Bis[bis(1H-imidazole-κN 3)silver(I)] naphthalene-1,5-disulfonate

The title compound, [Ag(C3H4N2)2]2(C10H6O6S2), exists in the form of isolated cations and anions with electrostatic interaction between them. The Ag atom is two-coordinated by the N atoms of two crystallographically independent imidazole molecules. The naphthalene-1,5-disulfonate anion is located on a crystallographic center of symmetry. The cations and anions are connected through intermolecular N—H⋯O hydrogen bonds.

The title compound, [Ag(C 3 H 4 N 2 ) 2 ] 2 (C 10 H 6 O 6 S 2 ), exists in the form of isolated cations and anions with electrostatic interaction between them. The Ag atom is two-coordinated by the N atoms of two crystallographically independent imidazole molecules. The naphthalene-1,5-disulfonate anion is located on a crystallographic center of symmetry. The cations and anions are connected through intermolecular N-HÁ Á ÁO hydrogen bonds.
We thank the Henan Institute of Science and Technology for financial support and we thank Professor Ji-Wen Cai for his guidance.
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: RK2068).

Comment
In the part of our recent investigations into the development of mixed inorganic-organic hybrid materials, we synthesized the silver sulfonate compound, which can be possess a potential wide chemical opportunity.
Sulfonate compounds have received much attention due to their potential application in chemical absorption and separation Zhou et al., 2004;Liu et al., 2006). However, the weak coordination nature of SO 3 -group makes its coordination mode very flexible and sensitive to the chemical environment (Côté et al., 2003). Likewise, Ag + ion is a notoriously pliant with respect to its coordination sphere. Thus, in silver sulfonates, various coordination modes are observed with coordination number ranging from two to nine (Côté et al., 2004;Dalrymple et al., 2002;Reddy et al., 2003;Shimizu et al., 1999). On the other hand, the coordination behavior of arene-sulfonates with transition metals can be peculiar in the presence of amino ligands Cai et al., 2001;Chen et al., 2002).

Experimental
Disodium 1,5-naphthalene-disulfonate (0.33 g, 1 mmol) and imidazole (0.27 g, 4 mmol) were added to an aqueous solution of AgNO 3 (0.32 g, 2 mmol) (10 ml). The result solution was stirred at 343 K for four hours in a water bath. After filtration, a clear solution was set aside to crystallize.