(4-Amino-3-methylbenzenesulfonato)tri-μ-aqua-pentaaquadisodium 4-amino-3-methylbenzenesulfonate

In the title compound, [Na2(C7H8NO3S)(H2O)8](C7H8NO3S), one Na+ ion is bonded to six water molecules in a distorted octahedral arrangement while the other is bonded to five water molecules and one O atom of a 4-amino-3-methylbenzenesulfonate anion, also yielding a distorted NaO6 octahedron. Three of the water molecules bridge the metal ions and an intramolecular O—H⋯O hydrogen bond helps to establish the conformation. In the crystal, the component species interact by way of O—H⋯O, O—H⋯N and N—H⋯O hydrogen bonds.

In the title compound, [Na 2 (C 7 H 8 NO 3 S)(H 2 O) 8 ](C 7 H 8 NO 3 S), one Na + ion is bonded to six water molecules in a distorted octahedral arrangement while the other is bonded to five water molecules and one O atom of a 4-amino-3-methylbenzenesulfonate anion, also yielding a distorted NaO 6 octahedron. Three of the water molecules bridge the metal ions and an intramolecular O-HÁ Á ÁO hydrogen bond helps to establish the conformation. In the crystal, the component species interact by way of O-HÁ Á ÁO, O-HÁ Á ÁN and N-HÁ Á ÁO hydrogen bonds.
This project was supported by the National Natural Science Foundation of China (20671073), the Natural Science Foundation of Shandong (Y2007B60) and the Science Foundation of Weifang University.
(4-Amino-3-methylbenzenesulfonato)tri--aqua-pentaaquadisodium 4-amino-3-methylbenzenesulfonate X.-S. Tai and F.-G. Zhang Comment During the past two decades, the design and synthesis of organic-inorganic hybrid materials have attracted intense attentions owing to their potential practical applications [Wang, et al., 2008;Tai, et al., 2007]. Benzenesulfonic acids can potentially be monodentate, bidentate ligands, they may also be intermolecularly bridging or intramolecularly chelating ligands. As part of our ongoing study in this field, In this paper, we report on the synthesis and crystal structure of the title compound, (I), (Scheme I).
In the crystal of (I), Na1 atom is six coordinate to five water molecules and one ligand, and Na2 atom is six coordinate to water molecules. The bond distances of Na-O are in the range of 2.341 (3)-2.670 (3). Otherwise, the geometrical parameters for (I) are normal. In the crystal packing, the molecules form a thrre-dimensional network by hydrogen bonds.

Experimental
A solution of 1.0 mmol NaOH in 1 ml water was added to a solution of 1.0 mmol 4-amino-3-methyl-benzenesulfonic acid in 5 ml ethanol at room temperature. The mixture was refluxed for 4 h with stirring, then the resulting precipitate was filtered, washed, and dried in vacuo over P 4 O 10 for 48 h. Colourless blocks of (I) were obtained by slowly evaporating from methanol at room temperature. Fig. 1. The molecular structure of (I) showing 30% displacement ellipsoids.