trans-Diaqua­bis­[4-carboxy-5-carboxyl­ato-2-(pyridin-1-ium-4-yl)-1H-imidazol-1-ido-κ2N1,O5]cobalt(II)

Sun, L.; Huang, Y.H.; Chen, T.T.; Deng, H.

doi:10.1107/S1600536811032545

metal-organic compounds

CRYSTALLOGRAPHIC
COMMUNICATIONS

ISSN: 2056-9890

Volume 67| Part 9| September 2011| Page m1257

doi:10.1107/S1600536811032545

Open

access

trans-Diaquabis[4-carboxy-5-carboxylato-2-(pyridin-1-ium-4-yl)-1H-imidazol-1-ido-κ²N¹,O⁵]cobalt(II)

Lin Sun,^a Yu Hua Huang,^a Ting Ting Chen ^a and Hong Deng ^a ^*

^aSchool of Chemistry and Environment, South China Normal University, Guangzhou 510006, People's Republic of China
^*Correspondence e-mail: dh@scnu.edu.cn

(Received 8 July 2011; accepted 11 August 2011; online 17 August 2011)

In the title compound, [Co(C₁₀H₆N₃O₄)₂(H₂O)₂], the Co^II ion is coordinated by two O atoms of two water molecules, two imidazole nitrogen atoms and two carboxylate O atoms of the two trans-standing chelate ligands, displaying a distorted octahedral coordination geometry. A three-dimensional supramolecular framework is generated through N—H⋯O, O—H⋯N and O—H⋯O hydrogen-bonding interactions.

Related literature

For the chemistry of N-heterocyclic carboxylic acids, see: Peng et al. (2010 ); Liu et al. (2005 ). For the applications of 2-(pyridine-4-yl)-1H-4,5-imidazoledicarboxylic acid, see: Li, Liu et al. (2009 ); Sun et al. (2006 ); Li, Wu et al. (2009 ); Chen et al. (2010 ).

Experimental

Crystal data

[Co(C₁₀H₆N₃O₄)₂(H₂O)₂]
M_r = 559.32
Monoclinic, C 2/c
a = 7.4146 (17) Å
b = 20.190 (5) Å
c = 13.361 (3) Å
β = 97.383 (3)°
V = 1983.6 (8) Å³
Z = 4
Mo Kα radiation
μ = 0.95 mm⁻¹
T = 296 K
0.27 × 0.26 × 0.24 mm

Data collection

Bruker AXS SMART APEX CCD diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ) T_min = 0.775, T_max = 0.797
4997 measured reflections
1775 independent reflections
1480 reflections with I > 2σ(I)
R_int = 0.032

Refinement

R[F² > 2σ(F²)] = 0.035
wR(F²) = 0.088
S = 1.01
1775 reflections
181 parameters
3 restraints
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.27 e Å⁻³
Δρ_min = −0.43 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1W—H1WA⋯N2ⁱ	0.84 (2)	2.05 (2)	2.889 (3)	176 (4)
O1W—H1WB⋯O4ⁱⁱ	0.81 (2)	2.27 (2)	3.046 (3)	161 (4)
N3—H3⋯O4ⁱⁱⁱ	0.91 (3)	1.86 (3)	2.754 (3)	170 (3)
O3—H3A⋯O2	1.20 (4)	1.25 (4)	2.451 (3)	172 (3)
Symmetry codes: (i) $[-x+{\script{3\over 2}}, -y+{\script{1\over 2}}, -z+1]$ ; (ii) $[x+{\script{1\over 2}}, -y+{\script{1\over 2}}, z-{\script{1\over 2}}]$ ; (iii) $[-x+{\script{3\over 2}}, y-{\script{1\over 2}}, -z+{\script{3\over 2}}]$ .

Data collection: APEX2 (Bruker, 2004 ); cell refinement: SAINT (Bruker, 2004); data reduction: SAINT; 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/S1600536811032545/bt5574sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536811032545/bt5574Isup2.hkl

checkCIF report

Comment top

Mixed N– and O-donor organic ligands, such as 1H-benzimidazole-5-carboxylic acid, has been investigated and proved to be a good choice to costruct novel coordination polymers (Peng et al., 2010; Liu et al., 2005). Another hybrid molecule 2-(pyridine-4-yl)-1H-4,5-imidazoledicarboxylic acid exhibits diverse coordination modes for its abundant potential donor atoms (Li, Liu et al., 2009; Sun et al., 2006; Li, Wu et al., 2009; Chen et al., 2010). In this work, we employed 2-(pyridine-4-yl)-1H-4,5-imidazoledicarboxylic acid as the building blocks to synthesize the title compound under hydrothermal condition. The centre metal ion Coⁱⁱ lies on an inversion centre and is coordinated by two imidazole nitrogen atoms, two O atoms of two water molecules and two carboxylate O atoms of the two trans-standing chelate ligands, displaying a distorted octahedral coordination geometry. The bond distances of Co—O_w and Co—O_carboxylate are 2.092 (3)Å and 2.066 (3) Å, respectively. And the Co—N bond length is 2.168 (3)Å (Table 1). The dihedral angle between the pyridyl ring and the imidazole ring is about 13.98 (2)° (Table 1, Figure 1). Since there are many hydrogen bonding interactions, a three-dimensional supramolecular architecture is eventually formed via N—H···O, O—H···N and O—H···O hydrogen-bonding interactions (Table 2, Figure 2).

Related literature top

For the chemistry of N-heterocyclic carboxylic acids, see: Peng et al. (2010); Liu et al. (2005). For the applications of 2-(pyridine-4-yl)-1H-4,5-imidazoledicarboxylic acid, see: Li, Liu et al. (2009); Sun et al. (2006); Li, Wu et al. (2009); Chen et al. (2010).

Experimental top

A mixture of CoSO₄(0.4 mmol, 0.062 g) and 2-(pyridine-4-yl)-1H-4,5-imidazoledicarboxylic acid (0.5 mmol, 0.115 g) together with water (10 ml) was sealed in a 23 ml Teflon-lined stainless steel reactor and heated at 160°C under autogenous pressure for 96 h. Then the mixture was cooled down to room temperature at a rate of 5°C/h, and brown block crystals were obtained in a yield of 39% based on Co.

Computing details top

Data collection: APEX2 (Bruker, 2004); cell refinement: SAINT (Bruker, 2004); data reduction: SAINT (Bruker, 2004); 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 structure of (I), showing the atomic numbering scheme. Non-H atoms are shown as 50% probability displacement ellipsoids.
	Fig. 2. A packing view of (I) along the a axis, showing the hydrogen bonds.

trans-Diaquabis[4-carboxy-5-carboxylato-2-(pyridin-1-ium-4-yl)- 1H-imidazol-1-ido-κ²N¹,O⁵]cobalt(II) top

Crystal data top

[Co(C₁₀H₆N₃O₄)₂(H₂O)₂]	F(000) = 1140
M_r = 559.32	D_x = 1.873 Mg m⁻³
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2yc	Cell parameters from 1775 reflections
a = 7.4146 (17) Å	θ = 2.5–25.5°
b = 20.190 (5) Å	µ = 0.95 mm⁻¹
c = 13.361 (3) Å	T = 296 K
β = 97.383 (3)°	Block, brown
V = 1983.6 (8) Å³	0.27 × 0.26 × 0.24 mm
Z = 4

Data collection top

Bruker AXS SMART APEX CCD diffractometer	1775 independent reflections
Radiation source: fine-focus sealed tube	1480 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.032
ω scans	θ_max = 25.2°, θ_min = 2.0°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −8→8
T_min = 0.775, T_max = 0.797	k = −17→24
4997 measured reflections	l = −15→15

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)] = 0.035	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.088	H atoms treated by a mixture of independent and constrained refinement
S = 1.01	w = 1/[σ²(F_o²) + (0.034P)² + 5.2791P] where P = (F_o² + 2F_c²)/3
1775 reflections	(Δ/σ)_max = 0.021
181 parameters	Δρ_max = 0.27 e Å⁻³
3 restraints	Δρ_min = −0.43 e Å⁻³

Crystal data top

[Co(C₁₀H₆N₃O₄)₂(H₂O)₂]	V = 1983.6 (8) Å³
M_r = 559.32	Z = 4
Monoclinic, C2/c	Mo Kα radiation
a = 7.4146 (17) Å	µ = 0.95 mm⁻¹
b = 20.190 (5) Å	T = 296 K
c = 13.361 (3) Å	0.27 × 0.26 × 0.24 mm
β = 97.383 (3)°

Data collection top

Bruker AXS SMART APEX CCD diffractometer	1775 independent reflections
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	1480 reflections with I > 2σ(I)
T_min = 0.775, T_max = 0.797	R_int = 0.032
4997 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.035	3 restraints
wR(F²) = 0.088	H atoms treated by a mixture of independent and constrained refinement
S = 1.01	Δρ_max = 0.27 e Å⁻³
1775 reflections	Δρ_min = −0.43 e Å⁻³
181 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
C1	0.9792 (4)	0.32925 (12)	0.57368 (19)	0.0187 (6)
C2	0.8527 (4)	0.34198 (12)	0.63981 (19)	0.0193 (6)
C3	0.8791 (3)	0.23737 (12)	0.62348 (19)	0.0178 (5)
C4	0.8456 (3)	0.16716 (13)	0.63859 (19)	0.0193 (6)
C5	0.9082 (4)	0.11718 (14)	0.5791 (2)	0.0257 (6)
H5	0.9695	0.1279	0.5248	0.031*
C6	0.8781 (4)	0.05252 (15)	0.6016 (2)	0.0332 (7)
H6	0.9176	0.0193	0.5613	0.040*
C7	0.7298 (4)	0.08204 (14)	0.7376 (2)	0.0282 (7)
H7	0.6702	0.0695	0.7918	0.034*
C8	0.7511 (4)	0.14764 (13)	0.7177 (2)	0.0254 (6)
H8	0.7026	0.1795	0.7569	0.031*
C9	1.0837 (4)	0.37354 (13)	0.5147 (2)	0.0234 (6)
C10	0.7965 (4)	0.40581 (13)	0.6804 (2)	0.0240 (6)
Co1	1.2500	0.2500	0.5000	0.02030 (17)
N1	0.9989 (3)	0.26264 (10)	0.56502 (16)	0.0176 (5)
N2	0.7881 (3)	0.28357 (10)	0.67008 (16)	0.0203 (5)
N3	0.7934 (3)	0.03578 (12)	0.68026 (19)	0.0290 (6)
H3	0.779 (4)	−0.0073 (16)	0.697 (2)	0.035*
O1	1.1926 (3)	0.34767 (9)	0.46237 (15)	0.0295 (5)
O2	1.0579 (3)	0.43564 (9)	0.51720 (17)	0.0358 (5)
O3	0.8438 (3)	0.45907 (9)	0.63801 (17)	0.0376 (6)
O4	0.7109 (3)	0.40657 (10)	0.75400 (16)	0.0330 (5)
O1W	1.1046 (3)	0.21633 (13)	0.36503 (16)	0.0390 (6)
H1WA	0.990 (2)	0.2183 (19)	0.356 (3)	0.058*
H1WB	1.139 (4)	0.1901 (16)	0.326 (2)	0.058*
H3A	0.940 (5)	0.4481 (18)	0.574 (3)	0.058*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
C1	0.0225 (14)	0.0126 (13)	0.0219 (14)	0.0016 (11)	0.0061 (11)	0.0013 (10)
C2	0.0237 (14)	0.0142 (13)	0.0208 (14)	0.0007 (10)	0.0061 (11)	0.0008 (10)
C3	0.0203 (13)	0.0141 (13)	0.0197 (13)	−0.0001 (10)	0.0048 (10)	0.0018 (10)
C4	0.0196 (14)	0.0175 (14)	0.0207 (14)	−0.0002 (11)	0.0019 (10)	0.0022 (11)
C5	0.0315 (15)	0.0212 (15)	0.0262 (15)	−0.0021 (12)	0.0106 (12)	0.0008 (11)
C6	0.0450 (18)	0.0211 (15)	0.0357 (18)	−0.0007 (13)	0.0136 (14)	−0.0048 (13)
C7	0.0337 (17)	0.0229 (15)	0.0304 (16)	−0.0024 (12)	0.0127 (13)	0.0049 (12)
C8	0.0307 (15)	0.0193 (14)	0.0285 (15)	0.0002 (12)	0.0124 (12)	0.0002 (12)
C9	0.0269 (15)	0.0187 (14)	0.0259 (15)	0.0008 (11)	0.0081 (12)	0.0029 (11)
C10	0.0260 (15)	0.0192 (14)	0.0280 (16)	0.0015 (12)	0.0076 (12)	−0.0032 (11)
Co1	0.0246 (3)	0.0161 (3)	0.0218 (3)	0.0021 (2)	0.0090 (2)	0.0006 (2)
N1	0.0215 (11)	0.0137 (11)	0.0187 (11)	0.0008 (9)	0.0065 (9)	0.0009 (8)
N2	0.0229 (12)	0.0159 (11)	0.0235 (12)	0.0006 (9)	0.0079 (9)	0.0007 (9)
N3	0.0361 (14)	0.0144 (12)	0.0375 (15)	−0.0041 (11)	0.0083 (11)	0.0038 (11)
O1	0.0361 (12)	0.0200 (10)	0.0365 (12)	0.0046 (9)	0.0201 (9)	0.0075 (9)
O2	0.0500 (14)	0.0132 (10)	0.0498 (14)	0.0029 (9)	0.0275 (11)	0.0058 (9)
O3	0.0600 (15)	0.0148 (10)	0.0439 (13)	0.0026 (10)	0.0285 (11)	−0.0002 (9)
O4	0.0425 (13)	0.0223 (11)	0.0383 (12)	0.0023 (9)	0.0211 (10)	−0.0056 (9)
O1W	0.0258 (11)	0.0621 (17)	0.0296 (12)	0.0044 (11)	0.0056 (10)	−0.0179 (11)

Geometric parameters (Å, º) top

C1—N1	1.359 (3)	C8—H8	0.9300
C1—C2	1.393 (4)	C9—O1	1.248 (3)
C1—C9	1.475 (4)	C9—O2	1.269 (3)
C2—N2	1.354 (3)	C10—O4	1.237 (3)
C2—C10	1.479 (4)	C10—O3	1.285 (3)
C3—N2	1.350 (3)	Co1—O1ⁱ	2.0659 (19)
C3—N1	1.355 (3)	Co1—O1	2.0659 (19)
C3—C4	1.458 (3)	Co1—O1Wⁱ	2.092 (2)
C4—C8	1.398 (4)	Co1—O1W	2.092 (2)
C4—C5	1.400 (4)	Co1—N1ⁱ	2.169 (2)
C5—C6	1.365 (4)	Co1—N1	2.169 (2)
C5—H5	0.9300	N3—H3	0.91 (3)
C6—N3	1.335 (4)	O2—H3A	1.25 (4)
C6—H6	0.9300	O3—H3A	1.20 (4)
C7—N3	1.332 (4)	O1W—H1WA	0.841 (18)
C7—C8	1.364 (4)	O1W—H1WB	0.810 (18)
C7—H7	0.9300

N1—C1—C2	109.0 (2)	O3—C10—C2	117.5 (2)
N1—C1—C9	119.0 (2)	O1ⁱ—Co1—O1	180.00 (11)
C2—C1—C9	132.0 (2)	O1ⁱ—Co1—O1Wⁱ	91.89 (9)
N2—C2—C1	108.8 (2)	O1—Co1—O1Wⁱ	88.11 (9)
N2—C2—C10	121.5 (2)	O1ⁱ—Co1—O1W	88.11 (9)
C1—C2—C10	129.6 (2)	O1—Co1—O1W	91.89 (9)
N2—C3—N1	114.1 (2)	O1Wⁱ—Co1—O1W	180.0
N2—C3—C4	120.3 (2)	O1ⁱ—Co1—N1ⁱ	79.89 (7)
N1—C3—C4	125.6 (2)	O1—Co1—N1ⁱ	100.11 (7)
C8—C4—C5	117.5 (2)	O1Wⁱ—Co1—N1ⁱ	90.55 (8)
C8—C4—C3	119.3 (2)	O1W—Co1—N1ⁱ	89.45 (8)
C5—C4—C3	123.2 (2)	O1ⁱ—Co1—N1	100.11 (7)
C6—C5—C4	119.2 (3)	O1—Co1—N1	79.89 (7)
C6—C5—H5	120.4	O1Wⁱ—Co1—N1	89.45 (8)
C4—C5—H5	120.4	O1W—Co1—N1	90.55 (8)
N3—C6—C5	121.5 (3)	N1ⁱ—Co1—N1	180.0
N3—C6—H6	119.2	C3—N1—C1	103.8 (2)
C5—C6—H6	119.2	C3—N1—Co1	147.82 (17)
N3—C7—C8	120.7 (3)	C1—N1—Co1	104.92 (16)
N3—C7—H7	119.7	C3—N2—C2	104.3 (2)
C8—C7—H7	119.7	C7—N3—C6	120.8 (3)
C7—C8—C4	120.2 (3)	C7—N3—H3	118 (2)
C7—C8—H8	119.9	C6—N3—H3	121 (2)
C4—C8—H8	119.9	C9—O1—Co1	113.00 (17)
O1—C9—O2	122.6 (2)	C9—O2—H3A	109.5 (17)
O1—C9—C1	117.9 (2)	C10—O3—H3A	112.3 (17)
O2—C9—C1	119.6 (2)	Co1—O1W—H1WA	121 (2)
O4—C10—O3	122.5 (2)	Co1—O1W—H1WB	127 (2)
O4—C10—C2	120.0 (2)	H1WA—O1W—H1WB	109 (3)

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

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O1W—H1WA···N2ⁱⁱ	0.84 (2)	2.05 (2)	2.889 (3)	176 (4)
O1W—H1WB···O4ⁱⁱⁱ	0.81 (2)	2.27 (2)	3.046 (3)	161 (4)
N3—H3···O4^iv	0.91 (3)	1.86 (3)	2.754 (3)	170 (3)
O3—H3A···O2	1.20 (4)	1.25 (4)	2.451 (3)	172 (3)

Symmetry codes: (ii) −x+3/2, −y+1/2, −z+1; (iii) x+1/2, −y+1/2, z−1/2; (iv) −x+3/2, y−1/2, −z+3/2.

Experimental details

Crystal data
Chemical formula	[Co(C₁₀H₆N₃O₄)₂(H₂O)₂]
M_r	559.32
Crystal system, space group	Monoclinic, C2/c
Temperature (K)	296
a, b, c (Å)	7.4146 (17), 20.190 (5), 13.361 (3)
β (°)	97.383 (3)
V (Å³)	1983.6 (8)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.95
Crystal size (mm)	0.27 × 0.26 × 0.24

Data collection
Diffractometer	Bruker AXS SMART APEX CCD diffractometer
Absorption correction	Multi-scan (SADABS; Sheldrick, 1996)
T_min, T_max	0.775, 0.797
No. of measured, independent and observed [I > 2σ(I)] reflections	4997, 1775, 1480
R_int	0.032
(sin θ/λ)_max (Å⁻¹)	0.599

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.035, 0.088, 1.01
No. of reflections	1775
No. of parameters	181
No. of restraints	3
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.27, −0.43

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

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O1W—H1WA···N2ⁱ	0.841 (18)	2.050 (19)	2.889 (3)	176 (4)
O1W—H1WB···O4ⁱⁱ	0.810 (18)	2.27 (2)	3.046 (3)	161 (4)
N3—H3···O4ⁱⁱⁱ	0.91 (3)	1.86 (3)	2.754 (3)	170 (3)
O3—H3A···O2	1.20 (4)	1.25 (4)	2.451 (3)	172 (3)

Symmetry codes: (i) −x+3/2, −y+1/2, −z+1; (ii) x+1/2, −y+1/2, z−1/2; (iii) −x+3/2, y−1/2, −z+3/2.

Acknowledgements

The authors acknowledge South China Normal University and the National Natural Science Foundation of China (grant No. 20871048) for supporting this work.

References

Bruker (2004). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Chen, L. Z., Huang, Y., Xiong, R. & Hu, H. J. (2010). J. Mol. Struct. 963, 16–21. Google Scholar
Li, X., Liu, W., Wu, B.-L. & Zhang, H.-Y. (2009). Acta Cryst. E65, m820–m821. Web of Science CSD CrossRef IUCr Journals Google Scholar
Li, X., Wu, B., Niu, C., Niu, Y. & Zhang, H. (2009). Cryst. Growth Des. 9, 3423–3431. Web of Science CSD CrossRef CAS Google Scholar
Liu, Z., Chen, Y., Liu, P., Wang, J. & Huang, M. H. (2005). J. Solid State Chem. 178, 2306–2312. CrossRef CAS Google Scholar
Peng, G., Qiu, Y. C., Liu, Z. H., Liu, B. & Deng, H. (2010). Cryst. Growth Des. 10, 114–121. Web of Science CSD CrossRef CAS Google Scholar
Sheldrick, G. M. (1996). SADABS. University of Göttingen, Germany. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Sun, T., Ma, J.-P., Huang, R.-Q. & Dong, Y.-B. (2006). Acta Cryst. E62, o2751–o2752. Web of Science CSD CrossRef 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.