I. Molecular transfer of non-equilibrium nuclear spin magnetization. II. Electron resonance of an organic free radical in zero field

• Main Author: Thompson, Don Dean
• Format: Others
• Published: 1960
• Online Access: https://thesis.library.caltech.edu/2813/1/Thompson_dd_1960.pdf; Thompson, Don Dean (1960) I. Molecular transfer of non-equilibrium nuclear spin magnetization. II. Electron resonance of an organic free radical in zero field. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/073X-P405. https://resolver.caltech.edu/CaltechETD:etd-07052006-130411 <https://resolver.caltech.edu/CaltechETD:etd-07052006-130411>

Part I contains a new magnetic resonance technique that has been developed to measure rates of fast molecular processes. The method involves the experimental introduction of a nonequilibrium nuclear magnetization in one system, A, and the subsequent measurement of the rate at which rapid molecular processes transfer this nonequilibrium magnetization to a second system, B. Systems A and B may correspond to different chemical sites in a molecule that give rise to a chemical shift, or to sites that are distinct because of electron coupled spin-spin interaction. This technique has been applied to determinations of the rate of proton exchange between ammonium ions in aqueous solution. Part II contains a description of a theoretical and experimental investigation of zero field electron spin resonance of malonic acid radicals produced by X-irradiation at room temperature. The radicals produced in a single crystal are oriented in a specific manner. The theory involved predicts six lines of equal intensity, except for a very small Boltzmann factor. Some of these transitions have been found experimentally in a small modulation field at 77°K. The electron is presumed to "precess" in the field of the proton; however, the energy levels cannot be explained classically. A detailed account of the experimental apparatus is given.