Premium
Assignment of 13 C resonances of a nematic liquid crystal using off‐magic angle spinning
Author(s) -
Vinay Deepak H. S.,
Joy Anu,
Suryaprakash N.,
Ramanathan K. V.
Publication year - 2004
Publication title -
magnetic resonance in chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.483
H-Index - 72
eISSN - 1097-458X
pISSN - 0749-1581
DOI - 10.1002/mrc.1358
Subject(s) - liquid crystal , isotropy , chemistry , magic angle spinning , spinning , magic angle , phase (matter) , tensor (intrinsic definition) , molecular physics , condensed matter physics , nuclear magnetic resonance spectroscopy , optics , physics , geometry , stereochemistry , organic chemistry , mathematics , polymer chemistry
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.