Proton-coupled carbon-13 sample spinning NMR studies of macromolecules and ordered systems

e have studied a variety of macromolecular systems such as lipid/water lyotropic phases and elastomeric polymers, and in addition a thermotropic liquid-crystal displaying macroscopic orientational ordering behavior, by Carbon-13 (;Since the DD/CSA effects are quite novel and have not been treated in detail experimentally or theoretically, we have extended the previous theories to a more realistic anisotropic motional model and have attempted to explain the proton-coupled ;We have also tried to extend the usefulness of PC-MAS relaxation cross-correlation study to a thermotropic liquid crystal; and in the process we have determined the effects which sample spinning in a magnetic field can have on an ordered phase such as the nematic phase of a liquid crystal. Our findings indicate that rapid spinning of the sample can lead to destruction of the macroscopic order-director alignment along the sample spinner axis. In order to avoid this difficulty "off-axis" spinning experiments are done to show that the stability of the order director can be maintained. With the added precaution we show that proton-coupled...