(IUCr) Disodium zinc bis(sulfate) tetrahydrate (zinc astrakanite) revisited

Volume 64
Part 6
Pages i30-i31
June 2008

Received 7 March 2008
Accepted 8 April 2008
Online 7 May 2008

Key indicators
Single-crystal X-ray study
T = 170 K
Mean (S-O) = 0.001 Å
R = 0.018
wR = 0.055
Data-to-parameter ratio = 11.2
Details

Disodium zinc bis(sulfate) tetrahydrate (zinc astrakanite) revisited

M. Enriqueta Díaz de Vivar,^a ^* Sergio Baggio,^a Andrés Ibáñez ^b and Ricardo Baggio ^c

^aUniversidad Nacional de la Patagonia, Sede Puerto Madryn, and CenPat, CONICET, 9120 Puerto Madryn, Chubut, Argentina,^bDepartamento de Física, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, and CIMAT, Casilla 487-3, Santiago de Chile, Chile, and ^cDepartamento de Física, Comisión Nacional de Energía Atómica, Buenos Aires, Argentina
Correspondence e-mail: undiaz@cenpat.edu.ar

We present a new low-temperature refinement of disodium zinc bis(sulfate) tetrahydrate {systematic name: poly[tetra- [mu] -aqua-di- [mu] -sulfato-zinc(II)disodium(I)]}, [Na₂Zn(SO₄)₂(H₂O)₄]_n or Zn astrakanite, which is an upgrade of previously reported data [Bukin & Nozik (1974). Zh. Strukt. Khim. 15, 712-716]. The compound is part of an isostructural family containing the Mg (the original astrakanite mineral), Co and Ni species. The very regular ZnO(aqua)₄O(sulfate)₂ octahedra lie on centres of symmetry, while the rather distorted NaO(aqua)₂O(sulfate)₄ octahedra appear at general positions, linked into a three-dimensional network by the bridging water molecules and the fully coordinated sulfate groups.

Related literature

For related literature, see: Rumanova (1958); Giglio (1958); Bukin & Nozik (1974, 1975); Díaz de Vivar et al. (2006).

Experimental

Crystal data

[Na₂Zn(SO₄)₂(H₂O)₄]
M_r = 375.53
Monoclinic, P 2₁ /c
a = 5.5075 (2) Å
b = 8.2127 (3) Å
c = 11.0559 (4) Å
= 99.958 (10)°
V = 492.54 (3) Å³
Z = 2
Mo K radiation
= 3.07 mm^-1
T = 170 (2) K
0.30 × 0.20 × 0.10 mm

Data collection

Bruker SMART CCD diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) T_min = 0.452, T_max = 0.728
3533 measured reflections
1080 independent reflections
1062 reflections with I > 2(I)
R_int = 0.012

Refinement

R[F² > 2(F²)] = 0.017
wR(F²) = 0.054
S = 1.00
1080 reflections
96 parameters
6 restraints
H atoms treated by a mixture of independent and constrained refinement
_max = 0.29 e Å^-3
_min = -0.53 e Å^-3

Table 1
Selected bond lengths (Å)

Zn1-O1W	2.0636 (11)
Zn1-O3	2.0952 (11)
Zn1-O2W	2.1285 (11)
Na1-O2ⁱ	2.3603 (12)
Na1-O4ⁱⁱ	2.3786 (12)
Na1-O1	2.4016 (12)
Na1-O1W	2.4017 (12)
Na1-O2ⁱⁱⁱ	2.4224 (13)
Na1-O2W^iv	2.5694 (13)
Symmetry codes: (i) $[x, -y+{\script{1\over 2}}, z+{\script{1\over 2}}]$ ; (ii) $[-x+1, y-{\script{1\over 2}}, -z+{\script{1\over 2}}]$ ; (iii) $[-x, y-{\script{1\over 2}}, -z+{\script{1\over 2}}]$ ; (iv) $[-x, y+{\script{1\over 2}}, -z+{\script{1\over 2}}]$ .

Table 2
Hydrogen-bond geometry (Å, °)

D-HA	D-H	HA	DA	D-HA
O1W-H1WAO1ⁱⁱⁱ	0.800 (17)	1.916 (17)	2.6977 (17)	165 (3)
O1W-H1WBO4^v	0.832 (16)	1.901 (16)	2.7288 (17)	173 (2)
O2W-H2WAO1ⁱⁱ	0.826 (16)	2.051 (18)	2.8468 (16)	162 (2)
O2W-H2WBO4^vi	0.805 (16)	2.15 (2)	2.8779 (16)	151 (3)
Symmetry codes: (ii) $[-x+1, y-{\script{1\over 2}}, -z+{\script{1\over 2}}]$ ; (iii) $[-x, y-{\script{1\over 2}}, -z+{\script{1\over 2}}]$ ; (v) x-1, y, z; (vi) -x+1, -y, -z.

Data collection: SMART (Bruker, 2001); cell refinement: SAINT (Bruker, 2001); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL and PLATON (Spek, 2003).

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: FI2061 ).

Acknowledgements

The authors acknowledge the Spanish Research Council (CSIC) for providing a free-of-charge licence to the Cambridge Structural Database (Allen, 2002).

References

Allen, F. H. (2002). Acta Cryst. B58, 380-388.
Bruker (2001). SMART and SAINT for Windows NT. Bruker AXS Inc., Madison, Wisconsin, USA.
Bukin, V. I. & Nozik, Yu. Z. (1974). Zh. Strukt. Khim. 15, 712-716.
Bukin, V. I. & Nozik, Yu. Z. (1975). Kristallografiya, 20, 293-296.
Díaz de Vivar, M. E. de, Baggio, S., Garland, M. T. & Baggio, R. (2006). Acta Cryst. E62, i196-i198.
Giglio, M. (1958). Naturwissenschaften, 45, 82-83.
Rumanova, I. M. (1958). Dokl. Akad. Nauk SSSR, 118, 84-87.
Sheldrick, G. M. (1996). SADABS. University of Göttingen, Germany.
Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.
Spek, A. L. (2003). J. Appl. Cryst. 36, 7-13.

inorganic compounds