Smith Graham, Wermuth Urs D
Science and Engineering Faculty, Queensland University of Technology, GPO Box 2434, Brisbane, Queensland 4001, Australia.
Acta Crystallogr C. 2013 May;69(Pt 5):534-7. doi: 10.1107/S0108270113008846. Epub 2013 Apr 11.
The structures of two ammonium salts of 3-carboxy-4-hydroxybenzenesulfonic acid (5-sulfosalicylic acid, 5-SSA) have been determined at 200 K. In the 1:1 hydrated salt, ammonium 3-carboxy-4-hydroxybenzenesulfonate monohydrate, NH4(+)·C7H5O6S(-)·H2O, (I), the 5-SSA(-) monoanions give two types of head-to-tail laterally linked cyclic hydrogen-bonding associations, both with graph-set R4(4)(20). The first involves both carboxylic acid O-H···O(water) and water O-H···O(sulfonate) hydrogen bonds at one end, and ammonium N-H···O(sulfonate) and N-H···O(carboxy) hydrogen bonds at the other. The second association is centrosymmetric, with end linkages through water O-H···O(sulfonate) hydrogen bonds. These conjoined units form stacks down c and are extended into a three-dimensional framework structure through N-H···O and water O-H···O hydrogen bonds to sulfonate O-atom acceptors. Anhydrous triammonium 3-carboxy-4-hydroxybenzenesulfonate 3-carboxylato-4-hydroxybenzenesulfonate, 3NH4(+)·C7H4O6S(2-)·C7H5O6S(-), (II), is unusual, having both dianionic 5-SSA(2-) and monoanionic 5-SSA(-) species. These are linked by a carboxylic acid O-H···O hydrogen bond and, together with the three ammonium cations (two on general sites and the third comprising two independent half-cations lying on crystallographic twofold rotation axes), give a pseudo-centrosymmetric asymmetric unit. Cation-anion hydrogen bonding within this layered unit involves a cyclic R3(3)(8) association which, together with extensive peripheral N-H···O hydrogen bonding involving both sulfonate and carboxy/carboxylate acceptors, gives a three-dimensional framework structure. This work further demonstrates the utility of the 5-SSA(-) monoanion for the generation of stable hydrogen-bonded crystalline materials, and provides the structure of a dianionic 5-SSA(2-) species of which there are only a few examples in the crystallographic literature.
已在200 K下测定了3-羧基-4-羟基苯磺酸（5-磺基水杨酸，5-SSA）两种铵盐的结构。在1:1水合盐3-羧基-4-羟基苯磺酸铵一水合物NH₄⁺·C₇H₅O₆S⁻·H₂O（I）中，5-SSA⁻单阴离子形成两种头对头侧向连接的环状氢键缔合，均为R₄⁴(20)图式。第一种在一端涉及羧酸O—H···O（水）和水O—H···O（磺酸根）氢键，在另一端涉及铵N—H···O（磺酸根）和N—H···O（羧基）氢键。第二种缔合是中心对称的，通过水O—H···O（磺酸根）氢键进行末端连接。这些相连的单元沿c轴形成堆积，并通过N—H···O和水O—H···O氢键与磺酸根O原子受体扩展成三维骨架结构。无水三铵3-羧基-4-羟基苯磺酸盐3-羧基-4-羟基苯磺酸盐3NH₄⁺·C₇H₄O₆S²⁻·C₇H₅O₆S⁻（II）很不寻常，含有双阴离子5-SSA²⁻和单阴离子5-SSA⁻物种。它们通过羧酸O—H···O氢键相连，与三个铵阳离子（两个在一般位置，第三个由位于晶体学二重旋转轴上的两个独立半阳离子组成）一起构成一个假中心对称的不对称单元。该层状单元内的阳离子-阴离子氢键涉及一个环状R₃³(8)缔合，与涉及磺酸根和羧基/羧酸盐受体的广泛外围N—H···O氢键一起，形成三维骨架结构。这项工作进一步证明了5-SSA⁻单阴离子在生成稳定氢键晶体材料方面的效用，并提供了双阴离子5-SSA²⁻物种的结构，此类结构在晶体学文献中仅有少数例子。
