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The structure of thialene as studied by proton magnetic resonance in a nematic phase
Author(s) -
Suryaprakash N.,
Khetrapal C. L.,
Klein R. F. X.,
Horak V.
Publication year - 1985
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.1260231206
Subject(s) - liquid crystal , chemistry , proton , ring (chemistry) , phase (matter) , proton nmr , dipole , isotropy , spin (aerodynamics) , crystallography , spectral line , azulene , nuclear magnetic resonance , molecular physics , condensed matter physics , stereochemistry , physics , photochemistry , nuclear physics , optics , organic chemistry , astronomy , thermodynamics
1 H NMR studies on thialene (cyclopenta[ b ]thiapyran) oriented in a nematic liquid crystalline phase are reported. The indirect spin‐spin and direct dipolar couplings and the chemical shifts between the protons are derived from the spectral analysis. The intra‐ring proton‐proton indirect couplings derived from the isotropic and nematic phase spectra are in agreement. The inter‐ring proton‐proton couplings, however, could only be obtained from the nematic phase spectra. The structural information extracted from the direct dipolar couplings corresponds to significant distortions in the arrangement of the protons of the six‐ and five‐membered rings from the regular hexagonal and pentagonal arrangements, respectively; the molecular geometry of the fused five‐membered ring is similar to that of the corresponding ring in azulene.