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Determination of the Quadrupolar Coupling Constant and the Asymmetry Parameter of Oxygen‐17 in Acetone by 17 O‐ and 1 H‐NMR in Nematic Phases
Author(s) -
Tricot Yves,
Niederberger Werner
Publication year - 1984
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.19840670416
Subject(s) - chemistry , coupling constant , asymmetry , liquid crystal , polar , spectral line , acetone , nmr spectra database , inverse , coupling (piping) , analytical chemistry (journal) , crystallography , condensed matter physics , organic chemistry , physics , geometry , mechanical engineering , mathematics , quantum mechanics , engineering , particle physics , astronomy
Linear relationships between the inverse of the quadrupolar coupling constant, 1/χ and the asymmetry parameter η are obtained for the 7 O‐nucleus of acetone oriented in four different nematic phases, using the information contained in 1 H‐ and 17 O‐NMR spectra. The absence of a unique intersecting point of thee relations shows that the quadrupolar constants differ slightly between polar and apolar nematic phases, while the orientation remains similar. By combination of the experimentally derived relations with predictions from the theory of Townes and Dailey , values for χ = 11.15 MHz and η = 0.47 in polar media and χ = 11.35 Mhz and η = 0.15 in an apolar medium are obtained, which are similar to those found in the gas and solid phases.