Selective Activation of CCl and CF Bonds by SO.+ Radical Cations: An Experimental and Computational Study. Issue 9 (16th July 2013)

• Record Type: Journal Article
• Authors: de Petris, Giulia; Troiani, Anna; Rosi, Marzio; Angelini, Giancarlo; Ursini, Ornella
• Is Part Of: ChemPlusChem. Volume 78:Issue 9(2013:Sep.)
• Page Start: 1065
• Page End: 1072
• Publication Date: 2013-07-16
• Subjects: CH activation -- density functional calculations -- gas‐phase reactions -- mass spectrometry -- radical ions; Chemistry -- Periodicals; 540.5
• DOI: 10.1002/cplu.201300162
• Languages: English
• ISSNs: 2192-6506

Abstract

Abstract: The activation of C–halogen bonds by the SO . + radical cation is investigated in the gas phase. The CCl bond of CH2 Cl2 is activated by fast and effective chloride‐ion transfer, whereas the CF bond of CH2 F2 is activated by a very slow fluoride‐ion transfer. In both cases, thermodynamic and kinetic factors account for the type of process and the observed selectivity, that is, carbon–halogen versus carbon–hydrogen activation, mainly owing to the presence of the sulfur atom. The cleavage of the CCl bond of CH2 Cl2 by SO . + is a rare example of a very effective and selective chloride‐ion abstraction by a metal‐free, sulfur‐centred radical cation. Abstract : SO selective and SO effective! The SO . + radical cation (see figure) selectively activates the carbon–chlorine bond of CH2 Cl2 by chloride‐ion abstraction. The reaction is kinetically favoured over CH activation, which is not experimentally observed. Though much less efficient, the same pattern is observed with CH2 F2 in which the CF bond is very slowly activated by fluoride‐ion transfer to SO . + .