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Assignment of 13C resonances of a nematic liquid crystal using off-magic angle spinning

✍ Scribed by H. S. Vinay Deepak; Anu Joy; N. Suryaprakash; K. V. Ramanathan

Publisher
John Wiley and Sons
Year
2004
Tongue
English
Weight
143 KB
Volume
42
Category
Article
ISSN
0749-1581

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✦ Synopsis

Abstract

A novel method for assigning the resonances in the ^13^C NMR spectrum of a static liquid crystalline sample in its nematic phase is proposed. The method is based on the fact that the carbon chemical shifts in the isotropic phase and in the oriented phase under static and off‐magic angle spinning (OMAS) conditions are uniquely related by the tensorial property of the CSA tensor, requiring just one OMAS spectrum and the assignment in the isotropic phase. A computational procedure is proposed to take into account deviations arising out of non‐ideal experimental conditions and the assignments are made by identifying the minimum in the differences in the frequencies between calculated and experimental line positions. Practical implementation of the method has also been demonstrated in the case of the liquid crystal N‐(4‐ethoxybenzylidene)‐4‐n‐butylaniline. Copyright © 2004 John Wiley & Sons, Ltd.

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