Chemey Alexander T, McGuire Chad M, Albrecht-Schmitt Thomas E
Department of Chemistry and Biochemistry, Florida State University, 95 Chieftan Way Tallahassee, FL 32306, USA.
Acta Crystallogr E Crystallogr Commun. 2018 May 18;74(Pt 6):820-824. doi: 10.1107/S2056989018006916. eCollection 2018 Jun 1.
The title compound {systematic name: 3-carb-oxy-2-[2-(3-carb-oxy-pyridin-2-yl)disulfan-1-yl)]pyridin-1-ium chloride monohydrate}, CHNOS·Cl·HO, crystallizes in the triclinic space group . A pair of 2-mercaptonicotinic acid moieties is connected by a 2,2'-di-sulfide bond with a dihedral angle of 78.79 (3)°. One of the N atom is protonated, as are both carboxyl-ate groups, resulting in an overall +1 charge on the dimer. The structure comprises a zigzagging layer of the dimerized di-thio-dinicotinic acid rings, with charge-balancing chloride ions and water mol-ecules between the layers. Hydrogen bonding between the chloride and water sites with the dimer appears to hold the structure together. Nearest neighbor nicotinic acid rings are offset when viewed down the axis, suggesting no added stability from ring stacking. The asymmetric unit corresponds to the empirical formula of the compound, and it packs with two formula units per unit cell.
标题化合物{系统名称：3 - 羧基 - 2 - [2 - (3 - 羧基吡啶 - 2 - 基)二硫烷 - 1 - 基]吡啶 - 1 - 鎓氯化物一水合物}，CHNOS·Cl·HO，结晶于三斜空间群 。一对2 - 巯基烟酸部分通过2,2'-二硫键相连，二面角为78.79 (3)°。其中一个N原子质子化，两个羧酸根基团也质子化，导致二聚体整体带 +1电荷。结构由二聚化的二硫代二烟酸环的锯齿状层组成，层间有电荷平衡的氯离子和水分子。氯离子和水分子与二聚体之间的氢键似乎使结构保持在一起。沿 轴向下看时，最近邻的烟酸环相互错开，表明环堆积没有增加稳定性。不对称单元对应于化合物的经验式，每个晶胞以两个化学式单元堆积。
