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Internet Electronic Journal of Molecular Design - IEJMD, ISSN 1538-6414, CODEN IEJMAT
| ABSTRACT - Internet Electron. J. Mol. Des. November 2002, Volume 1, Number 11, 593-602 |
Angular Group Induced Bond Alternation (AGIBA). Part IX.
Interactions with the Pyrimidine Ring
Tadeusz Marek Krygowski, Edyta Pindelska, Michal Ksawery Cyranski, and Jacek Nowacki
Internet Electron. J. Mol. Des. 2002, 1, 593-602
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Abstract:
Angular groups attached to the aromatic rings cause an increase of the
double bond localization called Angular Group Induced Bond
Alternation (AGIBA). The effect for the groups with single bonds,
X-Y, increases the double bond character of the s-cis CC bond in the
ring, whereas the groups with double bonds, X=Y, work in the
opposite direction, increasing the single bond character of the s-cis
bond. The effect for pyrimidine ring is studied by use of the X-ray
diffraction geometry of
(E)-4-[2-(4-methoxyphenyl)ethenyl]-2-methylpyrimidine and
optimized geometry of substituted in various
positions vinylo, formylo, imino, nitroso and methoxy derivatives of
pyrimidine optimized at B3LYP/6-311G** level of theory. The
AGIBA effect is less expressed in the pyrimidine derivatives
compared to that observed for benzene derivatives.
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