Heptamagnesium bis-(phosphate) tetra-kis-(hydrogen phosphate) with strong hydrogen bonds: Mg(7)(PO(4))(2)(HPO(4))(4).

The title compound, Mg(7)(PO(4))(2)(HPO(4))(4), was synthesized by the hydro-thermal method. The structure is based on a framework of edge- and corner-sharing MgO(6) and MgO(4)(OH)(2) octa-hedra, an MgO(5) polyhedron, PO(4) and PO(3)(OH) tetra-hedra. All atoms are in general positions except for one Mg atom, which is located on a crystallographic inversion centre. The OH groups, bridging Mg-(OH)-P, are involved in strong hydrogen bonds. Compounds with the general formula M(7)(PO(4))(2)(HPO(4))(4) (M = Mg, Mn, Fe and Co) are all isostructural with their homologue arsenate Mg(7)(AsO(4))(2)(HAsO(4))(4).

Related literature

For background to metal phosphates, see: Viter & Nagornyi (2009 ▶); Clearfield (1988 ▶); Trad et al. (2010 ▶). For the hydro­thermal method, see: Assani et al. (2010 ▶, 2011 ▶). For isostructural compounds, see: Zhou et al. (2002 ▶); Riou et al. (1987 ▶); Rojo et al. (2002 ▶); Lightfoot & Cheetham (1988 ▶); Kolitsch & Bartu (2004 ▶).

Experimental

Crystal data

Mg7(PO4)2(HPO4)4

M = 744.02

Triclinic,

a = 6.4204 (5) Å

b = 7.8489 (4) Å

c = 9.4315 (5) Å

α = 104.442 (3)°

β = 108.505 (5)°

γ = 101.189 (8)°

V = 416.70 (4) Å3

Z = 1

Mo Kα radiation

μ = 1.06 mm−1

T = 296 K

0.16 × 0.10 × 0.07 mm

Data collection

Bruker X8 APEX Diffractometer

Absorption correction: multi-scan (SADABS; Bruker, 2005 ▶) T min = 0.881, T max = 0.929

9421 measured reflections

1923 independent reflections

1715 reflections with I > 2σ(I)

R int = 0.036

Refinement

R[F 2 > 2σ(F 2)] = 0.026

wR(F 2) = 0.072

S = 1.07

1923 reflections

169 parameters

H-atom parameters constrained

Δρmax = 0.43 e Å−3

Δρmin = −0.42 e Å−3

Data collection: APEX2 (Bruker, 2005 ▶); cell refinement: SAINT (Bruker, 2005 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997 ▶) and DIAMOND (Brandenburg, 2006 ▶); software used to prepare material for publication: WinGX publication routines (Farrugia, 1999 ▶).

Crystal structure: contains datablock(s) I. DOI: 10.1107/S1600536811036361/bt5638sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811036361/bt5638Isup2.hkl

Supplementary material file. DOI: 10.1107/S1600536811036361/bt5638Isup3.cml

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Mg7(PO4)2(HPO4)4	Z = 1
Mr = 744.02	F(000) = 370
Triclinic, P1	Dx = 2.965 Mg m−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 6.4204 (5) Å	Cell parameters from 1923 reflections
b = 7.8489 (4) Å	θ = 2.4–27.6°
c = 9.4315 (5) Å	µ = 1.06 mm−1
α = 104.442 (3)°	T = 296 K
β = 108.505 (5)°	Parallelepipedic, colourless
γ = 101.189 (8)°	0.16 × 0.10 × 0.07 mm
V = 416.70 (4) Å3

Bruker X8 APEX Diffractometer	1923 independent reflections
Radiation source: fine-focus sealed tube	1715 reflections with I > 2σ(I)
graphite	Rint = 0.036
φ and ω scans	θmax = 27.6°, θmin = 2.4°
Absorption correction: multi-scan (SADABS; Bruker, 2005)	h = −8→8
Tmin = 0.881, Tmax = 0.929	k = −10→10
9421 measured reflections	l = −11→12

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)] = 0.026	Hydrogen site location: difference Fourier map
wR(F2) = 0.072	H-atom parameters constrained
S = 1.07	w = 1/[σ2(Fo2) + (0.0325P)2 + 0.6237P] where P = (Fo2 + 2Fc2)/3
1923 reflections	(Δ/σ)max < 0.001
169 parameters	Δρmax = 0.43 e Å−3
0 restraints	Δρmin = −0.42 e Å−3

Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'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.

	x	y	z	Uiso*/Ueq
Mg1	−0.38348 (12)	0.54390 (10)	−0.10950 (8)	0.00639 (17)
Mg2	0.0000	0.0000	0.0000	0.0094 (2)
Mg3	−0.05324 (13)	0.28758 (10)	−0.51536 (9)	0.00821 (17)
Mg4	−0.27778 (13)	0.19081 (11)	−0.28530 (9)	0.00902 (17)
P1	0.22691 (9)	0.14512 (8)	−0.22413 (6)	0.00561 (13)
P2	0.08899 (9)	0.58025 (7)	−0.17255 (6)	0.00465 (13)
P3	−0.59090 (9)	0.23141 (8)	−0.62865 (7)	0.00658 (14)
O1	0.0189 (3)	0.1762 (2)	−0.33779 (18)	0.0081 (3)
O2	0.2208 (3)	0.1877 (2)	−0.05694 (18)	0.0074 (3)
O3	0.4517 (3)	0.2446 (2)	−0.22968 (18)	0.0077 (3)
O4	0.2013 (3)	−0.0667 (2)	−0.27972 (18)	0.0091 (3)
H4	0.1828	−0.1148	−0.2104	0.011*
O5	0.3069 (3)	0.5385 (2)	−0.08555 (18)	0.0068 (3)
O6	0.0589 (3)	0.5452 (2)	−0.34643 (18)	0.0073 (3)
O7	0.1098 (3)	0.7857 (2)	−0.09645 (19)	0.0094 (3)
O8	−0.1240 (3)	0.4602 (2)	−0.16487 (18)	0.0070 (3)
O9	−0.3803 (3)	0.2112 (2)	−0.50853 (19)	0.0104 (3)
O10	−0.5267 (3)	0.3827 (2)	−0.69363 (19)	0.0106 (3)
O11	−0.7360 (3)	0.0488 (2)	−0.76029 (19)	0.0097 (3)
O12	−0.7344 (3)	0.2950 (2)	−0.52719 (19)	0.0111 (3)
H12	−0.6495	0.3935	−0.4485	0.013*

	U11	U22	U33	U12	U13	U23
Mg1	0.0064 (4)	0.0077 (4)	0.0058 (4)	0.0022 (3)	0.0028 (3)	0.0028 (3)
Mg2	0.0120 (5)	0.0086 (5)	0.0095 (5)	0.0035 (4)	0.0061 (4)	0.0034 (4)
Mg3	0.0091 (4)	0.0083 (4)	0.0076 (4)	0.0021 (3)	0.0037 (3)	0.0029 (3)
Mg4	0.0093 (4)	0.0082 (4)	0.0104 (4)	0.0027 (3)	0.0047 (3)	0.0031 (3)
P1	0.0055 (3)	0.0055 (3)	0.0056 (3)	0.0011 (2)	0.0024 (2)	0.0016 (2)
P2	0.0045 (3)	0.0052 (3)	0.0047 (3)	0.0017 (2)	0.0019 (2)	0.0020 (2)
P3	0.0058 (3)	0.0073 (3)	0.0067 (3)	0.0019 (2)	0.0023 (2)	0.0025 (2)
O1	0.0056 (7)	0.0103 (8)	0.0084 (8)	0.0024 (6)	0.0019 (6)	0.0041 (6)
O2	0.0086 (7)	0.0070 (7)	0.0056 (7)	0.0010 (6)	0.0031 (6)	0.0008 (6)
O3	0.0056 (7)	0.0078 (7)	0.0088 (7)	−0.0002 (6)	0.0037 (6)	0.0019 (6)
O4	0.0133 (8)	0.0067 (7)	0.0085 (8)	0.0025 (6)	0.0057 (6)	0.0030 (6)
O5	0.0053 (7)	0.0094 (7)	0.0068 (7)	0.0034 (6)	0.0024 (6)	0.0034 (6)
O6	0.0097 (7)	0.0081 (7)	0.0053 (7)	0.0036 (6)	0.0035 (6)	0.0030 (6)
O7	0.0119 (8)	0.0060 (7)	0.0109 (8)	0.0038 (6)	0.0050 (6)	0.0021 (6)
O8	0.0049 (7)	0.0071 (7)	0.0091 (7)	0.0010 (6)	0.0037 (6)	0.0020 (6)
O9	0.0085 (8)	0.0157 (8)	0.0086 (8)	0.0059 (6)	0.0030 (6)	0.0052 (6)
O10	0.0117 (8)	0.0093 (8)	0.0087 (8)	−0.0002 (6)	0.0018 (6)	0.0048 (6)
O11	0.0098 (7)	0.0073 (7)	0.0102 (8)	0.0014 (6)	0.0025 (6)	0.0025 (6)
O12	0.0084 (8)	0.0137 (8)	0.0099 (8)	0.0037 (6)	0.0042 (6)	0.0010 (6)

Mg1—O10i	2.0235 (17)	P1—O2	1.5431 (16)
Mg1—O5ii	2.0462 (17)	P1—O4	1.5718 (16)
Mg1—O5iii	2.0643 (17)	P2—O5	1.5237 (16)
Mg1—O8	2.0698 (17)	P2—O6	1.5350 (16)
Mg1—O2ii	2.1093 (17)	P2—O8	1.5362 (16)
Mg1—O3iii	2.2065 (17)	P2—O7	1.5533 (16)
Mg2—O7iv	2.0630 (16)	P3—O10	1.5131 (16)
Mg2—O7ii	2.0630 (16)	P3—O11	1.5245 (17)
Mg2—O2	2.1296 (15)	P3—O9	1.5287 (16)
Mg2—O2v	2.1296 (15)	P3—O12	1.5853 (17)
Mg2—O11vi	2.2395 (16)	O2—Mg1ii	2.1093 (17)
Mg2—O11vii	2.2395 (16)	O3—Mg4x	2.0549 (17)
Mg3—O4viii	2.0415 (17)	O3—Mg1x	2.2065 (17)
Mg3—O1	2.0443 (17)	O4—Mg3viii	2.0415 (17)
Mg3—O6	2.0606 (17)	O4—H4	0.8601
Mg3—O6ix	2.0649 (17)	O5—Mg1ii	2.0462 (17)
Mg3—O12x	2.0759 (17)	O5—Mg1x	2.0643 (17)
Mg3—O9	2.0954 (17)	O6—Mg3ix	2.0649 (17)
Mg4—O8	2.0041 (17)	O7—Mg2xi	2.0630 (16)
Mg4—O11vi	2.0426 (18)	O10—Mg1i	2.0235 (17)
Mg4—O9	2.0544 (17)	O11—Mg4vi	2.0426 (18)
Mg4—O3iii	2.0549 (17)	O11—Mg2xii	2.2395 (16)
Mg4—O1	2.1312 (17)	O12—Mg3iii	2.0759 (17)
P1—O3	1.5252 (16)	O12—H12	0.8600
P1—O1	1.5297 (16)
O10i—Mg1—O5ii	177.45 (7)	O1—Mg3—O12x	90.91 (7)
O10i—Mg1—O5iii	93.60 (7)	O6—Mg3—O12x	95.01 (7)
O5ii—Mg1—O5iii	84.54 (7)	O6ix—Mg3—O12x	82.93 (7)
O10i—Mg1—O8	89.62 (7)	O4viii—Mg3—O9	82.41 (7)
O5ii—Mg1—O8	91.62 (7)	O1—Mg3—O9	80.21 (7)
O5iii—Mg1—O8	161.77 (7)	O6—Mg3—O9	96.14 (7)
O10i—Mg1—O2ii	97.16 (7)	O6ix—Mg3—O9	108.15 (7)
O5ii—Mg1—O2ii	84.67 (7)	O12x—Mg3—O9	165.63 (8)
O5iii—Mg1—O2ii	92.32 (7)	O8—Mg4—O11vi	135.86 (7)
O8—Mg1—O2ii	105.09 (7)	O8—Mg4—O9	97.00 (7)
O10i—Mg1—O3iii	96.93 (7)	O11vi—Mg4—O9	124.27 (7)
O5ii—Mg1—O3iii	81.15 (6)	O8—Mg4—O3iii	83.43 (7)
O5iii—Mg1—O3iii	83.53 (6)	O11vi—Mg4—O3iii	102.94 (7)
O8—Mg1—O3iii	78.27 (6)	O9—Mg4—O3iii	98.66 (7)
O2ii—Mg1—O3iii	165.53 (7)	O8—Mg4—O1	88.96 (7)
O7iv—Mg2—O7ii	180.00 (7)	O11vi—Mg4—O1	84.69 (7)
O7iv—Mg2—O2	91.18 (6)	O9—Mg4—O1	79.14 (7)
O7ii—Mg2—O2	88.82 (6)	O3iii—Mg4—O1	171.78 (7)
O7iv—Mg2—O2v	88.82 (6)	O3—P1—O1	111.79 (9)
O7ii—Mg2—O2v	91.18 (6)	O3—P1—O2	114.92 (9)
O2—Mg2—O2v	180.00 (7)	O1—P1—O2	110.31 (9)
O7iv—Mg2—O11vi	90.17 (6)	O3—P1—O4	106.96 (9)
O7ii—Mg2—O11vi	89.83 (6)	O1—P1—O4	107.87 (9)
O2—Mg2—O11vi	85.85 (6)	O2—P1—O4	104.43 (9)
O2v—Mg2—O11vi	94.15 (6)	O5—P2—O6	109.03 (9)
O7iv—Mg2—O11vii	89.83 (6)	O5—P2—O8	111.40 (9)
O7ii—Mg2—O11vii	90.17 (6)	O6—P2—O8	109.62 (9)
O2—Mg2—O11vii	94.15 (6)	O5—P2—O7	109.95 (9)
O2v—Mg2—O11vii	85.85 (6)	O6—P2—O7	108.49 (9)
O11vi—Mg2—O11vii	180.00 (8)	O8—P2—O7	108.30 (9)
O4viii—Mg3—O1	104.92 (7)	O10—P3—O11	112.06 (9)
O4viii—Mg3—O6	165.27 (8)	O10—P3—O9	112.08 (9)
O1—Mg3—O6	89.19 (7)	O11—P3—O9	111.85 (9)
O4viii—Mg3—O6ix	87.80 (7)	O10—P3—O12	107.28 (9)
O1—Mg3—O6ix	165.83 (8)	O11—P3—O12	109.21 (9)
O6—Mg3—O6ix	78.70 (7)	O9—P3—O12	103.90 (9)
O4viii—Mg3—O12x	89.06 (7)

D—H···A	D—H	H···A	D···A	D—H···A
O4—H4···O7iv	0.86	1.61	2.460 (2)	172.
O12—H12···O10i	0.86	1.80	2.656 (2)	171.

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O4—H4⋯O7i	0.86	1.61	2.460 (2)	172
O12—H12⋯O10ii	0.86	1.80	2.656 (2)	171

Symmetry codes: (i) ; (ii) .