—O5	118.1 (5)
C10—C11—C12	120.20 (19)	O4—N3—O4'	36.3 (4)
C10—C11—H11	119.9	O5—N3—O4'	118.6 (4)
C12—C11—H11	119.9	O4—N3—O3	119.1 (5)
C7—C12—C11	119.76 (19)	O5—N3—O3	120.22 (18)
C7—C12—H12	120.1	O4'—N3—O3	117.2 (5)
C11—C12—H12	120.1	C7—O1—C6	117.53 (16)
O2—C13—C14	106.10 (16)	C10—O2—C13	117.89 (16)
O2—C13—H13A	110.5	N3—O3—Cu1	134.44 (13)
C14—C13—H13A	110.5	O4'—O4—N3	73.8 (10)
O2—C13—H13B	110.5	O4—O4'—N3	69.9 (10)
C14—C13—H13B	110.5

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

Experimental details

Crystal data
Chemical formula	[Cu(NO₃)₂(C₁₈H₁₆N₂O₂)₂]
M_r	772.22
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	291
a, b, c (Å)	8.4859 (17), 17.030 (3), 12.986 (4)
β (°)	116.22 (2)
V (Å³)	1683.6 (7)
Z	2
Radiation type	Mo Kα
µ (mm⁻¹)	0.72
Crystal size (mm)	0.20 × 0.18 × 0.17

Data collection
Diffractometer	Rigaku R-AXIS RAPID diffractometer
Absorption correction	Multi-scan (ABSCOR; Higashi, 1995)
T_min, T_max	0.867, 0.889
No. of measured, independent and observed [I > 2σ(I)] reflections	16256, 3831, 3067
R_int	0.039
(sin θ/λ)_max (Å⁻¹)	0.649

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.037, 0.097, 1.07
No. of reflections	3831
No. of parameters	251
No. of restraints	12
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.45, −0.26

Computer programs: RAPID-AUTO (Rigaku, 1998), CrystalClear (Rigaku/MSC, 2002), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).

Acknowledgements

The authors thank the Youth Fundation of the Education Department of Sichuan Province, China (No. 08ZB031), Sichuan Agriculture University, Heilongjiang University and Heilongjiang Institute of Technology for supporting this work.

References

Higashi, T. (1995). ABSCOR. Rigaku Corporation, Tokyo, Japan. Google Scholar
Liu, Y., Yan, P.-F., Yu, Y.-H., Hou, G.-F. & Gao, J.-S. (2010a). Cryst. Growth Des. 10, 1559–1568. Web of Science CSD CrossRef CAS Google Scholar
Liu, Y., Yan, P.-F., Yu, Y.-H., Hou, G.-F. & Gao, J.-S. (2010b). Inorg. Chem. Commun. 13, 630–632. Web of Science CSD CrossRef CAS Google Scholar
Rigaku (1998). RAPID-AUTO. Rigaku Corporation, Tokyo, Japan. Google Scholar
Rigaku/MSC (2002). CrystalStructure. Rigaku/MSC Inc., The Woodlands, Texas, USA. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals 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.