Poly[disodium [diaqua­tri-μ2-oxalato-dimagnesium(II)]]

Chen, X.-A.; Song, F.-P.; Chang, X.-A.; Zang, H.-G.; Xiao, W.-Q.

doi:10.1107/S1600536808019508

metal-organic compounds

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ISSN: 2056-9890

Volume 64| Part 8| August 2008| Page m983

doi:10.1107/S1600536808019508

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Poly[disodium [diaquatri-μ₂-oxalato-dimagnesium(II)]]

Xue-An Chen,^a ^* Fang-Ping Song,^a Xin-An Chang,^a He-Gui Zang ^a and Wei-Qiang Xiao ^b

^aCollege of Materials Science and Engineering, Beijing University of Technology, Ping Le Yuan 100, Beijing 100124, People's Republic of China, and ^bInstitute of Microstructure and Properties of Advanced Materials, Beijing University of Technology, Ping Le Yuan 100, Beijing 100124, People's Republic of China
^*Correspondence e-mail: xueanchen@bjut.edu.cn

(Received 12 June 2008; accepted 27 June 2008; online 5 July 2008)

The title compound, {Na₂[Mg₂(C₂O₄)₃(H₂O)₂]}_n, is isotypic with its Co analogue. There are two crystallographically independent oxalate groups in the asymmetric unit, one lying on an inversion center and the other on a general position. Mg²⁺ ions are ligated by H₂O molecules and bridged by tri- and tetradentate oxalate ligands, forming ladder-like double chains that are held together via O—H⋯O hydrogen bonds, with Na⁺ cations located between the chains to balance the charge.

Related literature

For related literature, see: Audebrand et al. (2003 ); Brown & Altermatt (1985 ); Dean et al. (2004 ); Kolitsch (2004 ); Lethbridge et al. (2003 ); Lu et al. (2004 ); Miessen & Hoppe (1987 ); Price et al. (2000 ); Schefer & Grube (1995 ); Shannon (1976 ).

Experimental

Crystal data

Na₂[Mg₂(C₂O₄)₃(H₂O)₂]
M_r = 394.70
Monoclinic, P 2₁ /c
a = 5.8460 (12) Å
b = 15.726 (3) Å
c = 7.0190 (14) Å
β = 101.11 (3)°
V = 633.2 (2) Å³
Z = 2
Mo Kα radiation
μ = 0.34 mm⁻¹
T = 290 K
0.4 × 0.2 × 0.2 mm

Data collection

Rigaku AFC-7R diffractometer
Absorption correction: ψ scan (Kopfmann & Huber, 1968 ) T_min = 0.912, T_max = 0.943
2457 measured reflections
2280 independent reflections
2027 reflections with I > 2σ(I)
R_int = 0.029
3 standard reflections every 150 reflections intensity decay: 1.2%

Refinement

R[F² > 2σ(F²)] = 0.033
wR(F²) = 0.095
S = 1.11
2280 reflections
118 parameters
All H-atom parameters refined
Δρ_max = 0.54 e Å⁻³
Δρ_min = −0.56 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O7—H7a⋯O4ⁱ	0.78 (3)	2.06 (3)	2.8335 (13)	170 (2)
O7—H7b⋯O6ⁱⁱ	0.84 (3)	1.89 (3)	2.6952 (13)	162 (3)
Symmetry codes: (i) -x+1, -y+1, -z; (ii) $[x-1, -y+{\script{3\over 2}}, z-{\script{1\over 2}}]$ .

Data collection: AFC Diffractometer Control Software (Rigaku, 1994 $[Rigaku (1994). AFC Diffractometer Control Software. Rigaku Corporation, Tokyo, Japan.]$ ); cell refinement: AFC Diffractometer Control Software; data reduction: AFC Diffractometer Control Software; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ATOMS (Dowty, 1999 ); software used to prepare material for publication: SHELXL97.

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808019508/bq2084sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536808019508/bq2084Isup2.hkl

checkCIF report

Comment top

Oxalates are of considerable interest because many of them are natural minerals and in addition, the oxalate anion can adopt different coordination modes to bind metals to form infinite chains, sheets and networks, leading to the rich structural chemistry (Lu et al., 2004; Dean et al., 2004; Audebrand et al., 2003). In the system of mixed oxalates, A_xB_y(C₂O₄)_z.nH₂O, combining alkali-metal elements (A) and alkali-earth-metal cations (B), only one compound, Cs₂Mg(C₂O₄)₂.4H₂O, has been previously found, and it has a layered structure character in which layers of MgO₄(H₂O)₂ octahedra paralel to (10–1) are separated by corrugated layers of nine-coordinated Cs atoms (Kolitsch, 2004). During our exploratory syntheses of novel hydrated borate materials, we have obtained a new member of the A_xB_y(C₂O₄)_z.nH₂O family of compounds, Na₂Mg₂(C₂O₄)₃.2H₂O. It has a one-dimensional character consisting of [Mg₂(C₂O₄)₃(H₂O)₂]_n^2n- infinite chains. We describe its synthesis and crystal structure here for the first time.

The title compound is isotypic with its Co analogue (Price et al., 2000) and the crystal structure consists of Na⁺ and Mg²⁺ cations, [C₂O₄]^2- groups, and H₂O molecules as the fundamental structural building units (Fig. 1). Mg²⁺ ions are ligated by H₂O molecules and bridged by tri-dentate oxalate ligands to generate a one-dimensional infinite polymeric chain, [Mg(C₂O₄)(H₂O)]_n. Two neighboring inversion-center-related [Mg(C₂O₄)(H₂O)]_n chains are further bridged by tetra-dentate oxalate ligands to complete the octahedral coordination sphere of Mg²⁺ and to form a ladder-like double chain with the composition [Mg₂(C₂O₄)₃(H₂O)₂]_n^2n- (Fig. 2 b). Mg···Mg distances along the double chain are 5.846 (1) Å, slightly longer than those across the chain (5.390 (1) Å). The [Mg₂(C₂O₄)₃(H₂O)₂]_n^2n- chains extend along the [100] direction and pack in two orientations in a herringbone pattern, as illustrated in Fig.2a. These chains are held together via medium-to-weak O—H···O hydrogen bonds existing between the coordinated H₂O molecules and the O atoms from tri-dentate oxalate ligands (Table 1). Na⁺ cations are located in the void space between the chains to balance charge.

There is one crystallographically independent Na⁺ cation, which is coordinated to seven O atoms, forming an irregular coordination polyhedral geometry. The Na—O distances range from 2.2952 (10) to 2.8074 (10) Å, with an average of 2.510 Å, which is comparable to the value 2.46 Å computed from crystal radii for a 7-coordinated Na⁺ ion (Shannon, 1976) and the distances 2.409 (3)–2.606 (3) Å (average 2.505 Å, CN = 7) in NaLi₂BO₃ (Miessen & Hoppe, 1987). Bond valence sum (BVS) calculations using Brown's formula (Brown & Altermatt,1985) produced a BVS value of 1.15 for Na, in good agreement with its expected formal valence. The Mg atom also occupies one crystallographically distinct site. However, each Mg²⁺ is coordinated by six O atoms, five of which are from three oxalate ions and the other from one H₂O molecule. The MgO₆ octahedron is strongly distorted, with the 180° octahedral angles being 162.33 (4)–171.66 (3)°, and the 90° octahedral angles in the range 78.40 (3)–99.05 (4)°, the smallest angle being associated with the constrained Mg1—O4ⁱ—C2ⁱ –C3ⁱ –O5ⁱ five-membered ring [Symmetry codes: (i) -1 + x, y, z]. The Mg—O distances of 2.0436 (9)–2.1429 (9) Å (average 2.078 Å) are very reasonable when compared with the ranges 2.057 (9)–2.080 (9) Å (average 2.065 Å) in Mg(NO₃)₂.6H₂O, where octahedrally coordinated Mg²⁺ is also found (Schefer & Grube, 1995). The calculated BVS value for Mg is also reasonable, at 2.12. Of the two unique oxalate ions, the C1-based oxalate sits on an inversion center and the C2/C3-based one on a general position. Both oxalate ions are nearly planar, with a mean deviation of 0.0004 and 0.1418 Å, respectively, and the bond geometries of [C₂O₄]^2- are in accord with those observed in other oxalate compounds (Lethbridge et al., 2003).

Related literature top

For related literature, see: Audebrand et al. (2003); Brown & Altermatt (1985); Dean et al. (2004); Kolitsch (2004); Lethbridge et al. (2003); Lu et al. (2004); Miessen & Hoppe (1987); Price et al. (2000); Schefer & Grube (1995); Shannon (1976).

Experimental top

The title compound was synthesized by a two-step process. First, for the preparation of the precursor, Na₃MgB₅O₁₀, a stoichiometric mixture of Na₂CO₃, MgO, and H₃BO₃ was heated at 873 K for two weeks with several intermediate re-mixings and the resulting product was identified to be the pure phase of Na₃MgB₅O₁₀ based on the powder XRD analysis. Then, a 0.300 g (0.976 mmol) sample of Na₃MgB₅O₁₀, 0.300 g (2.380 mmol) H₂(C₂O₄).2H₂O, and 3 ml H₂O were sealed in an 15-ml Teflon-lined autoclave and subsequently heated at 453 K for one week, then cooled slowly to room temperature. The product consisted of colorless, prismatic crystals with the largest having dimensions of 0.6 × 0.6 × 1.2 mm³ in colorless mother liquor. The final pH of the reaction system was about 2.0. The crystals were isolated in about 70% yield (based on Mg) by washing the reaction product with deionized water and anhydrous ethanol followed by drying with anhydrous acetone. The powder XRD pattern of the ground crystals is in good agreement with that calculated from the single-crystal data, confirming that the pure phase of the title compound has been obtained. Although boron was not incorporated into the final structure, borate anions may serve as mineralizers to enhance the crystal growth.

Computing details top

Data collection: AFC Diffractometer Control Software (Rigaku, 1994); cell refinement: AFC Diffractometer Control Software (Rigaku, 1994); data reduction: AFC Diffractometer Control Software (Rigaku, 1994); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ATOMS (Dowty, 1999); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top

	Fig. 1. The connectivity in Na₂Mg₂(C₂O₄)₃.2H₂O, shown with displacement ellipsoids at the 50% probability level. [Symmetry codes: (i) -1 + x, y, z; (iv) 1 - x, 1 - y, 1 - z]
	Fig. 2. The crystal structure of Na₂Mg₂(C₂O₄)₃.2H₂O projected along the [100] direction (a) as well as the single chain of [Mg₂(C₂O₄)₃(H₂O)₂]_n^2n- (b). H···O hydrogen bond contacts are shown as dashed lines; symmetry codes are the same as those in Figure 1.

Poly[disodium [diaquatri-µ₂-oxalato-dimagnesium(II)]] top

Crystal data top

Na₂[Mg₂(C₂O₄)₃(H₂O)₂]	F(000) = 396
M_r = 394.70	D_x = 2.070 Mg m⁻³
Monoclinic, P2₁/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 25 reflections
a = 5.8460 (12) Å	θ = 21.9–22.5°
b = 15.726 (3) Å	µ = 0.34 mm⁻¹
c = 7.0190 (14) Å	T = 290 K
β = 101.11 (3)°	Prism, colorless
V = 633.2 (2) Å³	0.4 × 0.2 × 0.2 mm
Z = 2

Data collection top

Rigaku AFC-7R diffractometer	2027 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	R_int = 0.029
Graphite monochromator	θ_max = 32.5°, θ_min = 2.6°
2θ–ω scans	h = 0→8
Absorption correction: ψ scan (Kopfmann & Huber, 1968)	k = 0→23
T_min = 0.912, T_max = 0.943	l = −10→10
2457 measured reflections	3 standard reflections every 150 reflections
2280 independent reflections	intensity decay: 1.2%

Refinement top

Refinement on F²	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: difference Fourier map
R[F² > 2σ(F²)] = 0.033	All H-atom parameters refined
wR(F²) = 0.095	w = 1/[σ²(F_o²) + (0.0581P)² + 0.0731P] where P = (F_o² + 2F_c²)/3
S = 1.11	(Δ/σ)_max = 0.001
2280 reflections	Δρ_max = 0.54 e Å⁻³
118 parameters	Δρ_min = −0.56 e Å⁻³
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.310 (14)

Crystal data top

Na₂[Mg₂(C₂O₄)₃(H₂O)₂]	V = 633.2 (2) Å³
M_r = 394.70	Z = 2
Monoclinic, P2₁/c	Mo Kα radiation
a = 5.8460 (12) Å	µ = 0.34 mm⁻¹
b = 15.726 (3) Å	T = 290 K
c = 7.0190 (14) Å	0.4 × 0.2 × 0.2 mm
β = 101.11 (3)°

Data collection top

Rigaku AFC-7R diffractometer	2027 reflections with I > 2σ(I)
Absorption correction: ψ scan (Kopfmann & Huber, 1968)	R_int = 0.029
T_min = 0.912, T_max = 0.943	3 standard reflections every 150 reflections
2457 measured reflections	intensity decay: 1.2%
2280 independent reflections

Refinement top

R[F² > 2σ(F²)] = 0.033	0 restraints
wR(F²) = 0.095	All H-atom parameters refined
S = 1.11	Δρ_max = 0.54 e Å⁻³
2280 reflections	Δρ_min = −0.56 e Å⁻³
118 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
Na1	0.46789 (7)	0.81852 (3)	0.30526 (7)	0.01952 (13)
Mg1	0.27308 (6)	0.60144 (2)	0.21580 (5)	0.01297 (12)
C1	0.49584 (17)	0.46394 (6)	0.42523 (14)	0.01492 (18)
O1	0.38596 (15)	0.47765 (5)	0.25634 (11)	0.01885 (17)
O2	0.60143 (15)	0.39673 (5)	0.48571 (11)	0.02059 (18)
C2	0.79984 (15)	0.64930 (6)	0.21459 (13)	0.01346 (18)
O3	0.58217 (13)	0.65770 (5)	0.17720 (13)	0.02067 (17)
O4	0.91349 (13)	0.58130 (5)	0.22737 (12)	0.01867 (17)
C3	0.94672 (16)	0.73184 (6)	0.24642 (14)	0.01425 (18)
O5	1.15751 (12)	0.72335 (5)	0.23254 (12)	0.01735 (17)
O6	0.85117 (14)	0.79871 (5)	0.28409 (15)	0.0255 (2)
O7	0.18307 (14)	0.58554 (5)	−0.08136 (12)	0.01742 (16)
H7A	0.174 (4)	0.5388 (16)	−0.124 (4)	0.058 (7)*
H7B	0.065 (5)	0.6120 (18)	−0.141 (4)	0.077 (9)*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Na1	0.0152 (2)	0.0208 (2)	0.0230 (2)	−0.00005 (15)	0.00461 (16)	0.00233 (16)
Mg1	0.01111 (17)	0.01020 (17)	0.01744 (18)	0.00096 (10)	0.00233 (12)	0.00035 (10)
C1	0.0171 (4)	0.0111 (4)	0.0166 (4)	0.0015 (3)	0.0031 (3)	−0.0012 (3)
O1	0.0258 (4)	0.0130 (3)	0.0161 (3)	0.0031 (3)	−0.0001 (3)	−0.0011 (2)
O2	0.0289 (4)	0.0134 (3)	0.0179 (3)	0.0080 (3)	0.0005 (3)	−0.0014 (2)
C2	0.0104 (4)	0.0140 (4)	0.0165 (4)	−0.0015 (3)	0.0039 (3)	−0.0008 (3)
O3	0.0100 (3)	0.0223 (4)	0.0300 (4)	−0.0018 (3)	0.0045 (3)	0.0009 (3)
O4	0.0147 (3)	0.0120 (3)	0.0297 (4)	−0.0007 (2)	0.0054 (3)	−0.0008 (3)
C3	0.0105 (4)	0.0120 (4)	0.0200 (4)	0.0002 (3)	0.0022 (3)	−0.0009 (3)
O5	0.0102 (3)	0.0113 (3)	0.0310 (4)	0.0000 (2)	0.0051 (3)	−0.0008 (3)
O6	0.0150 (3)	0.0144 (3)	0.0470 (5)	0.0026 (3)	0.0062 (3)	−0.0083 (3)
O7	0.0176 (3)	0.0148 (3)	0.0191 (3)	0.0019 (3)	0.0017 (3)	−0.0011 (2)

Geometric parameters (Å, º) top

Na1—O6	2.2952 (10)	Mg1—O4ⁱ	2.1429 (9)
Na1—O5ⁱ	2.3315 (9)	C1—O1	1.2533 (12)
Na1—O2ⁱⁱ	2.3514 (10)	C1—O2	1.2559 (11)
Na1—O7ⁱⁱⁱ	2.4886 (10)	C1—C1^iv	1.5399 (19)
Na1—O3ⁱⁱⁱ	2.5941 (12)	C2—O4	1.2531 (12)
Na1—O1ⁱⁱ	2.7059 (10)	C2—O3	1.2557 (11)
Na1—O3	2.8074 (10)	C2—C3	1.5485 (13)
Mg1—O5ⁱ	2.0436 (9)	C3—O6	1.2428 (12)
Mg1—O1	2.058 (1)	C3—O5	1.2618 (11)
Mg1—O7	2.0656 (10)	O7—H7A	0.79 (3)
Mg1—O3	2.0761 (9)	O7—H7B	0.85 (3)
Mg1—O2^iv	2.0823 (10)

O6—Na1—O5ⁱ	128.83 (4)	O5ⁱ—Mg1—O2^iv	89.17 (3)
O6—Na1—O2ⁱⁱ	91.25 (4)	O1—Mg1—O2^iv	80.36 (3)
O5ⁱ—Na1—O2ⁱⁱ	98.57 (4)	O7—Mg1—O2^iv	171.66 (3)
O6—Na1—O7ⁱⁱⁱ	145.56 (3)	O3—Mg1—O2^iv	88.78 (5)
O5ⁱ—Na1—O7ⁱⁱⁱ	85.34 (3)	O5ⁱ—Mg1—O4ⁱ	78.40 (3)
O2ⁱⁱ—Na1—O7ⁱⁱⁱ	86.94 (4)	O1—Mg1—O4ⁱ	98.38 (4)
O6—Na1—O3ⁱⁱⁱ	91.11 (4)	O7—Mg1—O4ⁱ	87.68 (5)
O5ⁱ—Na1—O3ⁱⁱⁱ	110.58 (4)	O3—Mg1—O4ⁱ	162.33 (4)
O2ⁱⁱ—Na1—O3ⁱⁱⁱ	140.04 (3)	O2^iv—Mg1—O4ⁱ	97.00 (5)
O7ⁱⁱⁱ—Na1—O3ⁱⁱⁱ	69.46 (3)	O1—C1—O2	126.40 (9)
O6—Na1—O1ⁱⁱ	76.88 (3)	O1—C1—C1^iv	117.46 (10)
O5ⁱ—Na1—O1ⁱⁱ	144.59 (3)	O2—C1—C1^iv	116.14 (11)
O2ⁱⁱ—Na1—O1ⁱⁱ	52.00 (3)	C1—O1—Mg1	112.70 (6)
O7ⁱⁱⁱ—Na1—O1ⁱⁱ	75.03 (3)	C1—O2—Mg1^iv	112.55 (6)
O3ⁱⁱⁱ—Na1—O1ⁱⁱ	89.97 (3)	O4—C2—O3	127.35 (9)
O6—Na1—O3	63.99 (3)	O4—C2—C3	115.69 (8)
O5ⁱ—Na1—O3	64.84 (3)	O3—C2—C3	116.96 (8)
O2ⁱⁱ—Na1—O3	101.83 (3)	C2—O3—Mg1	143.16 (7)
O7ⁱⁱⁱ—Na1—O3	149.74 (3)	C2—O4—Mg1^v	112.43 (6)
O3ⁱⁱⁱ—Na1—O3	114.90 (3)	O6—C3—O5	126.27 (9)
O1ⁱⁱ—Na1—O3	132.84 (3)	O6—C3—C2	118.71 (8)
O5ⁱ—Mg1—O1	168.63 (4)	O5—C3—C2	115.01 (8)
O5ⁱ—Mg1—O7	98.56 (4)	C3—O5—Mg1^v	116.25 (6)
O1—Mg1—O7	92.16 (3)	Mg1—O7—H7A	118.6 (19)
O5ⁱ—Mg1—O3	85.03 (3)	Mg1—O7—H7B	117.6 (19)
O1—Mg1—O3	99.05 (4)	H7A—O7—H7B	106 (2)
O7—Mg1—O3	88.77 (4)

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

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O7—H7a···O4^vi	0.78 (3)	2.06 (3)	2.8335 (13)	170 (2)
O7—H7b···O6^vii	0.84 (3)	1.89 (3)	2.6952 (13)	162 (3)

Symmetry codes: (vi) −x+1, −y+1, −z; (vii) x−1, −y+3/2, z−1/2.

Experimental details

Crystal data
Chemical formula	Na₂[Mg₂(C₂O₄)₃(H₂O)₂]
M_r	394.70
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	290
a, b, c (Å)	5.8460 (12), 15.726 (3), 7.0190 (14)
β (°)	101.11 (3)
V (Å³)	633.2 (2)
Z	2
Radiation type	Mo Kα
µ (mm⁻¹)	0.34
Crystal size (mm)	0.4 × 0.2 × 0.2

Data collection
Diffractometer	Rigaku AFC-7R diffractometer
Absorption correction	ψ scan (Kopfmann & Huber, 1968)
T_min, T_max	0.912, 0.943
No. of measured, independent and observed [I > 2σ(I)] reflections	2457, 2280, 2027
R_int	0.029
(sin θ/λ)_max (Å⁻¹)	0.755

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.033, 0.095, 1.11
No. of reflections	2280
No. of parameters	118
H-atom treatment	All H-atom parameters refined
Δρ_max, Δρ_min (e Å⁻³)	0.54, −0.56

Computer programs: AFC Diffractometer Control Software (Rigaku, 1994), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ATOMS (Dowty, 1999).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O7—H7a···O4ⁱ	0.78 (3)	2.06 (3)	2.8335 (13)	170 (2)
O7—H7b···O6ⁱⁱ	0.84 (3)	1.89 (3)	2.6952 (13)	162 (3)

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

Acknowledgements

This work was supported by the Funding Project for Academic Human Resources Development in Institutions of Higher Learning under the Jurisdiction of Beijing Municipality.

References

Audebrand, N., Raite, S. & Louer, D. (2003). Solid State Sci. 5, 783–794. Web of Science CSD CrossRef CAS Google Scholar
Brown, I. D. & Altermatt, D. (1985). Acta Cryst. B41, 244–247. CrossRef CAS Web of Science IUCr Journals Google Scholar
Dean, P. A. W., Craig, D., Dance, I., Russell, V. & Scudder, M. (2004). Inorg. Chem. 43, 443–449. Web of Science CSD CrossRef PubMed CAS Google Scholar
Dowty, E. (1999). ATOMS. Shape Software, Tennessee, USA. Google Scholar
Kolitsch, U. (2004). Acta Cryst. C60, m129–m133. Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
Kopfmann, G. & Huber, R. (1968). Acta Cryst. A24, 348–351. CrossRef IUCr Journals Web of Science Google Scholar
Lethbridge, Z. A. D., Congreve, A. F., Esslemont, E., Slawin, A. M. Z. & Lightfoot, P. (2003). J. Solid State Chem. 172, 212–218. Web of Science CSD CrossRef CAS Google Scholar
Lu, J., Li, Y., Zhao, K., Xu, J.-Q., Yu, J.-H., Li, G.-H., Zhang, X., Bie, H.-Y. & Wang, T.-G. (2004). Inorg. Chem. Commun. 7, 1154–1156. Web of Science CSD CrossRef CAS Google Scholar
Miessen, M. & Hoppe, R. (1987). Z. Anorg. Allg. Chem. 545, 157–168. CrossRef CAS Web of Science Google Scholar
Price, D. J., Powell, A. K. & Wood, P. T. (2000). J. Chem. Soc. Dalton Trans. pp. 3566–3569. Web of Science CrossRef Google Scholar
Rigaku (1994). AFC Diffractometer Control Software. Rigaku Corporation, Tokyo, Japan. Google Scholar
Schefer, J. & Grube, M. (1995). Mater. Res. Bull. 30, 1235–1241. CrossRef Web of Science Google Scholar
Shannon, R. D. (1976). Acta Cryst. A32, 751–767. CrossRef CAS IUCr Journals Web of Science Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar