NMR Relaxation Times of Benzene Adsorbed on Charcoal: Molecular Rotation and Diffusion
- 1 December 1965
- journal article
- research article
- Published by AIP Publishing in The Journal of Chemical Physics
- Vol. 43 (11) , 3853-3865
- https://doi.org/10.1063/1.1696574
Abstract
NMR relaxation times have been determined as a function of temperature and composition for the protons of benzene adsorbed on charcoal. These relaxation times have been interpreted to give the following conclusions. The benzene molecule rotates more rapidly in a plane perpendicular to its sixfold axis than it does about other axes. The average enthalpy of activation for surface diffusion lies in the range 5–7 kcal/mole. At any composition, surface diffusion is characterized by a distribution of activation enthalpies with a standard deviation of about 1 kcal/mole. There are close to 1020 unpaired electronic spin/cm3. Some evidence for high-energy adsorption sites is presented.Keywords
This publication has 33 references indexed in Scilit:
- Apparent Phase—Transition Effect in the NMR Spin—Spin Relaxation Time Caused by a Distribution of Correlation TimesThe Journal of Chemical Physics, 1965
- Temperature Dependences of Nuclear-Transfer and Spin-Relaxation Phenomena of Water Adsorbed on Silica GelThe Journal of Chemical Physics, 1963
- Sorption and diffusion of simple paraffins in silica-alumina cracking catalystProceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences, 1960
- Calculation of Thermodynamic Functions of Adsorbed Molecules from Adsorption Isotherm Measurements: Nitrogen on Graphon1,2Journal of the American Chemical Society, 1951
- On the interaction of nuclear spins in a crystalline latticePhysica, 1949
- The adsorption of vapours on mercury. II. The entropy and heat of adsorption of non-polar substancesProceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences, 1946
- Statistical Mechanics of Multimolecular Adsorption II. Localized and Mobile Adsorption and AbsorptionThe Journal of Chemical Physics, 1946
- On a Theory of the van der Waals Adsorption of GasesJournal of the American Chemical Society, 1940
- Adsorption of Gases in Multimolecular LayersJournal of the American Chemical Society, 1938
- An analysis by adsorption of the surface structure of graphiteProceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences, 1937