Development of fluorinated,NMR-active spin traps for studies of free radical chemistry |
| |
| Affiliation: | 1. Laboratory of Molecular Biophysics, National Institute of Environmental Health Sciences, P.O. Box 12233, Research Triangle Park, North Carolina 27709, USA;2. Duke University, Department of Chemistry, Durham, North Carolina 27706 USA;1. Department of Chemistry, Faculty of Science, King Abdulaziz University, P. O. Box 80203, Jeddah 21589, Saudi Arabia;2. Center of Excellence for Advanced Materials Research (CEAMR), King Abdulaziz University, P. O. Box 80203, Jeddah 21589, Saudi Arabia;3. Department of Natural Science in Pharmacy, Faculty of Pharmacy, University of Sarajevo, Zmaja od Bosne 8, 71 000 Sarajevo, Bosnia and Herzegovina;4. Department of Chemistry, DAV College, Faridabad, Haryana, India;1. School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871, China;2. Center of High Energy Physics, Peking University, Beijing 100871, China;1. Anhui Province Key Laboratory of Advanced Catalytic Materials and Reaction Engineering, School of Chemistry and Chemical Engineering, Hefei University of Technology, Hefei 230009, P.R. China;2. Division of Nanomaterials and Chemistry, Hefei National Research Center for Physical Sciences at Microscale, CAS Centre for Excellence in Nanoscience, Collaborative Innovation Center of Suzhou Nano Science and Technology, Department of Chemistry, University of Science and Technology of China, Hefei 230026, P.R. China;3. Department of Physics, Nanjing University, Nanjing 210093, P.R. China;4. Department of Modern Mechanics, University of Science and Technology of China, Hefei 230027, P.R. China;1. College of Environmental Science and Engineering, Hunan University, Changsha 410082, China;2. Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, China |
| |
| Abstract: | Five fluorinated analogs of the spin trap phenyl-t-butyl nitrone (PBN) have been synthesized and evaluated for use as NMR-active traps. The introduction of the fluorine substituent allows selective observation of chemical reactions involving the spin traps. Although the paramagnetic adducts themselves are not directly observable by this approach as a consequence of extensive broadening, the reduced forms (hydroxylamines) can be readily observed. NMR studies of the trapping of the phenyl radical produced from the thermal decomposition of phenylazotriphenyl methane have been carried out. The observation of fluorinated benzaldehydes in these studies reflects the formation and subsequent degradation of oxygen-centered radicals under some conditions. Relative trapping efficiencies for the phenyl radical in the series 2-F, 4-F, 2,6-difluoro, 2-CF3, and 4-CF3 substituted PBN analogs have been determined based on an analysis of the 19F NMR resonance intensities of the reduced phenyl radical adducts. The relatively large proton hyperfine coupling constants observed for 2,6-difluoro and 2-CF3 PBN analogs allow direct observation by ESR of adduct formation in solutions containing both PBN and either of these analogs. The introduction of fluorine substituents into the trap has only a small effect on trapping efficiency. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
