Premium
2,5‐Dimethoxy‐1,4‐bis[2‐(2,4‐dimethoxyphenyl) ethenyl]benzene studied by quantum chemical calculations and single crystal X‐ray diffraction
Author(s) -
Wu G.,
Jacobs S.,
Lenstra A. T. H.,
van Alsenoy C.,
Geise H. J.
Publication year - 1996
Publication title -
journal of computational chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.907
H-Index - 188
eISSN - 1096-987X
pISSN - 0192-8651
DOI - 10.1002/(sici)1096-987x(199612)17:16<1820::aid-jcc3>3.0.co;2-p
Subject(s) - benzene , chemistry , molecule , crystallography , ring (chemistry) , ab initio , single crystal , nuclear magnetic resonance spectroscopy , computational chemistry , ab initio quantum chemistry methods , quantum chemical , stereochemistry , organic chemistry
The configurational isomers of 2,5‐dimethoxy‐1,4‐bis‐[2‐(2,4‐dimethoxyphenyl)ethenyl]benzene have been investigated by ab initio (4‐21G level) and MOPAC‐AM1 semiempirical methods. The calculations were guided by and compared with single crystal X‐ray results of the trans,trans ‐isomer determined at 298 K and 103 K. The barriers of rotation of the latter isomer in the free and the solid state were enumerated. A comparison with related molecules, in particular 1,4‐bis[2‐(3,4,5‐trimethoxyphenyl)ethenyl]benzene, is made. The positioning of substituents is shown to be of importance for ring rotational movements and NMR shifts, as well as for UV /Vis spectroscopy. © 1996 by John Wiley & Sons, Inc.