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Theoretical and Experimental Gas Phase Nuclear Magnetic Resonance

Seth B Blackwell, University of Nebraska - Lincoln

Abstract

Gas phase nuclear magnetic resonance (NMR) spectroscopy is a powerful method, determining physical and chemical properties of molecules and giving insight into internal spin dynamics. Work has been done to significantly expand the known database of gas phase proton and carbon chemical shieldings obtained in the zero-pressure limit, which provide a comparison to computational NMR methods performed in vacuo. The combination of new knowledge of gas phase shieldings and high-resolution capabilities are demonstrated on analysis of natural gas and volatile fractions of crude oil, which gives new applications of gas phase NMR towards the petroleum industry. Furthermore, more insight has been obtained in regards to gas spin-relaxation, particularly in multiple-quantum relaxation through comprehensive pulse sequences to filter double- and zero-quantum coherences. Finally, results will be given of efforts in 13C hyperpolarization via the Haupt effect, as most notably observed in γ-picoline. New enhancements in γ-picoline were obtained through careful sample preparation and more understanding has been achieved though examining the time periods of liquid helium immersion required to generate the hyperpolarization. The hyperpolarization in γ-picoline served as a proof of concept for the application of this paradigm to smaller molecules. Results are given of matrix-isolation techniques in gas phase methyl-rotors with intention to create hyperpolarization through A/E state rotor imbalance of methyl groups at 4.2 Kelvin.^

Subject Area

Physical chemistry

Recommended Citation

Blackwell, Seth B, "Theoretical and Experimental Gas Phase Nuclear Magnetic Resonance" (2018). ETD collection for University of Nebraska - Lincoln. AAI13418955.
https://digitalcommons.unl.edu/dissertations/AAI13418955

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