title: ENDOR evidence for the quantum exchange of the methylene protons.
abstract: ENDOR spectroscopy was used for studying methylene proton couplings in the 6-yl (or H-addition) radical in a single crystal of 1-methyluracil at 4.2K. The two methylene protons were magnetically equivalent in all crystal (radical) orientations in the magnetic field, indicating proton quantum exchange. The two protons compose magnetically single entity with spin I=1. The observed small ENDOR line splittings of about 0.60MHz agree well with the theoretical expectations for such a system.
authors: Department of Pharmacy and Biochemistry, University of Zagreb, Ante Kovacića 1, 100001 Zagreb, Croatia. jaherak@pharma.hr
authors: Janko N
authors: JN
authors: Herak
mesh_terms: D000465:Algorithms; D003198:Computer Simulation; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods*; D008697:Methane / Q000032:analysis* / Q000737:chemistry*; D008956:Models, Chemical; D008958:Models, Molecular; D011522:Protons; D011789:Quantum Theory
chemical_list: D011522:Protons; D008697:Methane