Gas-phase C-F bond cleavage in perfluorohexane using W-, Si-, P-, Br-, and I-containing ions: comparisons with reactions at fluorocarbon surfaces

Patrick, J. S. ; Pradeep, T. ; Luo, H. ; Ma, S. ; Cooks, R. G. (1998) Gas-phase C-F bond cleavage in perfluorohexane using W-, Si-, P-, Br-, and I-containing ions: comparisons with reactions at fluorocarbon surfaces Journal of the American Society for Mass Spectrometry, 9 (11). pp. 1158-1167. ISSN 1044-0305

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Official URL: http://linkinghub.elsevier.com/retrieve/pii/S10440...

Related URL: http://dx.doi.org/10.1016/S1044-0305(98)00086-5

Abstract

Gas-phase reactions of W-, Si-, P-, Br-, and I-containing ions with the target molecule perfluorohexane at low collision energies (<15 eV) parallel known ion/surface reactions of the same projectile ions at fluorinated self-assembled monolayer surfaces. Charge exchange, dissociative charge exchange, and fluorine atom abstraction are observed and the majority of the projectile ions also undergo reactive charge exchange to produce specific fluorocarbon fragment ions of the target molecule in distinctive relative abundances. Abstraction of up to five fluorine atoms is observed upon collision of W+ with gaseous perfluorohexane, while similar experiments with CI+, SiCl+, and PCl show abstraction of one or two fluorine atoms. Other projectiles, including Si, PCl2+, Br+, CBr+, and I+, abstract only a single fluorine atom. These patterns of fluorine atom abstraction are similar to those observed in ion/surface collisions. Also paralleling the ion/surface reactions, halogen exchange (Cl-for-F) reactions occur between the Cl-containing projectile ions and perfluorohexane to produce C6F12Cl+, a product of chemical modification of the target. Collisions of PCl+. and PCl2+ also result in production of C6F12, indicating that the corresponding surface modification reaction involving molecular defluorination should be sought. Implications for previously proposed mechanisms, new ion/surface reactions, and for the use of gas-phase studies to guide investigations of the ion/surface reactions are discussed.

Item Type:Article
Source:Copyright of this article belongs to American Society for Mass Spectrometry.
ID Code:27473
Deposited On:10 Dec 2010 12:17
Last Modified:17 May 2016 10:41

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