Weak hydrogen and halogen bonding in 4‐[(2, 2‐difluoroethoxy)methyl]pyridinium iodide and 4‐[(3‐chloro‐2, 2, 3, 3‐tetrafluoropropoxy)methyl]pyridinium iodide. Issue 9 (7th August 2017) - Lu, Norman
Abstract : To enable a comparison between a C—H… X hydrogen bond and a halogen bond, the structures of the two fluorous‐substituted pyridinium iodide salts 4‐[(2, 2‐difluoroethoxy)methyl]pyridinium iodide and 4‐[(3‐chloro‐2, 2, 3, 3‐tetrafluoropropoxy)methyl]pyridinium iodide have been determined. Abstract : 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, C8 H10 F2 NO + ·I −, (1), has a –CH2 OCH2 CF2 H substituent at the para position of the pyridinium ring and 4‐[(3‐chloro‐2, 2, 3, 3‐tetrafluoropropoxy)methyl]pyridinium iodide, C9 H9 ClF4 NO + ·I −, (2), has a –CH2 OCH2 CF2 CF2 Cl 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.