Shaibah Mohammed A E, Sagar Belakavadi K, Yathirajan Hemmige S, Cordes David B, Slawin Alexandra M Z, Harrison William T A
Department of Studies in Chemistry, University of Mysore, Manasagangotri, Mysuru 570 006, India.
School of Chemistry, University of St Andrews, Fife KY16 9ST, Scotland.
Acta Crystallogr E Crystallogr Commun. 2019 Jan 8;75(Pt 2):167-174. doi: 10.1107/S2056989018018224. eCollection 2019 Feb 1.
The syntheses and structures of five mol-ecular salts of protonated 4,4,7,7-tetra-methyl-3a,5,6,7a-tetra-hydro-benzo-thia-zol-2-yl-amine (CHNS) with different deprotonated carb-oxy-lic acids (4-methyl-benzoic acid, 4-bromo-benzoic acid, 3,5-di-nitro-benzoic acid, fumaric acid and succinic acid) are reported, namely 2-amino-4,4,7,7-tetra-methyl-4,5,6,7-tetra-hydro-1,3-benzo-thia-zol-3-ium 4-methyl-benzoate, CHNS·CHO , (I), 2-amino-4,4,7,7-tetra-methyl-4,5,6,7-tetra-hydro-1,3-benzo-thia-zol-3-ium 4-bromo-benzoate, CHNS·CHBrO , (II), 2-amino-4,4,7,7-tetra-methyl-4,5,6,7-tetra-hydro-1,3-benzo-thia-zol-3-ium 3,5-di-nitro-benzoate, CHNS·CHNO , (III), bis-(2-amino-4,4,7,7-tetra-methyl-4,5,6,7-tetra-hydro-1,3-benzo-thia-zol-3-ium) fumarate, 2CHNS·CHO ,(IV), and the 1:1 co-crystal of bis-(2-amino-4,4,7,7-tetra-methyl-4,5,6,7-tetra-hydro-1,3-benzo-thia-zol-3-ium) succinate and 2-amino-4,4,7,7-tetra-methyl-4,5,6,7-tetra-hydro-1,3-benzo-thia-zol-3-ium hydrogen succin-ate 4,4,7,7-tetra-methyl-3a,5,6,7a-tetra-hydro-benzo-thia-zol-2-yl-amine, 1.5CHNS·0.5CHO ·0.5CHO . 0.5CHNS, (V). In every case, the cation protonation occurs at the N atom of the thia-zole ring and the six-membered ring adopts a half-chair conformation (in some cases, the deviating methyl-ene groups are disordered over two sets of sites). The C-N bond lengths of the nominal -NH=C-NH fragment of the cation are indistinguishable, indicating a significant contribution of the -NH-C=NH resonance form to the structure. The packing for (I)-(V) features a robust local (8) loop motif in which the cation forms two near-linear N-H⋯O hydrogen bonds from the N-H group and H atom of the amine group to the carboxyl-ate group of an adjacent anion [(V) shows disorder of one of these bonds over N-H⋯O and N⋯H-O contributors but the same (8) loop results for both disorder components]. The H atom of the -NH group also forms an N-H⋯O hydrogen bond, which results in [001] chains in (I) and (II), isolated centrosymmetric tetra-mers in (III) and [100] chains in (IV) and (V). Hirshfeld fingerprint plots and contact percentages for the different types of contacts of the cations are discussed.
报道了质子化的4,4,7,7-四甲基-3a,5,6,7a-四氢苯并噻唑-2-基胺（CHNS）与不同去质子化羧酸（4-甲基苯甲酸、4-溴苯甲酸、3,5-二硝基苯甲酸、富马酸和琥珀酸）形成的五种分子盐的合成与结构，即4-甲基苯甲酸-2-氨基-4,4,7,7-四甲基-4,5,6,7-四氢-1,3-苯并噻唑-3-鎓盐，CHNS·C₈H₈O₂，（I）；4-溴苯甲酸-2-氨基-4,4,7,7-四甲基-4,5,6,7-四氢-1,3-苯并噻唑-3-鎓盐，CHNS·C₇H₅BrO₂，（II）；3,5-二硝基苯甲酸-2-氨基-4,4,7,7-四甲基-4,5,6,7-四氢-1,3-苯并噻唑-3-鎓盐，CHNS·C₇H₄N₂O₄，（III）；富马酸双（2-氨基-4,4,7,7-四甲基-4,5,6,7-四氢-1,3-苯并噻唑-3-鎓盐），2CHNS·C₄H₄O₄，（IV）；以及琥珀酸双（2-氨基-4,4,7,7-四甲基-4,5,6,7-四氢-1,3-苯并噻唑-3-鎓盐）与2-氨基-4,4,7,7-四甲基-4,5,6,7-四氢-1,3-苯并噻唑-3-鎓盐氢琥珀酸盐4,4,7,7-四甲基-3a,5,6,7a-四氢苯并噻唑-2-基胺的1:1共晶体，1.5CHNS·0.5C₄H₄O₄·0.5C₄H₅O₄·0.5CHNS，（V）。在每种情况下，阳离子质子化发生在噻唑环的N原子上，六元环呈半椅式构象（在某些情况下，偏离的亚甲基在两组位置上无序）。阳离子的标称-NH=C-NH片段的C-N键长无法区分，表明-NH-C=NH共振形式对结构有显著贡献。（I）-（V）的堆积具有一个强大的局部（8）环基序，其中阳离子从N-H基团和胺基的H原子形成两个近线性的N-H⋯O氢键，连接到相邻阴离子的羧酸根基团上[（V）显示其中一个键在N-H⋯O和N⋯H-O贡献者之间无序，但两种无序成分的（8）环结果相同]。-NH基团的H原子也形成一个N-H⋯O氢键，这导致（I）和（II）中形成[001]链，（III）中形成孤立的中心对称四聚体，（IV）和（V）中形成[100]链。讨论了阳离子不同类型接触的Hirshfeld指纹图谱和接触百分比。
