%0 PDF %T OFF-RESONANCE NMR ON NITROGEN-15 IN GUANOSINE and PHASE CYCLING OF QUADRUPOLAR NMR ON OXYGEN-17 IN SILICA. %A Malave, Peter. %8 2017-04-18 %R http://localhost/files/nk322s03b %X Abstract: Nuclear magnetic resonance in the solid state provides a wealth of inter- and intramolecular interactions that can be utilized to provide useful physical information. Chemical shift, dipolar, J-coupling, and quadrupolar interactions are all present in the solid state and provide complementary information on molecular structure and dynamics. In this work, dipolar, J-coupling, and quadrupolar interactions are studied. Lee-Goldburg off-resonance excitation is employed on a sample of 15N enriched guanosine to determine inter and intramolecular nitrogen-hydrogen distances and the scalar J-coupling constant. Satellite transition magic angle spinning is employed on an 17O enriched sample in silica to experimentally study phase cycling effects. Lee-Goldburg decoupling on guanosine is employed to determine scalar coupling in 15N bonded to 1H in guanosine. Experimental results are compared to theoretically predicted results. Results show scaling factors of 0.47 ± 0.03 and 0.39 ± 0.13 compared to theoretical values of 0.58. Also, a hydrogen bond shift in the resonance frequencies is postulated. Lee-Goldburg cross polarization on guanosine is used to probe inter-nuclear distances of 15N bonded to 1H in guanosine. Results are compared to x-ray crystal structures where positions of protons are energetically optimized. Simulation of experimental results is also used to compare x-ray bond lengths to Lee-Goldburg cross polarization results. The Lee-Goldburg results for N-H and N-H2 bonds show stronger agreement with simulation than x-ray results. Differences in distances range from 0.01 to 0.05 Å. N-H hydrogen bond distances are also compared. Finally, phase cycling effects are studied in satellite transition magic angle spinning experiments on 17O in silica. Results show that a variety of phase cycles for the final pulse in the pulse sequence can be employed to give quantitatively the same result. On the other hand, phase cycles for the first and second pulses may significantly alter the spectrum, showing more coherences for smaller numbers of phase cycles.; Thesis (Ph.D.)--Tufts University, 2011.; Submitted to the Dept. of Physics.; Advisor: William Oliver.; Committee: Leon Gunther, Larry Ford, Roger Tobin, and Bernie Gerstein.; Keyword: Physics. %[ 2022-10-12 %9 Text %~ Tufts Digital Library %W Institution