Lu Norman, Wei Rong Jyun, Chiang Hsing Fang, Thrasher Joseph S, Wen Yuh Sheng, Liu Ling Kang
Institute of Organic and Polymeric Materials, National Taipei University of Technology, Taipei 106, Taiwan.
Department of Chemistry, Clemson University, Advanced Materials Research Laboratory, 91 Technology Drive, Anderson, SC, USA.
Acta Crystallogr C Struct Chem. 2017 Sep 1;73(Pt 9):682-687. doi: 10.1107/S2053229617011172. Epub 2017 Aug 7.
To enable a comparison between a C-H...X hydrogen bond and a halogen bond, the structures of two fluorous-substituted pyridinium iodide salts have been determined. 4-[(2,2-Difluoroethoxy)methyl]pyridinium iodide, CHFNO·I, (1), has a -CHOCHCFH substituent at the para position of the pyridinium ring and 4-[(3-chloro-2,2,3,3-tetrafluoropropoxy)methyl]pyridinium iodide, CHClFNO·I, (2), has a -CHOCHCFCFCl substituent at the para position of the pyridinium ring. In salt (1), the iodide anion is involved in one N-H...I and three C-H...I hydrogen bonds, which, together with C-H...F hydrogen bonds, link the cations and anions into a three-dimensional network. For salt (2), the iodide anion is involved in one N-H...I hydrogen bond, two C-H...I hydrogen bonds and one C-Cl...I halogen bond; additional C-H...F and C-F...F interactions link the cations and anions into a three-dimensional arrangement.
为了能够比较C-H…X氢键和卤键，已测定了两种含氟取代的碘化吡啶鎓盐的结构。4-[(2,2-二氟乙氧基)甲基]碘化吡啶鎓，CHFNO·I，(1)，在吡啶鎓环的对位有一个-CHOCHCFH取代基，4-[(3-氯-2,2,3,3-四氟丙氧基)甲基]碘化吡啶鎓，CHClFNO·I，(2)，在吡啶鎓环的对位有一个-CHOCHCFCFCl取代基。在盐(1)中，碘离子阴离子参与一个N-H…I和三个C-H…I氢键，这些氢键与C-H…F氢键一起将阳离子和阴离子连接成三维网络。对于盐(2)，碘离子阴离子参与一个N-H…I氢键、两个C-H…I氢键和一个C-Cl…I卤键；额外的C-H…F和C-F…F相互作用将阳离子和阴离子连接成三维排列。
