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The Structure of Acrolein in a Liquid Crystal Phase
Author(s) -
Celebre Giorgio,
Concistrè Maria,
De Luca Giuseppina,
Longeri Marcello,
Pileio Giuseppe,
Emsley James William
Publication year - 2005
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.200401059
Subject(s) - acrolein , phase (matter) , materials science , liquid crystal , crystallography , chemistry , organic chemistry , optoelectronics , catalysis
The 1 H NMR spectrum of a sample of acrolein dissolved in the nematic liquid crystal phase I52 has been analysed to yield 18 dipolar couplings between all the magnetic nuclei in the molecule; moreover, the 13 C and 13 C{ 1 H} NMR spectra of a sample of acrolein in CDCl 3 were recorded and analysed to determine the indirect J ij couplings. The data were used to obtain the relative positions of the carbon and hydrogen atoms, assuming that these are independent of the conformations generated by rotation around the CC bond through an angle ϕ , and to obtain a probability distribution P ( ϕ ). It has been found that in the liquid phase, the distribution is a maximum at the trans form whereas the abundance of the cis form is significantly smaller compared with that found by microwave spectroscopy or high level quantum mechanical calculations. Such calculations produced also a suitable force field needed to develop suitable strategies for vibrational correction procedure in the case of flexible molecules.