Editing SN2 reaction (section)

==Roundabout mechanism==
A development attracting attention in 2008 concerns a S<sub>N</sub>2 '''roundabout mechanism''' observed in a gas-phase reaction between chloride ions and [[methyl iodide]] with a special technique called ''crossed molecular beam imaging''. When the chloride ions have sufficient velocity, the initial collision of it with the methyl iodide molecule causes the methyl iodide to spin around once before the actual S<sub>N</sub>2 displacement mechanism takes place.<ref>''Imaging Nucleophilic Substitution Dynamics'' J. Mikosch, S. Trippel, C. Eichhorn, R. Otto, U. Lourderaj, J. X. Zhang, W. L. Hase, M. Weidemüller, and R. Wester Science 11 January '''2008''' 319: 183-186 {{doi| 10.1126/science.1150238}} (in Reports)</ref><ref>''PERSPECTIVES CHEMISTRY: Not So Simple'' John I. Brauman (11 January 2008) Science 319 (5860), 168. {{doi|10.1126/science.1152387}}</ref><ref>''Surprise From SN2 Snapshots Ion velocity measurements unveil additional unforeseen mechanism'' Carmen Drahl [[Chemical & Engineering News]] January 14, '''2008''' Volume 86, Number 2 p. 9 http://pubsapp.acs.org/cen/news/86/i02/8602notw1.html, video included</ref>