Premium
The Structure and Conformations of 2‐Thiophenecarboxaldehyde Obtained from Partially Averaged Dipolar Couplings
Author(s) -
Concistrè Maria,
De Luca Giuseppina,
Longeri Marcello,
Pileio Giuseppe,
Emsley James W.
Publication year - 2005
Publication title -
chemphyschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.016
H-Index - 140
eISSN - 1439-7641
pISSN - 1439-4235
DOI - 10.1002/cphc.200500190
Subject(s) - isotopomers , dipole , chemistry , yield (engineering) , residual dipolar coupling , ring (chemistry) , rotation (mathematics) , crystallography , liquid crystal , proton , amplitude , computational chemistry , chemical physics , molecule , molecular physics , physics , organic chemistry , thermodynamics , condensed matter physics , nuclear physics , geometry , mathematics , quantum mechanics
The proton NMR spe ct ra of samples of 2‐thiophenecarboxaldehyde dissolved in a nematic liquid crystalline solvent, including those from all five singly labelled 13 C isotopomers, have been obtained. These have been analysed to yield sets of partially averaged dipolar couplings which have been used to determine the stru ct ure and the relative amounts of the cis and trans forms, which are the two minimum‐energy stru ct ures generated by rotation about the ring–aldehyde bond. A procedure for applying vibrational corrections to the dipolar couplings in the presence of large amplitude motions is discussed.