Lithium diaqua­magnesium catena-borodiphosphate(V) monohydrate, LiMg(H2O)2[BP2O8]·H2O, at 173 K

Lin, J.-R.; Huang, Y.-X.; Wu, Y.-H.; Zhou, Y.

doi:10.1107/S160053680801516X

inorganic compounds

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ISSN: 2056-9890

Volume 64| Part 6| June 2008| Pages i39-i40

doi:10.1107/S160053680801516X

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Lithium diaquamagnesium catena-borodiphosphate(V) monohydrate, LiMg(H₂O)₂[BP₂O₈]·H₂O, at 173 K

Jin-Ru Lin,^a Ya-Xi Huang,^a ^* Yu-Huan Wu ^a and Yan Zhou ^a

^aDepartment of Materials Science and Engineering, College of Materials, Xiamen University, Xiamen 361005, Fujian Province, People's Republic of China
^*Correspondence e-mail: yaxihuang@xmu.edu.cn

(Received 5 May 2008; accepted 20 May 2008; online 24 May 2008)

The crystal structure of LiMg(H₂O)₂[BP₂O₈]·H₂O consists of tubular structural units, built from tetrahedral _∞¹{[BP₂O₈]³⁻} borophosphate ribbons and (LiO₄)_n helices running along [001], which are interconnected by MgO₄(H₂O)₂ octahedra, forming a three-dimensional network structure with one-dimensional channels along [001] in which the water molecules are located. The water molecule in the channel is significantly displaced by up to 0.3 Å from the special position 6b (..2) to a half-occupied general position. Mg, B and one Li atom all lie on twofold axes. Of the two Li positions, one is at a special position 6b (..2), while the other is at a general position; both are only half-occupied.

Related literature

For NaMg(H₂O)₂[BP₂O₈]·H₂O and KMg(H₂O)₂[BP₂O₈]·H₂O, see: Kniep et al. (1997 ). For LiCu(H₂O)₂[BP₂O₈]·(H₂O) and LiZn(H₂O)₂[BP₂O₈]·H₂O, see: Boy & Kniep (2001a ,b ). For LiCd(H₂O)₂[BP₂O₈]·H₂O, see: Ge et al. (2003 ).

Experimental

Crystal data

LiMg(H₂O)₂[BP₂O₈]·H₂O
M_r = 286.05
Hexagonal, P 6₅ 22
a = 9.4139 (1) Å
c = 15.7113 (3) Å
V = 1205.82 (3) Å³
Z = 6
Mo Kα radiation
μ = 0.67 mm⁻¹
T = 173 (2) K
0.16 × 0.07 × 0.07 mm

Data collection

Oxford Diffraction Gemini R Ultra CCD area-detector diffractometer
Absorption correction: numerical (CrysAlis RED; Oxford Diffraction, 2005 $[Oxford Diffraction (2005). CrysAlis CCD and CrysAlis RED. Oxford Diffraction Ltd, Abingdon, Oxfordshire, England.]$ ) T_min = 0.900, T_max = 0.954
3404 measured reflections
1343 independent reflections
1142 reflections with I > 2σ(I)
R_int = 0.033

Refinement

R[F² > 2σ(F²)] = 0.037
wR(F²) = 0.092
S = 1.06
1343 reflections
75 parameters
H-atom parameters not refined
Δρ_max = 0.74 e Å⁻³
Δρ_min = −0.55 e Å⁻³
Absolute structure: Flack (1983 ), 410 Friedel pairs
Flack parameter: −0.1 (2)

Table 1
Selected geometric parameters (Å, °)

P1—O3	1.501 (2)
P1—O4	1.5033 (19)
P1—O1ⁱ	1.558 (2)
P1—O2ⁱⁱ	1.5632 (17)
Mg1—O4ⁱ	2.042 (2)
Mg1—O3ⁱⁱⁱ	2.0590 (17)
Mg1—O5	2.179 (2)
B1—O1ⁱⁱ	1.461 (3)
B1—O2^iv	1.469 (3)
Li1—O3^v	2.113 (12)
Li1—O5^v	2.135 (2)
Li1—O6^vi	2.35 (2)
Li2—O6^vii	1.82 (2)
Li2—O4^vii	2.08 (2)
Li2—O6^viii	2.08 (2)
Li2—O5^ix	2.10 (2)

B1^x—O1—P1^x	128.00 (16)
B1—O2—P1ⁱⁱ	130.40 (17)
P1—O3—Mg1	130.05 (11)
Symmetry codes: (i) $[y, -x+y+1, z+{\script{1\over 6}}]$ ; (ii) x-y+1, -y+2, -z; (iii) $[-x+y, y, -z+{\script{1\over 2}}]$ ; (iv) $[-y+2, -x+2, -z+{\script{1\over 6}}]$ ; (v) $[-y+1, -x+1, -z+{\script{1\over 6}}]$ ; (vi) $[x-y, x, z-{\script{1\over 6}}]$ ; (vii) $[-x+y+1, y, -z+{\script{1\over 2}}]$ ; (viii) $[y, x, -z+{\script{2\over 3}}]$ ; (ix) $[y, -x+y, z+{\script{1\over 6}}]$ ; (x) $[x-y+1, x, z-{\script{1\over 6}}]$ .

Table 2
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O5—H1⋯O4ⁱⁱⁱ	0.86	2.09	2.852 (3)	148
O5—H2⋯O2^xi	0.88	1.98	2.779 (3)	151
O5—H2⋯O3^v	0.88	2.46	3.198 (3)	142
Symmetry codes: (iii) $[-x+y, y, -z+{\script{1\over 2}}]$ ; (v) $[-y+1, -x+1, -z+{\script{1\over 6}}]$ ; (xi) $[y-1, -x+y, z+{\script{1\over 6}}]$ .

Data collection: CrysAlis CCD (Oxford Diffraction, 2005 $[Oxford Diffraction (2005). CrysAlis CCD and CrysAlis RED. Oxford Diffraction Ltd, Abingdon, Oxfordshire, England.]$ ); cell refinement: CrysAlis CCD; data reduction: CrysAlis RED (Oxford Diffraction, 2005 $[Oxford Diffraction (2005). CrysAlis CCD and CrysAlis RED. Oxford Diffraction Ltd, Abingdon, Oxfordshire, England.]$ ); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 1997-2004 ) and ATOMS (Dowty, 2004 ); software used to prepare material for publication: SHELXL97.

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S160053680801516X/br2074sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S160053680801516X/br2074Isup2.hkl

checkCIF report

Comment top

In the last decade, much attention has been paid to the large family of borophosphates with the general formula AM(H₂O)₂[BP₂O₈].yH₂O (A^I=Li, Na, K, NH₄⁺; M^II=Mg, Mn, Fe, Co, Ni, Cu, Zn, Cd)(where y = 0.5–1) due to their chiral structure property and potential applications for catalysts (Kniep et al., 1997; Ewald et al., 2007). Many combinations between monovalent A cations and divalent M cations are available. At the M site, most of the known compounds in this family apply transition metal ions, while only two magnesium components, NaMg(H₂O)₂[BP₂O₈].H₂O as well as KMg(H₂O)₂[BP₂O₈].H₂O, are listed for the inclusion of alkaline-earth metals (Kniep et al., 1997). Whereas at the A site, up to date, only three Li-based borophosphates are known, e.g. LiCu(H₂O)₂[BP₂O₈].(H₂O) (Boy & Kniep, 2001a), LiZn(H₂O)₂[BP₂O₈].H₂O (Boy & Kniep, 2001b) and LiCd(H₂O)₂[BP₂O₈].H₂O (Ge et al., 2003). Therefore herein we report on a new member of this family with the combination of Li and Mg, LiMg(H₂O)₂[BP₂O₈].H₂O.

The crystal structure of the title compound contains infinite one-dimensional helical borophosphate ribbons _∞¹{[BP₂O₈]^3-}, arranged around 6₅ screw axes, which are built up from four-membered rings of corner-sharing PO₄ and BO₄ tetrahedra (Fig. 1 & 2). There are two partially occupied Li positions. Li1, located at the outside of ribbons (Fig. 2), is fixed by an irregular arrangement of five oxygen atoms from adjacent phosphate groups (O3) and water molecules (O5, O6). Li2 is tetrahedrally coordinated by four oxygen atoms that originated from phosphate groups (O4) and two water molecules (O5, O6)(Fig. 3). The resulting distorted tetrahedra, (Li2O₄)_n, located at the free thread of the borophosphate ribbons, are also wound around 6₅ screw axes to form helices via corner-sharing oxygen atoms which further connect the above infinite one-dimensional borophosphate ribbons by sharing common oxygen corners to develop into a tubular structure where water molecules (O6) with a disorder mode reside in. The magnesium site is octahedrally coordinated by four oxygen atoms from phosphate tetrahedra (O3, O4) and two water molecules (O5) which are located between the adjacent tubes and connect the neighbouring tubes to form a three-dimensional framework.

Related literature top

For the related structures NaMg(H₂O)₂[BP₂O₈].H₂O and KMg(H₂O)₂[BP₂O₈].H₂O, see: Kniep et al. (1997). For LiCu(H₂O)₂[BP₂O₈].(H₂O) and LiZn(H₂O)₂[BP₂O₈].H₂O, see: Boy & Kniep (2001a,b). For LiCd(H₂O)₂[BP₂O₈].H₂O, see: Ge et al. (2003).

Experimental top

Transparent, colorless single crystals of the title compound were hydrothermally synthesized. A mixture of MgCl₂.6H₂O (0.5344 g), LiOH.H₂O (5.042 g), H₃BO₃ (1.568 g) and 10 ml (85%) H₃PO₄ in an approximate molar ratio Mg:Li:B:P = 1:46:10:65, are dissolved in 5 ml distilled water while stirring. The resulting solution (pH = 1.5) was transferred into a Teflon-lined autoclave (internal volume 30 ml, degree of filling 67%) and held at 463 K for four days under autogenous pressure. Then the autoclave was cooled to room temperature by turning off the power. Products were filtered off, washed with distilled water and dried at room temperature. Crystals with hexagonal bipyramidal morphology were selected for single-crystal diffraction after checking under a polarizing microscope and identifying by X-ray powder diffraction.

Computing details top

Data collection: CrysAlis CCD (Oxford Diffraction, 2005); cell refinement: CrysAlis CCD (Oxford Diffraction, 2005); data reduction: CrysAlis RED (Oxford Diffraction, 2005); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 1997-2004) and ATOMS (Dowty, 2004); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top

	Fig. 1. Helical arrangements in the crystal structure of LiMg(H₂O)₂[BP₂O₈].H₂O, Green tetrahedra: PO₄, Orange tetrahedra: BO₄, grey tetrahedra: Li2O₄.
	Fig. 2. The crystal structure of LiMg(H₂O)₂[BP₂O₈].H₂O plotted in projection along [001]
	Fig. 3. The coordination environment of the metal atoms in LiMg(H₂O)₂[BP₂O₈].H₂O, with displacement ellipsoids drawn at the 50% probability level.(symmetry codes: (i) y, x, -1/3 - z; (ii) x-y, 1 - y, -z; (iii) x, 1 + x-y, -1/6 - z; (iv) 1 - x,1 - y,-1/2 + z; (v) -x + y, 1 - x, -2/3 + z; (vi) 1 + x-y, x, -1/6 + z; (vii) y, 1 - x + y, -5/6 + z; (viii) -x + y, y, -1/2 - z; (ix) 1 + x-y, 2 - y, -z)

Lithium diaquamagnesium catena-borodiphosphate(V) monohydrate top

Crystal data top

LiMg(H₂O)₂[BP₂O₈]·H₂O	D_x = 2.364 Mg m⁻³
M_r = 286.05	Mo Kα radiation, λ = 0.71073 Å
Hexagonal, P6₅22	Cell parameters from 3404 reflections
Hall symbol: P 65 2 (0 0 1)	θ = 2.8–32.6°
a = 9.4139 (1) Å	µ = 0.67 mm⁻¹
c = 15.7113 (3) Å	T = 173 K
V = 1205.82 (3) Å³	Hexagonal bipyramidal, colourless
Z = 6	0.16 × 0.07 × 0.07 mm
F(000) = 864

Data collection top

Oxford Diffraction CCD area-detector diffractometer	1343 independent reflections
Radiation source: fine-focus sealed tube	1142 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.033
326 images,Δω=1°, Exp time: 40 s. scans	θ_max = 32.6°, θ_min = 2.8°
Absorption correction: numerical (CrysAlis RED; Oxford Diffraction, 2005)	h = −7→14
T_min = 0.900, T_max = 0.954	k = −13→14
3404 measured reflections	l = −22→8

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)] = 0.037	H-atom parameters not refined
wR(F²) = 0.092	w = 1/[σ²(F_o²) + (0.0493P)²] where P = (F_o² + 2F_c²)/3
S = 1.06	(Δ/σ)_max < 0.001
1343 reflections	Δρ_max = 0.74 e Å⁻³
75 parameters	Δρ_min = −0.55 e Å⁻³
0 restraints	Absolute structure: Flack (1983), 410 Friedel pairs
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: −0.1 (2)

Crystal data top

LiMg(H₂O)₂[BP₂O₈]·H₂O	Z = 6
M_r = 286.05	Mo Kα radiation
Hexagonal, P6₅22	µ = 0.67 mm⁻¹
a = 9.4139 (1) Å	T = 173 K
c = 15.7113 (3) Å	0.16 × 0.07 × 0.07 mm
V = 1205.82 (3) Å³

Data collection top

Oxford Diffraction CCD area-detector diffractometer	1343 independent reflections
Absorption correction: numerical (CrysAlis RED; Oxford Diffraction, 2005)	1142 reflections with I > 2σ(I)
T_min = 0.900, T_max = 0.954	R_int = 0.033
3404 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.037	H-atom parameters not refined
wR(F²) = 0.092	Δρ_max = 0.74 e Å⁻³
S = 1.06	Δρ_min = −0.55 e Å⁻³
1343 reflections	Absolute structure: Flack (1983), 410 Friedel pairs
75 parameters	Absolute structure parameter: −0.1 (2)
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	Occ. (<1)
P1	0.61413 (8)	0.82894 (8)	0.08573 (4)	0.00616 (14)
Mg1	0.44657 (8)	0.89313 (15)	0.2500	0.0080 (3)
O1	0.8112 (2)	0.7888 (2)	−0.06431 (11)	0.0096 (4)
O2	0.7643 (2)	1.1783 (2)	0.01261 (10)	0.0074 (4)
O3	0.4841 (2)	0.8559 (2)	0.12481 (11)	0.0113 (4)
O4	0.6190 (3)	0.6808 (2)	0.11749 (11)	0.0116 (4)
O5	0.1958 (3)	0.7110 (3)	0.21628 (13)	0.0168 (5)
B1	0.8496 (2)	1.1504 (2)	0.0833	0.0082 (7)
O6	0.8943 (11)	0.8068 (7)	0.2666 (4)	0.0528 (18)*	0.50
Li1	0.2395 (13)	0.7605 (13)	0.0833	0.027 (3)*	0.426 (18)
Li2	0.893 (3)	0.750 (3)	0.3456 (13)	0.027 (3)*	0.287 (9)
H1	0.1273	0.6655	0.2575	0.050*
H2	0.1925	0.6306	0.1868	0.050*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
P1	0.0073 (3)	0.0063 (3)	0.0050 (2)	0.0035 (2)	0.0006 (2)	−0.0002 (2)
Mg1	0.0081 (4)	0.0074 (6)	0.0084 (5)	0.0037 (3)	0.0018 (4)	0.000
O1	0.0103 (9)	0.0091 (9)	0.0108 (8)	0.0060 (8)	−0.0029 (7)	−0.0014 (7)
O2	0.0090 (9)	0.0091 (9)	0.0045 (7)	0.0048 (8)	−0.0006 (6)	0.0004 (6)
O3	0.0124 (9)	0.0166 (11)	0.0067 (8)	0.0087 (8)	0.0006 (7)	−0.0030 (7)
O4	0.0186 (10)	0.0074 (9)	0.0098 (7)	0.0073 (8)	−0.0013 (8)	0.0012 (7)
O5	0.0132 (11)	0.0124 (10)	0.0160 (9)	−0.0002 (9)	0.0040 (8)	−0.0044 (8)
B1	0.0100 (14)	0.0100 (14)	0.0065 (15)	0.0063 (16)	−0.0018 (13)	−0.0018 (13)

Geometric parameters (Å, º) top

P1—O3	1.501 (2)	B1—O1ⁱ	1.461 (3)
P1—O4	1.5033 (19)	B1—O2^ix	1.469 (3)
P1—O1ⁱ	1.558 (2)	B1—O2	1.469 (3)
P1—O2ⁱⁱ	1.5632 (17)	O6—O6ⁱⁱⁱ	0.549 (14)
P1—Li2ⁱⁱⁱ	2.94 (2)	Li1—O3^x	2.113 (12)
Mg1—O4ⁱ	2.042 (2)	Li1—O5^x	2.135 (2)
Mg1—O4^iv	2.042 (2)	Li1—O6^vi	2.35 (2)
Mg1—O3^v	2.0590 (17)	Li1—O6^iv	2.35 (2)
Mg1—O3	2.0590 (17)	Li1—Li2^iv	2.40 (3)
Mg1—O5	2.179 (2)	Li2—O6ⁱⁱⁱ	1.82 (2)
Mg1—O5^v	2.179 (2)	Li2—O4ⁱⁱⁱ	2.08 (2)
Mg1—Li2^vi	3.07 (2)	Li2—O6^vii	2.08 (2)
Mg1—Li2^vii	3.07 (2)	Li2—O5^xi	2.10 (2)
Mg1—Li1^viii	3.128 (4)	Li2—Li2^vii	2.36 (4)
Mg1—Li1	3.128 (4)	Li2—O6ⁱ	2.48 (2)
B1—O1ⁱⁱ	1.461 (3)	Li2—O1^xii	2.65 (2)

O3—P1—O4	115.28 (12)	Li2ⁱⁱⁱ—O6—Li2^vii	116.4 (10)
O3—P1—O1ⁱ	111.30 (11)	Li2—O6—Li1^xi	75.9 (9)
O4—P1—O1ⁱ	105.63 (11)	Li2ⁱⁱⁱ—O6—Li1^xi	69.1 (7)
O3—P1—O2ⁱⁱ	106.09 (10)	Li2^vii—O6—Li1^xi	114.4 (7)
O4—P1—O2ⁱⁱ	111.75 (10)	Li2—O6—Li2^xiii	117.5 (12)
O1ⁱ—P1—O2ⁱⁱ	106.53 (10)	Li2ⁱⁱⁱ—O6—Li2^xiii	64.5 (10)
O3—P1—Li2ⁱⁱⁱ	134.1 (4)	Li2^vii—O6—Li2^xiii	142.5 (11)
O1ⁱ—P1—Li2ⁱⁱⁱ	63.9 (4)	Li1^xi—O6—Li2^xiii	101.1 (6)
O2ⁱⁱ—P1—Li2ⁱⁱⁱ	119.2 (4)	O3^x—Li1—O3	109.7 (9)
O4ⁱ—Mg1—O4^iv	95.33 (13)	O3^x—Li1—O5^x	80.9 (3)
O4ⁱ—Mg1—O3^v	91.45 (8)	O3—Li1—O5^x	97.7 (4)
O4^iv—Mg1—O3^v	99.96 (8)	O3^x—Li1—O5	97.7 (4)
O4ⁱ—Mg1—O3	99.96 (8)	O3—Li1—O5	80.9 (3)
O4^iv—Mg1—O3	91.45 (8)	O5^x—Li1—O5	177.4 (11)
O3^v—Mg1—O3	163.06 (13)	O3^x—Li1—O6^vi	125.3 (5)
O4ⁱ—Mg1—O5	178.78 (8)	O3—Li1—O6^vi	124.4 (5)
O4^iv—Mg1—O5	85.31 (9)	O5^x—Li1—O6^vi	98.0 (6)
O3^v—Mg1—O5	87.42 (8)	O5—Li1—O6^vi	84.6 (5)
O3—Mg1—O5	81.04 (8)	O3^x—Li1—O6^iv	124.4 (5)
O4ⁱ—Mg1—O5^v	85.31 (9)	O3—Li1—O6^iv	125.3 (5)
O4^iv—Mg1—O5^v	178.78 (8)	O5^x—Li1—O6^iv	84.6 (5)
O3^v—Mg1—O5^v	81.04 (8)	O5—Li1—O6^iv	98.0 (6)
O3—Mg1—O5^v	87.42 (8)	O6^vi—Li1—O6^iv	13.5 (4)
O5—Mg1—O5^v	94.06 (13)	O6—Li2—O6ⁱⁱⁱ	10.0 (7)
B1^xiii—O1—P1^xiii	128.00 (16)	O6—Li2—O4ⁱⁱⁱ	121.6 (14)
B1^xiii—O1—Li2^xii	147.5 (5)	O6ⁱⁱⁱ—Li2—O4ⁱⁱⁱ	112.3 (11)
P1^xiii—O1—Li2^xii	84.3 (5)	O6—Li2—O6^vii	92.9 (11)
B1—O2—P1ⁱⁱ	130.40 (17)	O6ⁱⁱⁱ—Li2—O6^vii	102.9 (10)
P1—O3—Mg1	130.05 (11)	O4ⁱⁱⁱ—Li2—O6^vii	134.3 (10)
P1—O3—Li1	127.6 (4)	O6—Li2—O5^xi	121.0 (13)
Mg1—O3—Li1	97.1 (2)	O6ⁱⁱⁱ—Li2—O5^xi	119.2 (11)
P1—O4—Mg1^xiii	141.40 (12)	O4ⁱⁱⁱ—Li2—O5^xi	86.5 (8)
P1—O4—Li2ⁱⁱⁱ	109.2 (6)	O6^vii—Li2—O5^xi	101.1 (9)
Mg1^xiii—O4—Li2ⁱⁱⁱ	96.3 (6)	O6—Li2—O6ⁱ	102.1 (12)
Li2^vi—O5—Li1	69.3 (8)	O6ⁱⁱⁱ—Li2—O6ⁱ	112.0 (10)
Li2^vi—O5—Mg1	91.8 (6)	O4ⁱⁱⁱ—Li2—O6ⁱ	125.2 (9)
Li1—O5—Mg1	92.95 (17)	O6^vii—Li2—O6ⁱ	9.6 (4)
O1ⁱⁱ—B1—O1ⁱ	102.5 (3)	O5^xi—Li2—O6ⁱ	98.5 (8)
O1ⁱⁱ—B1—O2	112.10 (10)	O6—Li2—O1^xii	99.7 (11)
O1ⁱ—B1—O2	114.14 (10)	O6ⁱⁱⁱ—Li2—O1^xii	98.7 (9)
O1ⁱⁱ—B1—O2^ix	114.14 (10)	O4ⁱⁱⁱ—Li2—O1^xii	60.6 (6)
O1ⁱ—B1—O2^ix	112.10 (10)	O6^vii—Li2—O1^xii	86.7 (7)
O2—B1—O2^ix	102.2 (3)	O5^xi—Li2—O1^xii	137.7 (9)
Li2—O6—Li2ⁱⁱⁱ	144.4 (15)	O6ⁱ—Li2—O1^xii	82.4 (6)
Li2—O6—Li2^vii	84.1 (12)

Symmetry codes: (i) y, −x+y+1, z+1/6; (ii) x−y+1, −y+2, −z; (iii) −x+y+1, y, −z+1/2; (iv) −x+1, −x+y+1, −z+1/3; (v) −x+y, y, −z+1/2; (vi) x−y, x, z−1/6; (vii) y, x, −z+2/3; (viii) −x+y, −x+1, z+1/3; (ix) −y+2, −x+2, −z+1/6; (x) −y+1, −x+1, −z+1/6; (xi) y, −x+y, z+1/6; (xii) −x+2, −x+y+1, −z+1/3; (xiii) x−y+1, x, z−1/6.

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O5—H1···O4^v	0.862	2.085	2.852 (3)	147.93
O5—H2···O2^xiv	0.875	1.979	2.779 (3)	151.43
O5—H2···O3^x	0.875	2.463	3.198 (3)	141.96

Symmetry codes: (v) −x+y, y, −z+1/2; (x) −y+1, −x+1, −z+1/6; (xiv) y−1, −x+y, z+1/6.

Experimental details

Crystal data
Chemical formula	LiMg(H₂O)₂[BP₂O₈]·H₂O
M_r	286.05
Crystal system, space group	Hexagonal, P6₅22
Temperature (K)	173
a, c (Å)	9.4139 (1), 15.7113 (3)
V (Å³)	1205.82 (3)
Z	6
Radiation type	Mo Kα
µ (mm⁻¹)	0.67
Crystal size (mm)	0.16 × 0.07 × 0.07

Data collection
Diffractometer	Oxford Diffraction CCD area-detector diffractometer
Absorption correction	Numerical (CrysAlis RED; Oxford Diffraction, 2005)
T_min, T_max	0.900, 0.954
No. of measured, independent and observed [I > 2σ(I)] reflections	3404, 1343, 1142
R_int	0.033
(sin θ/λ)_max (Å⁻¹)	0.758

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.037, 0.092, 1.06
No. of reflections	1343
No. of parameters	75
H-atom treatment	H-atom parameters not refined
Δρ_max, Δρ_min (e Å⁻³)	0.74, −0.55
Absolute structure	Flack (1983), 410 Friedel pairs
Absolute structure parameter	−0.1 (2)

Computer programs: CrysAlis CCD (Oxford Diffraction, 2005), CrysAlis RED (Oxford Diffraction, 2005), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), DIAMOND (Brandenburg, 1997-2004) and ATOMS (Dowty, 2004).

Selected geometric parameters (Å, º) top

P1—O3	1.501 (2)	B1—O2^iv	1.469 (3)
P1—O4	1.5033 (19)	Li1—O3^v	2.113 (12)
P1—O1ⁱ	1.558 (2)	Li1—O5^v	2.135 (2)
P1—O2ⁱⁱ	1.5632 (17)	Li1—O6^vi	2.35 (2)
Mg1—O4ⁱ	2.042 (2)	Li2—O6^vii	1.82 (2)
Mg1—O3ⁱⁱⁱ	2.0590 (17)	Li2—O4^vii	2.08 (2)
Mg1—O5	2.179 (2)	Li2—O6^viii	2.08 (2)
B1—O1ⁱⁱ	1.461 (3)	Li2—O5^ix	2.10 (2)

B1^x—O1—P1^x	128.00 (16)	P1—O3—Mg1	130.05 (11)
B1—O2—P1ⁱⁱ	130.40 (17)

Symmetry codes: (i) y, −x+y+1, z+1/6; (ii) x−y+1, −y+2, −z; (iii) −x+y, y, −z+1/2; (iv) −y+2, −x+2, −z+1/6; (v) −y+1, −x+1, −z+1/6; (vi) x−y, x, z−1/6; (vii) −x+y+1, y, −z+1/2; (viii) y, x, −z+2/3; (ix) y, −x+y, z+1/6; (x) x−y+1, x, z−1/6.

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O5—H1···O4ⁱⁱⁱ	0.862	2.085	2.852 (3)	147.93
O5—H2···O2^xi	0.875	1.979	2.779 (3)	151.43
O5—H2···O3^v	0.875	2.463	3.198 (3)	141.96

Symmetry codes: (iii) −x+y, y, −z+1/2; (v) −y+1, −x+1, −z+1/6; (xi) y−1, −x+y, z+1/6.

Acknowledgements

This project was supported by the National Natural Science Foundation of China (No. 40472027).

References

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