Lu Norman, Chiang Hsing Fang, Wei Rong Jyun, Wen Yuh Sheng, Liu Ling Kang
Institute of Organic and Polymeric Materials, National Taipei University of Technology, Taipei 106, Taiwan.
Institute of Chemistry, Academia Sinica, Taipei 115, Taiwan.
Acta Crystallogr C Struct Chem. 2017 Aug 1;73(Pt 8):593-599. doi: 10.1107/S2053229617009512. Epub 2017 Jul 6.
The salts 3-[(2,2,3,3-tetrafluoropropoxy)methyl]pyridinium saccharinate, CHFNO·CHNOS, (1), and 3-[(2,2,3,3,3-pentafluoropropoxy)methyl]pyridinium saccharinate, CHFNO·CHNOS, (2), i.e. saccharinate (or 1,1-dioxo-1λ,2-benzothiazol-3-olate) salts of pyridinium with -CHOCHCFCFH and -CHOCHCFCF meta substituents, respectively, were investigated crystallographically in order to compare their fluorine-related weak interactions in the solid state. Both salts demonstrate a stable synthon formed by the pyridinium cation and the saccharinate anion, in which a seven-membered ring reveals a double hydrogen-bonding pattern. The twist between the pyridinium plane and the saccharinate plane in (2) is 21.26 (8)° and that in (1) is 8.03 (6)°. Both salts also show stacks of alternating cation-anion π-interactions. The layer distances, calculated from the centroid of the saccharinate plane to the neighbouring pyridinium planes, above and below, are 3.406 (2) and 3.517 (2) Å in (1), and 3.409 (3) and 3.458 (3) Å in (2).
3-[(2,2,3,3-四氟丙氧基)甲基]吡啶糖精盐，CHFNO·CHNOS，(1)，以及3-[(2,2,3,3,3-五氟丙氧基)甲基]吡啶糖精盐，CHFNO·CHNOS，(2)，即分别为吡啶鎓与-CHOCHCFCFH和-CHOCHCFCF间位取代基形成的糖精盐（或1,1-二氧代-1λ,2-苯并噻唑-3-olate）盐，通过晶体学研究以比较它们在固态下与氟相关的弱相互作用。两种盐均显示出由吡啶鎓阳离子和糖精阴离子形成的稳定合成子，其中七元环呈现出双氢键模式。(2)中吡啶鎓平面与糖精平面之间的扭转角为21.26 (8)°，(1)中为8.03 (6)°。两种盐还都表现出阳离子-阴离子交替的π-相互作用堆叠。从糖精平面的质心到上方和下方相邻吡啶鎓平面计算得出的层间距，(1)中为3.406 (2)和3.517 (2) Å，(2)中为3.409 (3)和3.458 (3) Å。
