[Al(H2O)6][Cr(OH)6Mo6O18]·10H2O

Li, B.; Ye, L.; Wu, L.-X.

doi:10.1107/S1600536810053936

inorganic compounds

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Volume 67| Part 2| February 2011| Page i8

doi:10.1107/S1600536810053936

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[Al(H₂O)₆][Cr(OH)₆Mo₆O₁₈]·10H₂O

Bao Li,^a Ling Ye ^a and Li-Xin Wu ^a ^*

^aState Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun 130012, People's Republic of China
^*Correspondence e-mail: wulx@jlu.edu.cn

(Received 29 November 2010; accepted 23 December 2010; online 12 January 2011)

The title compound, [Al(H₂O)₆][Cr(OH)₆Mo₆O₁₈]·10H₂O, hexaaquaaluminium hexahydroxidooctadecaoxidomolybdochromate(III) decahydrate, crystallizes isotypically with its gallium analogue [Ga(H₂O)₆][Cr(OH)₆Mo₆O₁₈].10H₂O. In the structure of the title compound, both the [Al(H₂O)₆]³⁺ cation and the Anderson-type [Cr(OH)₆Mo₆O₁₈]³⁻ anion lie on centres of inversion. The anion is composed of seven edge-sharing octahedra, six of which are MoO₆ octahedra that are arranged hexagonally around the central Cr(OH)₆ octahedron. The anions are linked to each other by O—H⋯O hydrogen bonds into infinite chains along [100]. These chains are further connected with the [Al(H₂O)₆]³⁺ cations through O—H⋯O hydrogen bonds into sheets parallel to (01 $[\overline{1}]$ ). O—H⋯O hydrogen bonds involving all the lattice water molecules finally link the sheets into a three-dimensional network.

Related literature

For background literature on polyoxometalates, see: An et al. (2005 ); Shivaiah et al. (2003 ). The isotypic gallium analogue was reported by Kaziev et al. (2002 ).

Experimental

Crystal data

[Al(H₂O)₆][Cr(OH)₆Mo₆O₁₈]·10H₂O
M_r = 1332.92
Triclinic, $[P \overline 1]$
a = 6.809 (5) Å
b = 11.267 (7) Å
c = 11.596 (9) Å
α = 101.26 (3)°
β = 97.02 (3)°
γ = 101.81 (3)°
V = 841.7 (10) Å³
Z = 1
Mo Kα radiation
μ = 2.63 mm⁻¹
T = 290 K
0.12 × 0.12 × 0.11 mm

Data collection

Rigaku R-AXIS RAPID diffractometer
Absorption correction: multi-scan (ABSCOR; Higashi, 1995 ) T_min = 0.745, T_max = 0.770
8257 measured reflections
3801 independent reflections
3346 reflections with I > 2σ(I)
R_int = 0.037

Refinement

R[F² > 2σ(F²)] = 0.033
wR(F²) = 0.093
S = 1.10
3801 reflections
217 parameters
24 restraints
H-atom parameters constrained
Δρ_max = 0.89 e Å⁻³
Δρ_min = −0.86 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
OH3—H3⋯OT1ⁱ	0.85	1.85	2.681 (4)	167
OH1—H1⋯OB2ⁱ	0.85	2.10	2.944 (4)	172
OH2—H2⋯OW5ⁱⁱ	0.85	1.82	2.665 (5)	178
OW3—H8⋯OT4ⁱⁱⁱ	0.85	1.83	2.628 (5)	156
OW3—H9⋯OW7ⁱⁱⁱ	0.85	1.81	2.632 (5)	163
OW1—H4⋯OW7	0.85	2.01	2.730 (5)	142
OW1—H5⋯OW4^iv	0.85	1.74	2.577 (5)	167
OW2—H6⋯OB3^v	0.85	1.72	2.559 (4)	171
OW2—H7⋯OW6	0.85	1.88	2.728 (5)	178
OW4—H10⋯OB1^vi	0.85	1.94	2.737 (5)	156
OW5—H12⋯OT1^vii	0.86	2.15	3.002 (6)	179
OW5—H13⋯OW6^viii	0.85	1.99	2.842 (6)	180
OW6—H14⋯OW5^v	0.85	2.04	2.800 (6)	149
OW6—H15⋯OT3ⁱⁱⁱ	0.85	2.45	3.091 (6)	133
OW7—H16⋯OT3ⁱⁱⁱ	0.85	2.13	2.878 (5)	146
OW7—H17⋯OW8	0.85	1.98	2.759 (5)	152
OW8—H18⋯OT1^ix	0.85	2.19	2.902 (5)	141
OW8—H18⋯OT6^x	0.85	2.62	3.241 (5)	131
OW8—H19⋯OW8^xi	0.85	2.56	3.283 (6)	144
Symmetry codes: (i) -x+1, -y, -z; (ii) -x, -y+1, -z; (iii) -x+1, -y+1, -z+1; (iv) x-1, y, z; (v) -x, -y+1, -z+1; (vi) x+1, y, z+1; (vii) -x+1, -y+1, -z; (viii) x, y, z-1; (ix) x, y, z+1; (x) -x, -y, -z+1; (xi) -x+1, -y, -z+1.

Data collection: RAPID-AUTO (Rigaku, 1998 ); cell refinement: RAPID-AUTO; data reduction: CrystalStructure (Rigaku/MSC, 2002 ); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: PLATON (Spek, 2009 ); software used to prepare material for publication: SHELXL97.

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536810053936/wm2434sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536810053936/wm2434Isup2.hkl

checkCIF report

Comment top

Anderson-type polyoxometalate (POM) anions are frequently used as building blocks to construct extended solid frameworks (An et al., 2005; Shivaiah et al., 2003). As a part of our ongoing study on POMs, we report here the crystal structure of the title compound, [Al(H₂O)₆][Cr(OH)₆Mo₆O₁₈].10H₂O.

The crystal structure of the title compound (Fig. 1) consists of [Al(H₂O)₆]³⁺ cations and Anderson-type [Cr(OH)₆Mo₆O₁₈]^3- anions, both with 1 symmetry. The [Cr(OH)₆] octahedron lies on the center of six surrounding [MoO₆] octahedra, all linked through common edges. According to different coordination environments, there are three kinds of O atoms in the anion. The first involves twelve terminal O atoms (labelled OTx) that only bind to one Mo atom with distances ranging from 1.691 (4) Å to 1.721 (3) Å. The second type involves six bridging O atoms (OBx) shared by two Mo atoms with distances ranging from 1.927 (3) Å to 1.951 (3) Å. The third type involves six O atoms (OHx) located between the Mo and Cr atoms with Mo—OH bond lengths ranging from 2.252 (3) Å to 2.314 (3) Å. All these bond lenghths and corresponding angles are in the normal ranges (An et al., 2005).

Abundant hydrogen bonding exist in the title structure (Table 1). The OH groups of the POM anion are involved in forming O—H···O hydrogen bonds to adjacent anions and link the [Cr(OH)₆Mo₆O₁₈]^3- anions into infinite chains along [100]. The chains are further connected with [Al(H₂O)₆]³⁺ octahedra through O—H···O hydrogen bonds into sheets lying parallel to (011). The O—H···O hydrogen bonds involving all the lattice water molecules finally link the sheets into a three-dimensional network (Fig. 2).

It should be noted that the title compound is isotypic with its gallium analogue [Ga(H₂O)₆][Cr(OH)₆Mo₆O₁₈].10H₂O described several years ago (Kaziev, et al. 2002). In the latter structure, the Cr³⁺ and Ga³⁺ sites show occupational disorder due to their very similar ionic radius, while such a disorder is not observed in the title compound.

Related literature top

For background literature on polyoxometalates, see: An et al. (2005); Shivaiah et al. (2003). The isotypic gallium analogue was reported by Kaziev et al. (2002).

Experimental top

CrCl₃.6H₂O (0.532 g, 2 mmol) and Na₂MoO₄.2H₂O (3.629 g, 15 mmol) were dissolved in water (30 ml); ice acetic acid was dropped into the solution until it became clear. The resultant solution was heated for 1 h under stirring and AlCl₃ (0.267 g, 2 mmol) was added subsequently. The mixture was heated for half an hour and cooled to room temperature. Colorless single crystals were obtained three weeks later after partial evaporation of water.

Computing details top

Data collection: RAPID-AUTO (Rigaku, 1998); cell refinement: RAPID-AUTO (Rigaku, 1998); data reduction: CrystalStructure (Rigaku/MSC, 2002); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: PLATON (Spek, 2009); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top

	Fig. 1. The [Al(H₂O)₆]³⁺ cation and the Anderson-type anion as well as the five independent lattice water molecules of the title compound, showing the atom-labelling scheme. Displacement ellipsoids are drawn at the 30% probability level. H atoms have been omitted for clarity. [Symmetry codes: (A) -x, 1 - y, 1 - z; (B)-x, -y, -z.]
	Fig. 2. Crystal packing diagram of the title compound, showing the three-dimensional network between the molecular entities through hydrogen bonding (dashed lines).

hexaaquaaluminium hexahydroxidooctadecaoxidomolybdochromate(III) decahydrate, top

Crystal data top

[Al(H₂O)₆][Cr(OH)₆Mo₆O₁₈]·10H₂O	Z = 1
M_r = 1332.92	F(000) = 647
Triclinic, P1	D_x = 2.630 Mg m⁻³
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 6.809 (5) Å	Cell parameters from 7543 reflections
b = 11.267 (7) Å	θ = 3.2–27.1°
c = 11.596 (9) Å	µ = 2.63 mm⁻¹
α = 101.26 (3)°	T = 290 K
β = 97.02 (3)°	Block, colorless
γ = 101.81 (3)°	0.12 × 0.12 × 0.11 mm
V = 841.7 (10) Å³

Data collection top

Rigaku R-AXIS RAPID diffractometer	3801 independent reflections
Radiation source: fine-focus sealed tube	3346 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.037
ω scans	θ_max = 27.5°, θ_min = 3.2°
Absorption correction: multi-scan (ABSCOR; Higashi, 1995)	h = −7→8
T_min = 0.745, T_max = 0.770	k = −14→14
8257 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)] = 0.033	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.093	H-atom parameters constrained
S = 1.10	w = 1/[σ²(F_o²) + (0.0331P)² + 2.719P] where P = (F_o² + 2F_c²)/3
3801 reflections	(Δ/σ)_max = 0.009
217 parameters	Δρ_max = 0.89 e Å⁻³
24 restraints	Δρ_min = −0.86 e Å⁻³

Crystal data top

[Al(H₂O)₆][Cr(OH)₆Mo₆O₁₈]·10H₂O	γ = 101.81 (3)°
M_r = 1332.92	V = 841.7 (10) Å³
Triclinic, P1	Z = 1
a = 6.809 (5) Å	Mo Kα radiation
b = 11.267 (7) Å	µ = 2.63 mm⁻¹
c = 11.596 (9) Å	T = 290 K
α = 101.26 (3)°	0.12 × 0.12 × 0.11 mm
β = 97.02 (3)°

Data collection top

Rigaku R-AXIS RAPID diffractometer	3801 independent reflections
Absorption correction: multi-scan (ABSCOR; Higashi, 1995)	3346 reflections with I > 2σ(I)
T_min = 0.745, T_max = 0.770	R_int = 0.037
8257 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.033	24 restraints
wR(F²) = 0.093	H-atom parameters constrained
S = 1.10	Δρ_max = 0.89 e Å⁻³
3801 reflections	Δρ_min = −0.86 e Å⁻³
217 parameters

Special details top

Experimental. (See detailed section in the paper)

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
Al1	0.0000	0.5000	0.5000	0.0162 (4)
Cr1	0.0000	0.0000	0.0000	0.01424 (19)
Mo1	0.37029 (5)	0.16663 (3)	−0.10502 (3)	0.01629 (11)
Mo2	0.33617 (6)	0.24360 (3)	0.17992 (3)	0.01870 (11)
Mo3	−0.02648 (6)	0.07285 (3)	0.29050 (3)	0.01802 (11)
OH1	0.2099 (4)	−0.0332 (3)	−0.0983 (3)	0.0156 (6)
H1	0.2955	−0.0782	−0.0941	0.023*
OB1	0.1450 (5)	0.1055 (3)	−0.2357 (3)	0.0203 (6)
OT1	0.5602 (5)	0.1125 (3)	−0.1683 (3)	0.0251 (7)
OT2	0.4158 (5)	0.3199 (3)	−0.1095 (3)	0.0287 (8)
OH2	0.1174 (4)	0.1756 (3)	0.0024 (3)	0.0159 (6)
H2	0.0530	0.2258	−0.0217	0.024*
OB2	0.4843 (5)	0.1784 (3)	0.0594 (3)	0.0209 (6)
OT3	0.3656 (6)	0.3945 (3)	0.1671 (3)	0.0321 (8)
OT4	0.5053 (6)	0.2483 (4)	0.3027 (3)	0.0365 (9)
OB3	0.0878 (5)	0.2295 (3)	0.2494 (3)	0.0202 (6)
OH3	0.1830 (5)	0.0372 (3)	0.1527 (3)	0.0166 (6)
H3	0.2705	−0.0068	0.1480	0.025*
OT5	0.1586 (6)	0.0662 (3)	0.3999 (3)	0.0315 (8)
OT6	−0.2117 (6)	0.1163 (4)	0.3617 (3)	0.0334 (8)
OW1	0.1050 (5)	0.3690 (3)	0.5388 (3)	0.0242 (7)
H4	0.2073	0.3992	0.5942	0.036*
H5	0.0411	0.3152	0.5715	0.036*
OW2	0.0105 (5)	0.5686 (3)	0.6627 (3)	0.0234 (7)
H6	−0.0143	0.6394	0.6869	0.035*
H7	0.0689	0.5534	0.7255	0.035*
OW3	0.2655 (5)	0.5935 (3)	0.5085 (3)	0.0254 (7)
H8	0.3070	0.6445	0.5758	0.038*
H9	0.3240	0.6029	0.4491	0.038*
OW4	0.9017 (6)	0.2342 (3)	0.6599 (4)	0.0379 (9)
H10	0.9862	0.2141	0.7084	0.057*
H11	0.8043	0.2487	0.6955	0.057*
OW5	0.0885 (6)	0.6667 (3)	0.0685 (4)	0.0361 (9)
H12	0.1879	0.7302	0.0967	0.054*
H13	0.1180	0.6225	0.0079	0.054*
OW6	0.1882 (6)	0.5186 (4)	0.8662 (4)	0.0378 (9)
H14	0.1337	0.4753	0.9112	0.057*
H15	0.3078	0.5567	0.9018	0.057*
OW7	0.4894 (4)	0.3814 (3)	0.6484 (3)	0.0359 (9)
H16	0.5251	0.4239	0.7199	0.054*
H17	0.4701	0.3052	0.6506	0.054*
OW8	0.4860 (4)	0.1318 (3)	0.5850 (3)	0.0407 (9)
H18	0.4573	0.0970	0.6416	0.061*
H19	0.5475	0.0869	0.5416	0.061*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Al1	0.0168 (9)	0.0139 (8)	0.0166 (9)	0.0037 (6)	0.0007 (7)	0.0011 (7)
Cr1	0.0137 (5)	0.0128 (4)	0.0148 (4)	0.0034 (3)	0.0000 (4)	0.0008 (3)
Mo1	0.01433 (19)	0.01556 (18)	0.0194 (2)	0.00386 (13)	0.00296 (14)	0.00448 (14)
Mo2	0.0168 (2)	0.01554 (18)	0.0188 (2)	0.00120 (13)	−0.00073 (14)	−0.00287 (14)
Mo3	0.0201 (2)	0.01879 (19)	0.01451 (19)	0.00612 (14)	0.00132 (14)	0.00159 (14)
OH1	0.0144 (14)	0.0151 (13)	0.0187 (15)	0.0084 (11)	0.0020 (12)	0.0026 (11)
OB1	0.0223 (16)	0.0205 (14)	0.0188 (16)	0.0051 (12)	0.0015 (13)	0.0073 (12)
OT1	0.0228 (17)	0.0310 (17)	0.0256 (18)	0.0124 (13)	0.0065 (14)	0.0086 (14)
OT2	0.0266 (19)	0.0228 (16)	0.037 (2)	0.0030 (13)	0.0062 (15)	0.0107 (15)
OH2	0.0146 (14)	0.0126 (13)	0.0205 (15)	0.0038 (11)	0.0020 (12)	0.0040 (11)
OB2	0.0183 (16)	0.0221 (15)	0.0199 (16)	0.0041 (12)	0.0001 (13)	0.0017 (12)
OT3	0.036 (2)	0.0178 (15)	0.038 (2)	0.0020 (14)	0.0096 (17)	−0.0011 (14)
OT4	0.030 (2)	0.043 (2)	0.0262 (19)	0.0073 (16)	−0.0073 (16)	−0.0069 (16)
OB3	0.0233 (17)	0.0163 (14)	0.0188 (15)	0.0053 (12)	0.0018 (13)	−0.0007 (12)
OH3	0.0175 (15)	0.0166 (13)	0.0149 (14)	0.0069 (11)	−0.0005 (12)	0.0005 (11)
OT5	0.030 (2)	0.0379 (19)	0.0242 (18)	0.0091 (15)	−0.0051 (15)	0.0070 (15)
OT6	0.036 (2)	0.038 (2)	0.032 (2)	0.0184 (16)	0.0136 (17)	0.0051 (16)
OW1	0.0248 (18)	0.0189 (14)	0.0286 (18)	0.0078 (13)	−0.0001 (14)	0.0047 (13)
OW2	0.0310 (19)	0.0222 (15)	0.0169 (15)	0.0106 (13)	0.0017 (13)	0.0008 (12)
OW3	0.0215 (17)	0.0267 (16)	0.0216 (16)	−0.0024 (13)	0.0032 (13)	−0.0013 (13)
OW4	0.034 (2)	0.0346 (19)	0.050 (2)	0.0118 (16)	−0.0007 (18)	0.0218 (18)
OW5	0.035 (2)	0.0285 (18)	0.044 (2)	0.0106 (15)	0.0019 (18)	0.0068 (16)
OW6	0.036 (2)	0.044 (2)	0.039 (2)	0.0160 (17)	0.0056 (18)	0.0174 (18)
OW7	0.030 (2)	0.048 (2)	0.030 (2)	0.0101 (17)	0.0063 (16)	0.0080 (17)
OW8	0.036 (2)	0.048 (2)	0.035 (2)	0.0049 (18)	−0.0012 (18)	0.0113 (18)

Geometric parameters (Å, º) top

Al1—OW1ⁱ	1.872 (3)	Mo3—OB1ⁱⁱ	1.951 (3)
Al1—OW1	1.872 (3)	Mo3—OB3	1.951 (3)
Al1—OW3ⁱ	1.877 (3)	Mo3—OH3	2.300 (3)
Al1—OW3	1.877 (3)	Mo3—OH1ⁱⁱ	2.330 (3)
Al1—OW2	1.881 (3)	OH1—Mo3ⁱⁱ	2.330 (3)
Al1—OW2ⁱ	1.881 (3)	OH1—H1	0.8500
Cr1—OH3ⁱⁱ	1.954 (3)	OB1—Mo3ⁱⁱ	1.951 (3)
Cr1—OH3	1.954 (3)	OH2—H2	0.8499
Cr1—OH2	1.970 (3)	OH3—H3	0.8501
Cr1—OH2ⁱⁱ	1.970 (3)	OW1—H4	0.8500
Cr1—OH1ⁱⁱ	1.983 (3)	OW1—H5	0.8500
Cr1—OH1	1.983 (3)	OW2—H6	0.8501
Mo1—OT2	1.703 (3)	OW2—H7	0.8499
Mo1—OT1	1.721 (3)	OW3—H8	0.8500
Mo1—OB1	1.927 (3)	OW3—H9	0.8500
Mo1—OB2	1.937 (4)	OW4—H10	0.8500
Mo1—OH2	2.252 (3)	OW4—H11	0.8500
Mo1—OH1	2.314 (3)	OW5—H12	0.8559
Mo2—OT4	1.703 (4)	OW5—H13	0.8496
Mo2—OT3	1.709 (4)	OW6—H14	0.8500
Mo2—OB2	1.939 (3)	OW6—H15	0.8500
Mo2—OB3	1.951 (3)	OW7—H16	0.8509
Mo2—OH2	2.283 (3)	OW7—H17	0.8480
Mo2—OH3	2.288 (3)	OW8—H18	0.8499
Mo3—OT6	1.691 (4)	OW8—H19	0.8500
Mo3—OT5	1.699 (4)

OW1ⁱ—Al1—OW1	180.000 (1)	OT4—Mo2—OH3	94.98 (16)
OW1ⁱ—Al1—OW3ⁱ	89.98 (16)	OT3—Mo2—OH3	158.26 (16)
OW1—Al1—OW3ⁱ	90.02 (16)	OB2—Mo2—OH3	82.20 (13)
OW1ⁱ—Al1—OW3	90.02 (16)	OB3—Mo2—OH3	71.27 (12)
OW1—Al1—OW3	89.98 (16)	OH2—Mo2—OH3	69.73 (11)
OW3ⁱ—Al1—OW3	180.0 (2)	OT6—Mo3—OT5	105.4 (2)
OW1ⁱ—Al1—OW2	89.59 (15)	OT6—Mo3—OB1ⁱⁱ	99.75 (17)
OW1—Al1—OW2	90.41 (15)	OT5—Mo3—OB1ⁱⁱ	97.91 (16)
OW3ⁱ—Al1—OW2	90.13 (15)	OT6—Mo3—OB3	99.14 (17)
OW3—Al1—OW2	89.87 (15)	OT5—Mo3—OB3	102.04 (17)
OW1ⁱ—Al1—OW2ⁱ	90.41 (15)	OB1ⁱⁱ—Mo3—OB3	147.66 (13)
OW1—Al1—OW2ⁱ	89.59 (15)	OT6—Mo3—OH3	163.68 (15)
OW3ⁱ—Al1—OW2ⁱ	89.87 (15)	OT5—Mo3—OH3	89.62 (16)
OW3—Al1—OW2ⁱ	90.13 (15)	OB1ⁱⁱ—Mo3—OH3	84.03 (12)
OW2—Al1—OW2ⁱ	180.000 (1)	OB3—Mo3—OH3	71.00 (12)
OH3ⁱⁱ—Cr1—OH3	180.00 (18)	OT6—Mo3—OH1ⁱⁱ	95.90 (16)
OH3ⁱⁱ—Cr1—OH2	96.53 (13)	OT5—Mo3—OH1ⁱⁱ	157.46 (14)
OH3—Cr1—OH2	83.47 (13)	OB1ⁱⁱ—Mo3—OH1ⁱⁱ	70.90 (12)
OH3ⁱⁱ—Cr1—OH2ⁱⁱ	83.47 (13)	OB3—Mo3—OH1ⁱⁱ	81.26 (13)
OH3—Cr1—OH2ⁱⁱ	96.53 (13)	OH3—Mo3—OH1ⁱⁱ	70.18 (12)
OH2—Cr1—OH2ⁱⁱ	180.00 (18)	Cr1—OH1—Mo1	101.22 (12)
OH3ⁱⁱ—Cr1—OH1ⁱⁱ	94.97 (14)	Cr1—OH1—Mo3ⁱⁱ	101.37 (13)
OH3—Cr1—OH1ⁱⁱ	85.03 (14)	Mo1—OH1—Mo3ⁱⁱ	92.79 (11)
OH2—Cr1—OH1ⁱⁱ	95.90 (12)	Cr1—OH1—H1	131.8
OH2ⁱⁱ—Cr1—OH1ⁱⁱ	84.10 (12)	Mo1—OH1—H1	110.7
OH3ⁱⁱ—Cr1—OH1	85.03 (14)	Mo3ⁱⁱ—OH1—H1	111.9
OH3—Cr1—OH1	94.97 (14)	Mo1—OB1—Mo3ⁱⁱ	120.22 (16)
OH2—Cr1—OH1	84.10 (12)	Cr1—OH2—Mo1	103.79 (12)
OH2ⁱⁱ—Cr1—OH1	95.90 (12)	Cr1—OH2—Mo2	103.22 (13)
OH1ⁱⁱ—Cr1—OH1	180.00 (15)	Mo1—OH2—Mo2	93.30 (12)
OT2—Mo1—OT1	104.94 (17)	Cr1—OH2—H2	125.8
OT2—Mo1—OB1	97.87 (16)	Mo1—OH2—H2	106.7
OT1—Mo1—OB1	101.08 (16)	Mo2—OH2—H2	118.4
OT2—Mo1—OB2	100.85 (16)	Mo1—OB2—Mo2	116.61 (16)
OT1—Mo1—OB2	96.87 (16)	Mo2—OB3—Mo3	118.42 (15)
OB1—Mo1—OB2	149.69 (14)	Cr1—OH3—Mo2	103.55 (13)
OT2—Mo1—OH2	94.45 (14)	Cr1—OH3—Mo3	103.34 (14)
OT1—Mo1—OH2	159.55 (14)	Mo2—OH3—Mo3	93.88 (11)
OB1—Mo1—OH2	82.26 (14)	Cr1—OH3—H3	110.0
OB2—Mo1—OH2	72.74 (13)	Mo2—OH3—H3	110.7
OT2—Mo1—OH1	162.67 (14)	Mo3—OH3—H3	131.6
OT1—Mo1—OH1	90.85 (14)	Al1—OW1—H4	108.5
OB1—Mo1—OH1	71.64 (12)	Al1—OW1—H5	122.9
OB2—Mo1—OH1	83.95 (13)	H4—OW1—H5	97.7
OH2—Mo1—OH1	70.89 (11)	Al1—OW2—H6	122.0
OT4—Mo2—OT3	105.5 (2)	Al1—OW2—H7	131.7
OT4—Mo2—OB2	98.10 (17)	H6—OW2—H7	103.9
OT3—Mo2—OB2	101.59 (16)	Al1—OW3—H8	111.0
OT4—Mo2—OB3	99.29 (18)	Al1—OW3—H9	125.4
OT3—Mo2—OB3	97.85 (16)	H8—OW3—H9	120.8
OB2—Mo2—OB3	149.30 (13)	H10—OW4—H11	107.7
OT4—Mo2—OH2	162.45 (15)	H12—OW5—H13	108.5
OT3—Mo2—OH2	90.88 (16)	H14—OW6—H15	107.7
OB2—Mo2—OH2	72.01 (13)	H16—OW7—H17	107.5
OB3—Mo2—OH2	84.24 (13)	H18—OW8—H19	107.7

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

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
OH3—H3···OT1ⁱⁱⁱ	0.85	1.85	2.681 (4)	167
OH1—H1···OB2ⁱⁱⁱ	0.85	2.10	2.944 (4)	172
OH2—H2···OW5^iv	0.85	1.82	2.665 (5)	178
OW3—H8···OT4^v	0.85	1.83	2.628 (5)	156
OW3—H9···OW7^v	0.85	1.81	2.632 (5)	163
OW1—H4···OW7	0.85	2.01	2.730 (5)	142
OW1—H5···OW4^vi	0.85	1.74	2.577 (5)	167
OW2—H6···OB3ⁱ	0.85	1.72	2.559 (4)	171
OW2—H7···OW6	0.85	1.88	2.728 (5)	178
OW4—H10···OB1^vii	0.85	1.94	2.737 (5)	156
OW5—H12···OT1^viii	0.86	2.15	3.002 (6)	179
OW5—H13···OW6^ix	0.85	1.99	2.842 (6)	180
OW6—H14···OW5ⁱ	0.85	2.04	2.800 (6)	149
OW6—H15···OT3^v	0.85	2.45	3.091 (6)	133
OW7—H16···OT3^v	0.85	2.13	2.878 (5)	146
OW7—H17···OW8	0.85	1.98	2.759 (5)	152
OW8—H18···OT1^x	0.85	2.19	2.902 (5)	141
OW8—H18···OT6^xi	0.85	2.62	3.241 (5)	131
OW8—H19···OW8^xii	0.85	2.56	3.283 (6)	144

Symmetry codes: (i) −x, −y+1, −z+1; (iii) −x+1, −y, −z; (iv) −x, −y+1, −z; (v) −x+1, −y+1, −z+1; (vi) x−1, y, z; (vii) x+1, y, z+1; (viii) −x+1, −y+1, −z; (ix) x, y, z−1; (x) x, y, z+1; (xi) −x, −y, −z+1; (xii) −x+1, −y, −z+1.

Experimental details

Crystal data
Chemical formula	[Al(H₂O)₆][Cr(OH)₆Mo₆O₁₈]·10H₂O
M_r	1332.92
Crystal system, space group	Triclinic, P1
Temperature (K)	290
a, b, c (Å)	6.809 (5), 11.267 (7), 11.596 (9)
α, β, γ (°)	101.26 (3), 97.02 (3), 101.81 (3)
V (Å³)	841.7 (10)
Z	1
Radiation type	Mo Kα
µ (mm⁻¹)	2.63
Crystal size (mm)	0.12 × 0.12 × 0.11

Data collection
Diffractometer	Rigaku R-AXIS RAPID diffractometer
Absorption correction	Multi-scan (ABSCOR; Higashi, 1995)
T_min, T_max	0.745, 0.770
No. of measured, independent and observed [I > 2σ(I)] reflections	8257, 3801, 3346
R_int	0.037
(sin θ/λ)_max (Å⁻¹)	0.649

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.033, 0.093, 1.10
No. of reflections	3801
No. of parameters	217
No. of restraints	24
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.89, −0.86

Computer programs: RAPID-AUTO (Rigaku, 1998), CrystalStructure (Rigaku/MSC, 2002), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), PLATON (Spek, 2009).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
OH3—H3···OT1ⁱ	0.85	1.85	2.681 (4)	166.8
OH1—H1···OB2ⁱ	0.85	2.10	2.944 (4)	172.4
OH2—H2···OW5ⁱⁱ	0.85	1.82	2.665 (5)	178.1
OW3—H8···OT4ⁱⁱⁱ	0.85	1.83	2.628 (5)	156.2
OW3—H9···OW7ⁱⁱⁱ	0.85	1.81	2.632 (5)	163.4
OW1—H4···OW7	0.85	2.01	2.730 (5)	142.1
OW1—H5···OW4^iv	0.85	1.74	2.577 (5)	167.2
OW2—H6···OB3^v	0.85	1.72	2.559 (4)	170.5
OW2—H7···OW6	0.85	1.88	2.728 (5)	177.8
OW4—H10···OB1^vi	0.85	1.94	2.737 (5)	155.5
OW5—H12···OT1^vii	0.86	2.15	3.002 (6)	179.1
OW5—H13···OW6^viii	0.85	1.99	2.842 (6)	179.8
OW6—H14···OW5^v	0.85	2.04	2.800 (6)	149.2
OW6—H15···OT3ⁱⁱⁱ	0.85	2.45	3.091 (6)	133.0
OW7—H16···OT3ⁱⁱⁱ	0.85	2.13	2.878 (5)	146.0
OW7—H17···OW8	0.85	1.98	2.759 (5)	151.6
OW8—H18···OT1^ix	0.85	2.19	2.902 (5)	140.9
OW8—H18···OT6^x	0.85	2.62	3.241 (5)	130.7
OW8—H19···OW8^xi	0.85	2.56	3.283 (6)	143.5

Symmetry codes: (i) −x+1, −y, −z; (ii) −x, −y+1, −z; (iii) −x+1, −y+1, −z+1; (iv) x−1, y, z; (v) −x, −y+1, −z+1; (vi) x+1, y, z+1; (vii) −x+1, −y+1, −z; (viii) x, y, z−1; (ix) x, y, z+1; (x) −x, −y, −z+1; (xi) −x+1, −y, −z+1.

Acknowledgements

This work was supported financially by the National Basic Research Program of China (2007CB808003) and the National Natural Science Foundation of China (20973082, 20921003, 20703019).

References

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