Magic-Angle-Spinning Nuclear Magnetic Resonance

This thesis concerns the development of radio-frequency pulse sequences in magic-angle-spinning solid-state nuclear magnetic resonance. First, two classes of pulse sequences are presented which are synchronized with the sample rotation. Symmetry theorems are described which link the symmetry of the pulse sequences to selection rules for the recoupling and/or decoupling of certain spin interactions. Pulse sequences are demonstrated which recouple direct homonuclear dipolar interactions at high sample spinning frequencies. Several applications are shown, including the ecient excitation of double-quantum coherences, two-dimensional double-quantum spectroscopy, transfer of longitudinal magnetization and two-dimensional correlation spec-troscopy. In addition, generalized Hartmann-Hahn sequences are demonstrated in which radio-frequency irradiation is applied simultaneously to two isotopic spin species. These sequences selectively recouple direct heteronuclear dipolar interactions and suppress all homonuclear interactions for both spin species