Hexa-aqua-nickel(II) di-hydrogen hypodiphosphate.

The asymmetric unit of the title compound, [Ni(H2O)6](H2P2O6), contains one-half of the hexa-aqua-nickel(II) cation and one-half of the di-hydrogen hypodiphosphate anion. In the complex cation, the Ni(2+) atom is located on an inversion center and has an octa-hedral coordination sphere. The P-P distance in the centrosymmetric anion is 2.1853 (7) Å. In the crystal, discrete [Ni(H2O)6](2+) cations and (H2P2O6)(2-) anions are stacked in columns parallel to the c axis and are linked into a three-dimensional network by medium-strength O-H⋯O hydrogen bonds.

Related literature

For the synthesis of hypodiphosphates, see: Leininger & Chulski (1953 ▶). For applications of hypodiphosphates, see: Bloss & Henzel (1967 ▶); Ruflin et al. (2007 ▶); Szklarz et al. (2011 ▶). For the crystal structures of transition metal hypodiphosphate 12-hydrates, see: Hagen & Jansen (1995 ▶); Haag et al. (2005 ▶). For the crystal structures of hydrogen hypodiphosphate compounds, see: Collin & Willis (1971 ▶); Szafranowska et al. (2012 ▶); Wu et al. (2012 ▶).

Experimental

Crystal data

[Ni(H2O)6](H2P2O6)

M = 326.76

Monoclinic,

a = 9.3031 (14) Å

b = 5.8892 (8) Å

c = 9.7620 (12) Å

β = 96.111 (11)°

V = 531.80 (13) Å3

Z = 2

Mo Kα radiation

μ = 2.18 mm−1

T = 223 K

0.29 × 0.25 × 0.22 mm

Data collection

Stoe IPDS-II diffractometer

Absorption correction: numerical (X-SHAPE and X-RED; Stoe & Cie, 1999 ▶, 2001 ▶) T min = 0.537, T max = 0.619

8061 measured reflections

1601 independent reflections

1546 reflections with I > 2σ(I)

R int = 0.056

Refinement

R[F 2 > 2σ(F 2)] = 0.029

wR(F 2) = 0.074

S = 1.16

1601 reflections

98 parameters

All H-atom parameters refined

Δρmax = 0.44 e Å−3

Δρmin = −1.08 e Å−3

Data collection: X-AREA (Stoe & Cie, 2002 ▶); cell refinement: X-AREA; data reduction: X-AREA; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: DIAMOND (Brandenburg, 2012 ▶); software used to prepare material for publication: SHELXL97, PLATON (Spek, 2009 ▶) and publCIF (Westrip, 2010 ▶).

Crystal structure: contains datablock(s) I. DOI: 10.1107/S1600536813030717/wm2784sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536813030717/wm2784Isup2.hkl

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

[Ni(H2O)6](H2P2O6)	F(000) = 336
Mr = 326.76	block, green
Monoclinic, P21/n	Dx = 2.041 Mg m−3
Hall symbol: -P 2yn	Mo Kα radiation, λ = 0.71073 Å
a = 9.3031 (14) Å	Cell parameters from 8465 reflections
b = 5.8892 (8) Å	θ = 2.9–30.5°
c = 9.7620 (12) Å	µ = 2.18 mm−1
β = 96.111 (11)°	T = 223 K
V = 531.80 (13) Å3	Block, green
Z = 2	0.29 × 0.25 × 0.22 mm

Stoe IPDS-II diffractometer	1601 independent reflections
Radiation source: fine-focus sealed tube	1546 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.056
ω–scans	θmax = 30.5°, θmin = 2.9°
Absorption correction: numerical (X-SHAPE and X-RED; Stoe & Cie, 1999, 2001)	h = −13→13
Tmin = 0.537, Tmax = 0.619	k = −8→8
8061 measured reflections	l = −13→13

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)] = 0.029	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.074	All H-atom parameters refined
S = 1.16	w = 1/[σ2(Fo2) + (0.0423P)2 + 0.1511P] where P = (Fo2 + 2Fc2)/3
1601 reflections	(Δ/σ)max = 0.001
98 parameters	Δρmax = 0.44 e Å−3
0 restraints	Δρmin = −1.08 e Å−3

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.

	x	y	z	Uiso*/Ueq
Ni	0.5000	0.5000	0.5000	0.01306 (10)
P	0.06859 (3)	0.14612 (5)	0.53007 (3)	0.01116 (10)
O1	0.20361 (11)	0.05887 (19)	0.61176 (12)	0.0177 (2)
O2	0.08555 (10)	0.28724 (17)	0.40289 (10)	0.01404 (19)
O3	−0.02399 (12)	0.28534 (18)	0.62787 (11)	0.0185 (2)
O4	0.64678 (11)	0.6071 (2)	0.65421 (12)	0.0211 (2)
O5	0.48685 (12)	0.20885 (19)	0.61392 (12)	0.0204 (2)
O6	0.32539 (11)	0.62296 (19)	0.59655 (12)	0.0180 (2)
H3	−0.042 (3)	0.436 (5)	0.605 (3)	0.037 (7)*
H4A	0.620 (3)	0.681 (5)	0.719 (3)	0.037 (7)*
H4B	0.720 (3)	0.664 (5)	0.630 (3)	0.042 (7)*
H5A	0.407 (4)	0.154 (5)	0.607 (3)	0.045 (8)*
H5B	0.521 (3)	0.223 (5)	0.696 (3)	0.039 (7)*
H6A	0.296 (2)	0.750 (4)	0.581 (2)	0.019 (5)*
H6B	0.313 (3)	0.584 (5)	0.678 (3)	0.036 (7)*

	U11	U22	U33	U12	U13	U23
Ni	0.01080 (13)	0.01511 (15)	0.01334 (15)	−0.00152 (7)	0.00159 (9)	−0.00086 (8)
P	0.00991 (15)	0.01073 (17)	0.01287 (17)	−0.00066 (9)	0.00128 (11)	0.00094 (10)
O1	0.0130 (4)	0.0173 (4)	0.0219 (5)	−0.0003 (4)	−0.0026 (4)	0.0023 (4)
O2	0.0140 (4)	0.0134 (4)	0.0151 (5)	−0.0015 (3)	0.0037 (3)	0.0017 (3)
O3	0.0251 (5)	0.0138 (4)	0.0179 (5)	0.0040 (4)	0.0086 (4)	0.0022 (4)
O4	0.0138 (4)	0.0332 (6)	0.0169 (5)	−0.0071 (4)	0.0043 (4)	−0.0090 (4)
O5	0.0194 (5)	0.0207 (5)	0.0204 (5)	−0.0044 (4)	−0.0005 (4)	0.0028 (4)
O6	0.0180 (5)	0.0194 (5)	0.0172 (5)	0.0040 (4)	0.0041 (4)	−0.0003 (4)

Ni—O4	2.0226 (11)	P—O3	1.5814 (11)
Ni—O4i	2.0227 (11)	P—Pii	2.1853 (7)
Ni—O5i	2.0544 (11)	O3—H3	0.92 (3)
Ni—O5	2.0544 (11)	O4—H4A	0.82 (3)
Ni—O6	2.0922 (11)	O4—H4B	0.82 (3)
Ni—O6i	2.0922 (11)	O5—H5A	0.81 (3)
P—O1	1.5048 (10)	O5—H5B	0.84 (3)
P—O1	1.5048 (10)	O6—H6A	0.81 (2)
P—O2	1.5161 (10)	O6—H6B	0.84 (3)
O4—Ni—O4i	180.0	O1—P—O3	109.55 (6)
O4—Ni—O5i	93.91 (5)	O1—P—O3	109.55 (6)
O4i—Ni—O5i	86.09 (5)	O2—P—O3	108.73 (6)
O4—Ni—O5	86.09 (5)	O1—P—Pii	107.70 (5)
O4i—Ni—O5	93.91 (5)	O1—P—Pii	107.70 (5)
O5i—Ni—O5	179.999 (1)	O2—P—Pii	108.69 (5)
O4—Ni—O6	92.97 (5)	O3—P—Pii	103.32 (5)
O4i—Ni—O6	87.03 (5)	O1—O1—P	0 (10)
O5i—Ni—O6	92.80 (5)	P—O3—H3	116.7 (19)
O5—Ni—O6	87.20 (5)	Ni—O4—H4A	119.9 (19)
O4—Ni—O6i	87.03 (5)	Ni—O4—H4B	115 (2)
O4i—Ni—O6i	92.97 (5)	H4A—O4—H4B	109 (3)
O5i—Ni—O6i	87.20 (5)	Ni—O5—H5A	114 (2)
O5—Ni—O6i	92.80 (5)	Ni—O5—H5B	113 (2)
O6—Ni—O6i	180.0	H5A—O5—H5B	112 (3)
O1—P—O1	0.00 (11)	Ni—O6—H6A	119.9 (16)
O1—P—O2	117.86 (6)	Ni—O6—H6B	121.2 (19)
O1—P—O2	117.86 (6)	H6A—O6—H6B	111 (2)

D—H···A	D—H	H···A	D···A	D—H···A
O3—H3···O2iii	0.92 (3)	1.68 (3)	2.5919 (15)	168 (3)
O4—H4A···O3iv	0.82 (3)	1.93 (3)	2.7293 (16)	165 (3)
O4—H4B···O2i	0.82 (3)	1.89 (3)	2.6822 (14)	162 (3)
O5—H5A···O1	0.81 (3)	1.98 (3)	2.7770 (15)	171 (3)
O5—H5B···O2v	0.84 (3)	2.04 (3)	2.8722 (16)	171 (3)
O6—H6A···O1vi	0.81 (2)	2.05 (2)	2.8163 (16)	159 (2)
O6—H6B···O1iv	0.84 (3)	2.08 (3)	2.9132 (17)	168 (3)

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O3—H3⋯O2i	0.92 (3)	1.68 (3)	2.5919 (15)	168 (3)
O4—H4A⋯O3ii	0.82 (3)	1.93 (3)	2.7293 (16)	165 (3)
O4—H4B⋯O2iii	0.82 (3)	1.89 (3)	2.6822 (14)	162 (3)
O5—H5A⋯O1	0.81 (3)	1.98 (3)	2.7770 (15)	171 (3)
O5—H5B⋯O2iv	0.84 (3)	2.04 (3)	2.8722 (16)	171 (3)
O6—H6A⋯O1v	0.81 (2)	2.05 (2)	2.8163 (16)	159 (2)
O6—H6B⋯O1ii	0.84 (3)	2.08 (3)	2.9132 (17)	168 (3)

Symmetry codes: (i) ; (ii) ; (iii) ; (iv) ; (v) .