Spin Exchange of Nitroxyl Radicals in H2O and D2O
| Autor: | Werner Herrmann, Anita Pahlke, Reinhard Stößer |
|---|---|
| Rok vydání: | 2012 |
| Předmět: |
chemistry.chemical_classification
Free Radicals Chemistry Iodide Electron Spin Resonance Spectroscopy Analytical chemistry Water Kinetic energy Spectral line law.invention Reaction rate Reaction rate constant law Nitrogen Oxides Deuterium Oxide Physical and Theoretical Chemistry Electron paramagnetic resonance Hyperfine structure Spin-½ |
| Zdroj: | The Journal of Physical Chemistry A. 116:952-961 |
| ISSN: | 1520-5215 1089-5639 |
| DOI: | 10.1021/jp209755v |
| Popis: | By means of continuous wave electron spin resonance (cw ESR) in the X and L bands, the spin exchange of series of different concentrations of the spin probes 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO), 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPOL), and 4-(trimethylamino)-2,2,6,6-tetramethylpiperidine-1-oxyl iodide (CAT-1) in H(2)O and D(2)O have been examined. The rate constants k(e) of the spin exchange have been determined by complete spectra simulations, as well as directly from hyperfine line broadenings and concentration depending line shifts. The obtained results showed a good agreement. Their respective differences {k(e)(H(2)O) - k(e)(D(2)O)} could be determined for the first time. They reflect the different influence of the solvents on the spin dynamics but confirm the decrease of the reaction rate in D(2)O, caused by the higher degree of order in this liquid. The spectroscopic and kinetic results presented in this paper establish a further kind of isotopic effect. |
| Databáze: | OpenAIRE |
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