Disodium nickel bis­(sulfate) tetra­hydrate: a nickel astrakanite

The title compound, [Na₂Ni(SO₄)₂(H₂O)₄] or Ni astrakanite, is part of an isostructural family containing the Mg (the original astrakanite mineral), Zn and Co species. The very regular NiO(H₂O)₄O(SO₄)₂ octa­hedra lie at centers of symmetry, while the rather distorted NaO(H₂O)₂O(SO₄)₄ octa­hedra are at general positions, linked into a three-dimensional network by the bridging water mol­ecules and fully coordinated sulfate groups.

Key indicators

• Single-crystal X-ray study
• T = 294 K
• Mean [sigma](S-O) = 0.002 Å
• R factor = 0.023
• wR factor = 0.067
• Data-to-parameter ratio = 11.5

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT042_ALERT_1_C Calc. and Rep. MoietyFormula Strings Differ ....          ?
PLAT720_ALERT_4_C Number of Unusual/Non-Standard Label(s) ........          4
PLAT779_ALERT_2_C Suspect or Irrelevant (Bond) Angle in CIF ......      39.34 Deg.
              O2   -S1   -NA1     1.555   1.555   4.565

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   3 ALERT level C = Check and explain
   0 ALERT level G = General alerts; check

   1 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   1 ALERT type 2 Indicator that the structure model may be wrong or deficient
   0 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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Computing details

Data collection: SMART (Bruker, 2001); cell refinement: SAINT (Bruker, 2001); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Bruker, 2001); software used to prepare material for publication: SHELXTL and PLATON (Spek, 2005).

Disodium nickel bis(sulfate) tetrahydrate

Crystal data

[Na2Ni(SO4)2(H2O)4]	F(000) = 372
Mr = 368.87	Dx = 2.494 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 3942 reflections
a = 5.5284 (6) Å	θ = 3.1–27.8°
b = 8.189 (1) Å	µ = 2.55 mm^−1
c = 11.0343 (13) Å	T = 294 K
β = 100.468 (2)°	Plates, light_blue
V = 491.23 (10) Å^3	0.22 × 0.16 × 0.08 mm
Z = 2

Data collection

Bruker SMART CCD diffractometer	1094 independent reflections
Radiation source: fine-focus sealed tube	1060 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.016
φ and ω scans	θmax = 27.8°, θmin = 3.1°
Absorption correction: multi-scan (SADABS; Sheldrick, 2001)	h = −7→7
Tmin = 0.604, Tmax = 0.822	k = −10→10
3942 measured reflections	l = −14→14

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.023	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.067	H atoms treated by a mixture of independent and constrained refinement
S = 1.03	w = 1/[σ^2(Fo^2) + (0.0476P)^2 + 0.2019P] where P = (Fo^2 + 2Fc^2)/3
1094 reflections	(Δ/σ)max = 0.001
95 parameters	Δρmax = 0.39 e Å^−3
6 restraints	Δρmin = −0.33 e Å^−3

Special details

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Ni1	0.0000	0.0000	0.0000	0.01453 (13)
Na1	0.12865 (15)	0.06926 (10)	0.36180 (7)	0.0239 (2)
S1	0.37008 (8)	0.28638 (5)	0.13650 (4)	0.01497 (14)
O1	0.3493 (3)	0.26831 (18)	0.26754 (13)	0.0241 (3)
O2	0.2051 (3)	0.41431 (18)	0.07920 (13)	0.0248 (3)
O3	0.3146 (3)	0.12945 (18)	0.07142 (14)	0.0233 (3)
O4	0.6288 (3)	0.32744 (18)	0.13104 (14)	0.0245 (3)
O1W	−0.1253 (3)	0.03655 (19)	0.16071 (13)	0.0195 (3)
O2W	0.1722 (3)	−0.20991 (17)	0.08071 (13)	0.0202 (3)
H1WA	−0.221 (4)	−0.039 (2)	0.174 (3)	0.037 (8)*
H1WB	−0.210 (4)	0.1225 (19)	0.151 (3)	0.039 (8)*
H2WA	0.299 (3)	−0.207 (4)	0.1364 (19)	0.043 (8)*
H2WB	0.208 (5)	−0.277 (3)	0.028 (2)	0.057 (10)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Ni1	0.0153 (2)	0.0141 (2)	0.01415 (19)	−0.00007 (11)	0.00272 (13)	−0.00081 (11)
Na1	0.0263 (4)	0.0237 (4)	0.0213 (4)	−0.0011 (3)	0.0032 (3)	0.0013 (3)
S1	0.0143 (2)	0.0152 (2)	0.0152 (2)	0.00061 (16)	0.00202 (17)	−0.00081 (15)
O1	0.0302 (8)	0.0254 (8)	0.0171 (7)	0.0019 (6)	0.0056 (6)	0.0018 (5)
O2	0.0275 (8)	0.0253 (8)	0.0211 (7)	0.0104 (6)	0.0025 (6)	0.0027 (5)
O3	0.0189 (7)	0.0215 (7)	0.0291 (8)	−0.0028 (5)	0.0031 (6)	−0.0095 (6)
O4	0.0178 (7)	0.0217 (7)	0.0350 (8)	−0.0035 (6)	0.0074 (6)	−0.0032 (6)
O1W	0.0201 (7)	0.0198 (7)	0.0194 (7)	0.0005 (6)	0.0059 (5)	0.0000 (6)
O2W	0.0202 (7)	0.0181 (7)	0.0201 (7)	0.0021 (5)	−0.0018 (5)	−0.0011 (5)

Geometric parameters (Å, º)

Ni1—O1W	2.0399 (14)	Na1—O2^iv	2.4237 (16)
Ni1—O1W^i	2.0399 (14)	Na1—O2W^v	2.6120 (17)
Ni1—O3	2.0669 (14)	S1—O2	1.4560 (15)
Ni1—O3^i	2.0669 (14)	S1—O3	1.4769 (14)
Ni1—O2W^i	2.0848 (14)	S1—O1	1.4787 (14)
Ni1—O2W	2.0848 (14)	S1—O4	1.4812 (15)
Na1—O2^ii	2.3627 (16)	O1W—H1WA	0.841 (10)
Na1—O4^iii	2.3848 (16)	O1W—H1WB	0.842 (10)
Na1—O1	2.3848 (17)	O2W—H2WA	0.844 (10)
Na1—O1W	2.4155 (16)	O2W—H2WB	0.846 (10)
O1W—Ni1—O1W^i	180.00 (8)	O2^iv—Na1—O2W^v	75.39 (5)
O1W—Ni1—O3	89.34 (6)	O2—S1—O3	110.89 (9)
O1W^i—Ni1—O3	90.66 (6)	O2—S1—O1	110.04 (9)
O1W—Ni1—O3^i	90.66 (6)	O3—S1—O1	110.01 (9)
O1W^i—Ni1—O3^i	89.34 (6)	O2—S1—O4	110.64 (9)
O3—Ni1—O3^i	180.00 (10)	O3—S1—O4	107.13 (8)
O1W—Ni1—O2W^i	92.84 (6)	O1—S1—O4	108.05 (9)
O1W^i—Ni1—O2W^i	87.16 (6)	O2—S1—Na1^vi	39.34 (6)
O3—Ni1—O2W^i	91.57 (6)	O3—S1—Na1^vi	81.46 (6)
O3^i—Ni1—O2W^i	88.43 (6)	O1—S1—Na1^vi	147.51 (7)
O1W—Ni1—O2W	87.16 (6)	O4—S1—Na1^vi	96.53 (6)
O1W^i—Ni1—O2W	92.84 (6)	S1—O1—Na1	129.18 (9)
O3—Ni1—O2W	88.43 (6)	S1—O2—Na1^vi	117.66 (8)
O3^i—Ni1—O2W	91.57 (6)	S1—O2—Na1^v	135.03 (9)
O2W^i—Ni1—O2W	180.00 (8)	Na1^vi—O2—Na1^v	103.80 (6)
O2^ii—Na1—O4^iii	91.03 (6)	S1—O3—Ni1	135.86 (9)
O2^ii—Na1—O1	113.12 (6)	S1—O4—Na1^vii	136.76 (9)
O4^iii—Na1—O1	104.66 (6)	Ni1—O1W—Na1	125.61 (7)
O2^ii—Na1—O1W	154.93 (6)	Ni1—O1W—H1WA	112 (2)
O4^iii—Na1—O1W	99.66 (6)	Na1—O1W—H1WA	101 (2)
O1—Na1—O1W	86.17 (6)	Ni1—O1W—H1WB	106 (2)
O2^ii—Na1—O2^iv	76.20 (6)	Na1—O1W—H1WB	104 (2)
O4^iii—Na1—O2^iv	90.41 (6)	H1WA—O1W—H1WB	106.3 (15)
O1—Na1—O2^iv	161.73 (6)	Ni1—O2W—Na1^iv	114.40 (6)
O1W—Na1—O2^iv	81.08 (5)	Ni1—O2W—H2WA	123 (2)
O2^ii—Na1—O2W^v	73.64 (5)	Na1^iv—O2W—H2WA	109 (2)
O4^iii—Na1—O2W^v	161.06 (6)	Ni1—O2W—H2WB	113 (2)
O1—Na1—O2W^v	91.80 (5)	Na1^iv—O2W—H2WB	88 (2)
O1W—Na1—O2W^v	90.59 (5)	H2WA—O2W—H2WB	104.7 (15)

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1W—H1WB···O4^viii	0.84 (1)	1.89 (1)	2.733 (2)	174 (3)
O1W—H1WA···O1^iv	0.84 (1)	1.89 (1)	2.709 (2)	163 (3)
O2W—H2WA···O1^iii	0.84 (1)	2.05 (1)	2.868 (2)	163 (2)
O2W—H2WB···O4^ix	0.85 (1)	2.16 (2)	2.921 (2)	150 (3)

Symmetry codes: (iii) −x+1, y−1/2, −z+1/2; (iv) −x, y−1/2, −z+1/2; (viii) x−1, y, z; (ix) −x+1, −y, −z.