title: 1H and 2H NMR relaxation in hydrogen-bonded solids due to a complex motion: classical jumps over a barrier and incoherent tunneling.
abstract: Equations for the temperature dependence of proton and deuteron spin-lattice relaxation rates and second moments due to a complex motion consisting of classical jumps over a potential barrier and quantum mechanical tunneling through the barrier have been derived. Asymmetric double and triple potential wells are considered. These equations have been employed to analyze proton spin-lattice relaxation data for solid naphthazarin in the laboratory and rotating frames as a function of temperature. It is shown that tunneling plays an important role in the proton transfer dynamics of this compound.
authors.affiliation: Department of Physics, University of South Africa, Pretoria, 0003, South Africa.
authors.forename: E C
authors.initials: EC
authors.lastname: Reynhardt
authors.forename: L
authors.initials: L
authors.lastname: Latanowicz
mesh_terms: D003903:Deuterium; D006860:Hydrogen Bonding; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008956:Models, Chemical; D009285:Naphthoquinones / Q000737:chemistry*; D011522:Protons; D013113:Spin Labels; D013696:Temperature; D013816:Thermodynamics
chemical_list: D009285:Naphthoquinones; D011522:Protons; D013113:Spin Labels; C005503:naphthazarin; D003903:Deuterium