Abstract
Poly(γ-benzyl L-glutamate) in a concentrated methylene chloride solution is in a liquid crystalline state. The solvent signal of this solution is a doublet due to magnetic dipole—dipole interactions. Separation of the doublet varies with residence time of the sample in the magnetic field after insertion in the NMR probe or after changing the direction of the applied field. This is attributed to the time dependence of the orientation or reorientation of molecules in the magnetic field.The time dependent phenomena were observed by 1H-FT-NMR and a floppy disk drive system. That is, after changing the direction of the applied field the peak height of the upfield one of the methylene chloride doublets first decreases gradually relative to the downfield one, and still later the peak height of the upfield one increases, and finally both peaks become of equal height. This is interpreted through the anisotropy of the diamagnetic susceptibility Δχ for oriented nematic liquid crystals. The theory is given and the potential for obtaining structural information about nematic liquid crystals of polypeptide is discussed.
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Yokoyama, Y., Arai, M. & Nishioka, A. NMR Study of the Time Dependent Dipolar Splitting of Methylene Chloride Protons in Poly(γ-benzyl L-glutamate). Polym J 9, 161–166 (1977). https://doi.org/10.1295/polymj.9.161
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DOI: https://doi.org/10.1295/polymj.9.161