Received 6 March 2009
The title compound, [Zn(C2H8NO6P2)2(H2O)4]·4H2O, was synthesized by the reaction of ZnCl2 with 1-aminoethane-1,1-diyldiphosphonic acid in aqueous solution. The asymmetric unit contains one-half of the complex and two water molecules of solvation. The Zn atom occupies a special position on an inversion centre. This results in a slightly distorted octahedral coordination environment, which consists of the O atoms from two phosphonic acids and four water molecules. The crystal structure displays N-HO and O-HO hydrogen bonding, which creates a three-dimensional network.
Diphosphonic acids are efficient drugs for the prevention of calcification and the inhibition of bone resorption, see: Matczak-Jon & Videnova-Adrabinska (2005). Diphosphonic acids and their metal complexes are used in the treatment of Pagets disease, osteoporosis and tumoral osteolysis, see: Szabo et al. (2002). For related structures, see: Li et al. (2006, 2007); Lin et al. (2007).
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: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: publCIF (Westrip, 2009).
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: FJ2201 ).
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Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.
Szabo, Ch. M., Martin, M. B. & Oldfield, E. (2002). J. Med. Chem. 45, 2894-2903.
Westrip, S. P. (2009). publCIF. In preparation.