Poly[bis­(μ2-5-n-butyl­tetra­zolato-κ2N1:N4)zinc(II)]

Tong, X.-L.; Liu, H.; Yu, Q.; Li, J.-R.

doi:10.1107/S160053680706518X

metal-organic compounds

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ISSN: 2056-9890

Volume 64| Part 1| January 2008| Page m132

https://doi.org/10.1107/S160053680706518X

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Poly[bis(μ₂-5-n-butyltetrazolato-κ²N¹:N⁴)zinc(II)]

Xiao-Lan Tong,^a Hao Liu,^a Qun Yu ^a and Jian-Rong Li ^a ^*

^aDepartment of Chemistry, Nankai University, Tianjin 300071, People's Republic of China
^*Correspondence e-mail: jianrongli@nankai.edu.cn

(Received 20 November 2007; accepted 3 December 2007; online 6 December 2007)

In the title complex, [Zn(C₅H₉N₄)₂]_n, the Zn^II center is coordinated by four N atoms of different tetrazolate ligands with a slightly distorted tetrahedral geometry [Zn—N distances and N—Zn—N angles are in the ranges 1.991 (2)–2.007 (2) Å and 104.22 (8)–116.13 (8)°, respectively]. Each ligand links two Zn^II atoms through its 1- and 4-position tetrazole N atoms, forming a single, fully connected three-dimensional framework with a diamond-like topology. In the crystal structure, the Zn⋯Zn separations across each tetrazole unit are 6.115 (2) and 6.134 (2) Å and the Zn⋯Zn⋯Zn angles are in the range 107.77 (8)–116.83 (8)°.

Related literature

For related literature, see: Li et al. (2007 ) and references therein; Wang et al. (2005 ); Ye et al. (2005 ).

Experimental

Crystal data

[Zn(C₅H₉N₄)₂]
M_r = 315.69
Orthorhombic, P 2₁ 2₁ 2₁
a = 9.6534 (19) Å
b = 10.096 (2) Å
c = 14.359 (3) Å
V = 1399.4 (5) Å³
Z = 4
Mo Kα radiation
μ = 1.76 mm⁻¹
T = 113 (2) K
0.24 × 0.22 × 0.22 mm

Data collection

Bruker SMART 1000 CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 1998 ) T_min = 0.978, T_max = 1.000 (expected range = 0.665–0.680)
17371 measured reflections
3325 independent reflections
3068 reflections with I > 2σ(I)
R_int = 0.032

Refinement

R[F² > 2σ(F²)] = 0.022
wR(F²) = 0.050
S = 1.02
3325 reflections
172 parameters
H-atom parameters constrained
Δρ_max = 0.50 e Å⁻³
Δρ_min = −0.35 e Å⁻³
Absolute structure: Flack (1983 ), 1405 Friedel pairs
Flack parameter: −0.012 (9)

Data collection: SMART (Bruker, 1998); cell refinement: SAINT (Bruker, 1998); data reduction: SHELXTL (Bruker, 1998); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Supporting information

Crystal structure: contains datablocks global, I. DOI: https://doi.org/10.1107/S160053680706518X/sf2013sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S160053680706518X/sf2013Isup2.hkl

checkCIF report

Comment top

As the analogue of carboxylic acid, it has been realised that 5-substituted tetrazolate-based organic ligands have great potential in generating coordination polymers with novel network topologies and interesting properties [Li et al., 2007 and references therein]. Recently, three Zn^II tetrazolate-based complexes having similar diamondoid structure to the title complex, [Zn(C₅H₉N₄)₂]_n: catena-[bis(µ₂-5-phenyltetrazolato-N,N''')-zinc(II)], catena-[bis(µ₂-5-(4'-amino-6'-pyridyl)tetrazolato-N,N''')-zinc(II)] (Ye et al., 2005) and catena-[bis(µ₂tetrazolato-N,N''')-zinc(II)] (Wang et al., 2005) were reported.

As shown in Fig. 1, in the title complex the Zn^II center locates at the crystallographically general position and is coordinated by four N atoms of distinct tetrazolate ligands. The coordination geometry is of slightly distorted tetrahedron with Zn—N distances and N—Zn—N angles being in the range of 1.991 (2)–2.007 (2) Å and 104.22 (8)–116.13 (8) °, respectively. Each ligand links two Zn^II atoms through its 1- and 4-position tetrazole N atoms to form a single three-dimensional diamond-like framework (Fig. 2). In the structure, the Zn—Zn separations across each tetrazole moiety are 6.115 (2) and 6.134 (2) Å and the Zn—Zn—Zn angles are revealed to range from 107.77 (8) to 116.83 (8) °.

Related literature top

For related literature, see: Li et al. (2007) and references therein; Wang et al. (2005); Ye et al. (2005).

Experimental top

A mixture of ZnCl₂ (27 mg, 0.2 mmol), NaN₃ (33 mg, 0.5 mmol) and valeronitrile (33 mg, 0.4 mmol) in 10 ml of water was sealed in a Teflon-lined stainless-steel Parr bomb that was heated at 373 K for 48 h. Colorless crystals of the title compound were collected after the bomb was allowed to cool to room temperature spontaneously. Yield, 30% with respect to Zn^II. Caution: Metal azides may be explosive. Although we have met no problems in this work, only a small amount of them should be prepared and handled with great caution.

Structure description top

For related literature, see: Li et al. (2007) and references therein; Wang et al. (2005); Ye et al. (2005).

Computing details top

Data collection: SMART (Bruker, 1998); cell refinement: SMART (Bruker, 1998); data reduction: SHELXTL (Bruker, 1998); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Bruker, 1998); software used to prepare material for publication: SHELXTL (Bruker, 1998).

Figures top

	Fig. 1. View of coordination environments of Zn^II and ligand in the title complex with 40% displacement probability. [Herein, labelled atoms A—D correspond to symmetry oprations i-iv, respectively. (i) = 1/2 + x, -3/2 - y, -z; (ii) = -x, 1/2 + y, -1/2 - z; (iii) = -x, -1/2 + y, -1/2 - z and (iv) = -1/2 + x, -3/2 - y, -z]
	Fig. 2. three-dimensional structure of the title compound with butyl groups omitted for clarity.

Poly[bis(µ₂-5-n-butyltetrazolato-κ²N¹:N⁴)zinc(II)] top

Crystal data top

[Zn(C₅H₉N₄)₂]	F(000) = 656
M_r = 315.69	D_x = 1.498 Mg m⁻³
Orthorhombic, P2₁2₁2₁	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2ab	Cell parameters from 5045 reflections
a = 9.6534 (19) Å	θ = 2.8–27.9°
b = 10.096 (2) Å	µ = 1.76 mm⁻¹
c = 14.359 (3) Å	T = 113 K
V = 1399.4 (5) Å³	Block, colorless
Z = 4	0.24 × 0.22 × 0.22 mm

Data collection top

Bruker Smart 1000 CCD area-detector diffractometer	3325 independent reflections
Radiation source: fine-focus sealed tube	3068 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.032
φ and ω scan	θ_max = 27.9°, θ_min = 2.8°
Absorption correction: multi-scan (SADABS; Bruker, 1998)	h = −11→12
T_min = 0.978, T_max = 1.000	k = −13→13
17371 measured reflections	l = −18→18

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)] = 0.022	H-atom parameters constrained
wR(F²) = 0.050	w = 1/[σ²(F_o²) + (0.0274P)²] where P = (F_o² + 2F_c²)/3
S = 1.02	(Δ/σ)_max = 0.001
3325 reflections	Δρ_max = 0.50 e Å⁻³
172 parameters	Δρ_min = −0.35 e Å⁻³
0 restraints	Absolute structure: Flack (1983), 1405 Friedel pairs
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: −0.012 (9)

Crystal data top

[Zn(C₅H₉N₄)₂]	V = 1399.4 (5) Å³
M_r = 315.69	Z = 4
Orthorhombic, P2₁2₁2₁	Mo Kα radiation
a = 9.6534 (19) Å	µ = 1.76 mm⁻¹
b = 10.096 (2) Å	T = 113 K
c = 14.359 (3) Å	0.24 × 0.22 × 0.22 mm

Data collection top

Bruker Smart 1000 CCD area-detector diffractometer	3325 independent reflections
Absorption correction: multi-scan (SADABS; Bruker, 1998)	3068 reflections with I > 2σ(I)
T_min = 0.978, T_max = 1.000	R_int = 0.032
17371 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.022	H-atom parameters constrained
wR(F²) = 0.050	Δρ_max = 0.50 e Å⁻³
S = 1.02	Δρ_min = −0.35 e Å⁻³
3325 reflections	Absolute structure: Flack (1983), 1405 Friedel pairs
172 parameters	Absolute structure parameter: −0.012 (9)
0 restraints

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
Zn1	−0.029407 (19)	−0.736890 (17)	−0.131493 (12)	0.01072 (6)
C1	−0.26406 (18)	−0.79890 (17)	0.00726 (12)	0.0128 (4)
C2	−0.2305 (2)	−0.94018 (19)	0.02652 (15)	0.0211 (4)
H2A	−0.2072	−0.9498	0.0919	0.025*
H2B	−0.1497	−0.9653	−0.0096	0.025*
C3	−0.3495 (2)	−1.03381 (19)	0.00312 (17)	0.0294 (5)
H3A	−0.3606	−1.0382	−0.0639	0.035*
H3B	−0.4347	−0.9993	0.0294	0.035*
C4	−0.3233 (3)	−1.1747 (2)	0.0416 (2)	0.0495 (7)
H4A	−0.2441	−1.2133	0.0101	0.059*
H4B	−0.3018	−1.1693	0.1075	0.059*
C5	−0.4459 (3)	−1.2612 (2)	0.0281 (2)	0.0636 (8)
H5A	−0.4274	−1.3472	0.0538	0.085*
H5B	−0.4652	−1.2695	−0.0373	0.085*
H5C	−0.5245	−1.2230	0.0590	0.085*
C6	0.04569 (18)	−0.97174 (16)	−0.25457 (11)	0.0131 (4)
C7	0.19069 (19)	−0.92793 (18)	−0.27100 (14)	0.0168 (4)
H7A	0.2021	−0.8392	−0.2463	0.020*
H7B	0.2073	−0.9240	−0.3376	0.020*
C8	0.29893 (19)	−1.01919 (19)	−0.22630 (15)	0.0226 (4)
H8A	0.2883	−1.1079	−0.2512	0.027*
H8B	0.2828	−1.0232	−0.1597	0.027*
C9	0.4475 (2)	−0.9711 (2)	−0.24428 (16)	0.0313 (5)
H9A	0.5121	−1.0369	−0.2210	0.038*
H9B	0.4619	−0.9629	−0.3109	0.038*
C10	0.4783 (2)	−0.8388 (2)	−0.1982 (2)	0.0468 (7)
H10A	0.5718	−0.8128	−0.2120	0.070*
H10B	0.4673	−0.8470	−0.1320	0.070*
H10C	0.4154	−0.7729	−0.2214	0.070*
N1	−0.19539 (15)	−0.71806 (14)	−0.05010 (10)	0.0135 (3)
N2	−0.25827 (17)	−0.59748 (15)	−0.04447 (12)	0.0188 (4)
N3	−0.36058 (17)	−0.60558 (15)	0.01261 (11)	0.0177 (3)
N4	−0.36690 (14)	−0.73163 (15)	0.04700 (10)	0.0137 (3)
N5	−0.04611 (16)	−0.90468 (13)	−0.20430 (10)	0.0131 (3)
N6	−0.16579 (16)	−0.97651 (15)	−0.20460 (11)	0.0162 (3)
N7	−0.14673 (16)	−1.08254 (16)	−0.25271 (11)	0.0162 (3)
N8	−0.01317 (16)	−1.08258 (14)	−0.28558 (10)	0.0136 (3)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Zn1	0.01061 (9)	0.01059 (9)	0.01096 (9)	−0.00005 (7)	0.00044 (8)	0.00010 (7)
C1	0.0115 (8)	0.0141 (9)	0.0126 (8)	0.0008 (6)	−0.0007 (7)	−0.0011 (7)
C2	0.0235 (11)	0.0146 (10)	0.0250 (10)	0.0049 (8)	0.0080 (9)	0.0031 (8)
C3	0.0306 (12)	0.0158 (11)	0.0418 (14)	−0.0035 (9)	0.0143 (10)	−0.0064 (9)
C4	0.0491 (16)	0.0252 (13)	0.074 (2)	0.0053 (12)	0.0047 (16)	−0.0033 (13)
C5	0.066 (2)	0.0236 (13)	0.071 (2)	−0.0005 (14)	0.0079 (17)	0.0005 (14)
C6	0.0151 (9)	0.0116 (8)	0.0126 (8)	0.0030 (7)	−0.0003 (8)	0.0003 (6)
C7	0.0139 (9)	0.0140 (9)	0.0223 (10)	−0.0017 (7)	0.0028 (8)	−0.0055 (8)
C8	0.0185 (10)	0.0204 (10)	0.0288 (11)	0.0016 (8)	−0.0013 (9)	−0.0045 (8)
C9	0.0156 (11)	0.0356 (12)	0.0425 (13)	0.0034 (9)	−0.0011 (10)	−0.0062 (10)
C10	0.0216 (12)	0.0350 (13)	0.074 (2)	−0.0046 (11)	−0.0066 (15)	−0.0078 (13)
N1	0.0142 (7)	0.0127 (8)	0.0136 (7)	0.0004 (6)	0.0014 (6)	−0.0001 (6)
N2	0.0200 (8)	0.0135 (8)	0.0229 (9)	0.0030 (6)	0.0073 (7)	0.0021 (7)
N3	0.0213 (9)	0.0119 (8)	0.0200 (8)	0.0004 (6)	0.0064 (7)	0.0032 (6)
N4	0.0166 (7)	0.0105 (7)	0.0140 (7)	0.0007 (6)	0.0007 (6)	0.0014 (6)
N5	0.0123 (8)	0.0124 (7)	0.0146 (7)	−0.0003 (6)	0.0014 (6)	−0.0006 (6)
N6	0.0132 (8)	0.0161 (8)	0.0195 (8)	−0.0045 (6)	0.0017 (7)	−0.0047 (7)
N7	0.0129 (8)	0.0194 (8)	0.0162 (8)	−0.0011 (6)	0.0027 (7)	−0.0027 (6)
N8	0.0124 (8)	0.0141 (7)	0.0143 (7)	−0.0016 (6)	0.0015 (6)	−0.0024 (6)

Geometric parameters (Å, º) top

Zn1—N1	1.9923 (15)	C6—C7	1.487 (2)
Zn1—N5	1.9971 (14)	C7—C8	1.534 (3)
Zn1—N8ⁱ	2.0035 (14)	C7—H7A	0.9700
Zn1—N4ⁱⁱ	2.0085 (14)	C7—H7B	0.9700
C1—N4	1.331 (2)	C8—C9	1.536 (3)
C1—N1	1.336 (2)	C8—H8A	0.9700
C1—C2	1.489 (3)	C8—H8B	0.9700
C2—C3	1.525 (3)	C9—C10	1.521 (3)
C2—H2A	0.9700	C9—H9A	0.9700
C2—H2B	0.9700	C9—H9B	0.9700
C3—C4	1.547 (3)	C10—H10A	0.9600
C3—H3A	0.9700	C10—H10B	0.9600
C3—H3B	0.9700	C10—H10C	0.9600
C4—C5	1.484 (3)	N1—N2	1.363 (2)
C4—H4A	0.9700	N2—N3	1.286 (2)
C4—H4B	0.9700	N3—N4	1.366 (2)
C5—H5A	0.9600	N4—Zn1ⁱⁱⁱ	2.0085 (14)
C5—H5B	0.9600	N5—N6	1.364 (2)
C5—H5C	0.9600	N6—N7	1.287 (2)
C6—N5	1.329 (2)	N7—N8	1.373 (2)
C6—N8	1.332 (2)	N8—Zn1^iv	2.0035 (14)

N1—Zn1—N5	108.85 (6)	C8—C7—H7A	108.9
N1—Zn1—N8ⁱ	116.07 (6)	C6—C7—H7B	108.9
N5—Zn1—N8ⁱ	111.41 (6)	C8—C7—H7B	108.9
N1—Zn1—N4ⁱⁱ	106.79 (6)	H7A—C7—H7B	107.7
N5—Zn1—N4ⁱⁱ	104.18 (6)	C7—C8—C9	112.09 (17)
N8ⁱ—Zn1—N4ⁱⁱ	108.77 (6)	C7—C8—H8A	109.2
N4—C1—N1	108.82 (16)	C9—C8—H8A	109.2
N4—C1—C2	124.86 (16)	C7—C8—H8B	109.2
N1—C1—C2	126.30 (16)	C9—C8—H8B	109.2
C1—C2—C3	112.90 (17)	H8A—C8—H8B	107.9
C1—C2—H2A	109.0	C10—C9—C8	112.78 (18)
C3—C2—H2A	109.0	C10—C9—H9A	109.0
C1—C2—H2B	109.0	C8—C9—H9A	109.0
C3—C2—H2B	109.0	C10—C9—H9B	109.0
H2A—C2—H2B	107.8	C8—C9—H9B	109.0
C2—C3—C4	111.6 (2)	H9A—C9—H9B	107.8
C2—C3—H3A	109.3	C9—C10—H10A	109.5
C4—C3—H3A	109.3	C9—C10—H10B	109.5
C2—C3—H3B	109.3	H10A—C10—H10B	109.5
C4—C3—H3B	109.3	C9—C10—H10C	109.5
H3A—C3—H3B	108.0	H10A—C10—H10C	109.5
C5—C4—C3	111.4 (2)	H10B—C10—H10C	109.5
C5—C4—H4A	109.4	C1—N1—N2	106.75 (14)
C3—C4—H4A	109.4	C1—N1—Zn1	134.64 (12)
C5—C4—H4B	109.4	N2—N1—Zn1	118.57 (11)
C3—C4—H4B	109.4	N3—N2—N1	108.85 (14)
H4A—C4—H4B	108.0	N2—N3—N4	108.89 (14)
C4—C5—H5A	109.5	C1—N4—N3	106.68 (14)
C4—C5—H5B	109.5	C1—N4—Zn1ⁱⁱⁱ	139.52 (13)
H5A—C5—H5B	109.5	N3—N4—Zn1ⁱⁱⁱ	113.61 (11)
C4—C5—H5C	109.5	C6—N5—N6	106.99 (14)
H5A—C5—H5C	109.5	C6—N5—Zn1	131.52 (12)
H5B—C5—H5C	109.5	N6—N5—Zn1	121.40 (11)
N5—C6—N8	108.99 (15)	N7—N6—N5	108.83 (14)
N5—C6—C7	124.24 (15)	N6—N7—N8	108.60 (14)
N8—C6—C7	126.77 (16)	C6—N8—N7	106.59 (14)
C6—C7—C8	113.35 (16)	C6—N8—Zn1^iv	139.87 (13)
C6—C7—H7A	108.9	N7—N8—Zn1^iv	113.40 (11)

N4—C1—C2—C3	60.4 (3)	N1—C1—N4—Zn1ⁱⁱⁱ	174.28 (14)
N1—C1—C2—C3	−121.4 (2)	C2—C1—N4—Zn1ⁱⁱⁱ	−7.2 (3)
C1—C2—C3—C4	−168.7 (2)	N2—N3—N4—C1	−0.44 (19)
C2—C3—C4—C5	173.6 (2)	N2—N3—N4—Zn1ⁱⁱⁱ	−176.38 (12)
N5—C6—C7—C8	114.1 (2)	N8—C6—N5—N6	−0.20 (19)
N8—C6—C7—C8	−64.9 (2)	C7—C6—N5—N6	−179.41 (16)
C6—C7—C8—C9	−179.85 (16)	N8—C6—N5—Zn1	176.40 (12)
C7—C8—C9—C10	65.2 (2)	C7—C6—N5—Zn1	−2.8 (3)
N4—C1—N1—N2	0.4 (2)	N1—Zn1—N5—C6	−166.75 (15)
C2—C1—N1—N2	−178.09 (17)	N8ⁱ—Zn1—N5—C6	64.01 (17)
N4—C1—N1—Zn1	177.93 (12)	N4ⁱⁱ—Zn1—N5—C6	−53.10 (16)
C2—C1—N1—Zn1	−0.5 (3)	N1—Zn1—N5—N6	9.43 (14)
N5—Zn1—N1—C1	46.63 (19)	N8ⁱ—Zn1—N5—N6	−119.81 (13)
N8ⁱ—Zn1—N1—C1	173.24 (16)	N4ⁱⁱ—Zn1—N5—N6	123.08 (13)
N4ⁱⁱ—Zn1—N1—C1	−65.30 (18)	C6—N5—N6—N7	0.2 (2)
N5—Zn1—N1—N2	−136.05 (13)	Zn1—N5—N6—N7	−176.78 (11)
N8ⁱ—Zn1—N1—N2	−9.44 (15)	N5—N6—N7—N8	−0.18 (19)
N4ⁱⁱ—Zn1—N1—N2	112.02 (13)	N5—C6—N8—N7	0.09 (18)
C1—N1—N2—N3	−0.7 (2)	C7—C6—N8—N7	179.28 (17)
Zn1—N1—N2—N3	−178.68 (12)	N5—C6—N8—Zn1^iv	175.30 (14)
N1—N2—N3—N4	0.7 (2)	C7—C6—N8—Zn1^iv	−5.5 (3)
N1—C1—N4—N3	0.01 (19)	N6—N7—N8—C6	0.06 (18)
C2—C1—N4—N3	178.52 (17)	N6—N7—N8—Zn1^iv	−176.58 (12)

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

Experimental details

Crystal data
Chemical formula	[Zn(C₅H₉N₄)₂]
M_r	315.69
Crystal system, space group	Orthorhombic, P2₁2₁2₁
Temperature (K)	113
a, b, c (Å)	9.6534 (19), 10.096 (2), 14.359 (3)
V (Å³)	1399.4 (5)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	1.76
Crystal size (mm)	0.24 × 0.22 × 0.22

Data collection
Diffractometer	Bruker Smart 1000 CCD area-detector
Absorption correction	Multi-scan (SADABS; Bruker, 1998)
T_min, T_max	0.978, 1.000
No. of measured, independent and observed [I > 2σ(I)] reflections	17371, 3325, 3068
R_int	0.032
(sin θ/λ)_max (Å⁻¹)	0.658

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.022, 0.050, 1.02
No. of reflections	3325
No. of parameters	172
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.50, −0.35
Absolute structure	Flack (1983), 1405 Friedel pairs
Absolute structure parameter	−0.012 (9)

Computer programs: SMART (Bruker, 1998), SHELXTL (Bruker, 1998), SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997).

Acknowledgements

The authors thank Nankai University for supporting this work.

References

Bruker (1998). SMART (Version 5.051), SAINT (Version 5.01), SADABS (Version 2.03) and SHELXTL (Version 6.1). Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Flack, H. D. (1983). Acta Cryst. A39, 876–881. CrossRef CAS Web of Science IUCr Journals Google Scholar
Li, J.-R., Tao, Y., Yu, Q. & Bu, X.-H. (2007). Chem. Commun. pp. 1527–1529. Web of Science CSD CrossRef Google Scholar
Sheldrick, G. M. (1997). SHELXL97 and SHELXS97. University of Göttingen, Germany. Google Scholar
Wang, X.-S., Tang, Y.-Z., Huang, X.-F., Qu, Z.-R., Che, C.-M., Chan, P. W. H. & Xiong, R.-G. (2005). Inorg. Chem. 44, 5278–5285. Web of Science CSD CrossRef PubMed CAS Google Scholar
Ye, Q., Li, Y.-H., Song, Y.-M., Huang, X.-F., Xiong, R.-G. & Xue, Z. (2005). Inorg. Chem. 44, 3618–3625. Web of Science CSD CrossRef PubMed CAS Google Scholar