Skip to main content
Article thumbnail
Location of Repository

Radical pair kinetics in the hydrogen abstraction of benzophenone derivatives in micellar solutions, studied by pulsed microwave irradiation

By J. R. Woodward and Y. Sakaguchi

Abstract

The hydrogen abstraction reaction of benzophenones in micellar interiors was studied by the effect of a short, resonant microwave pulse on the recombination kinetics under magnetic fields of approximately 0.3 T. This technique allows all the significant rate constants in the reaction to be determined, in particular the singlet state recombination rate constant, which is very difficult to accurately determine by other techniques. This is determined to be 1.90 × 107 s-1 for benzophenone (BP) and 1.83 × 107 s-1 for decafluorobenzophenone in sodium dodecyl sulfate (SDS) micelles, indicating that this value is not limited by the rate of spin mixing, and thus that the kinetic approach used is justified. It also indicates that recombination is limited by re-encounter frequency and is not dependent upon substitution in the ketyl radical. All kinetic parameters are extracted for each system using a combination of single pulse and pulse shift measurements. Data are also presented for the reactions of BP in SDS solutions of high salt concentration, in polyoxyethylene dodecyl ether (Brij 35), and in hexadecyltrimethylammonium chloride micelles. The rate constants reveal useful information on the effects of the both the micelle interior and the nature of ketyl radical on the recombination kinetics

Year: 2001
DOI identifier: 10.1021/jp003801x
OAI identifier: oai:lra.le.ac.uk:2381/641
Journal:
Download PDF:
Sorry, we are unable to provide the full text but you may find it at the following location(s):
  • http://hdl.handle.net/2381/641 (external link)
  • http://pubs.acs.org/doi/abs/10... (external link)
  • Suggested articles


    To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.