MOLECULAR-GEOMETRY AND CIRCULAR-DICHROISM SPECTRA OF BICYCLO[2.2.1]HEPTANE-2,3-DICARBOXYLIC ANHYDRIDES AND IMIDES

Citation
T. Polonski et al., MOLECULAR-GEOMETRY AND CIRCULAR-DICHROISM SPECTRA OF BICYCLO[2.2.1]HEPTANE-2,3-DICARBOXYLIC ANHYDRIDES AND IMIDES, Journal of organic chemistry, 58(11), 1993, pp. 3134-3139
Citations number
32
Categorie Soggetti
Chemistry Inorganic & Nuclear
ISSN journal
00223263
Volume
58
Issue
11
Year of publication
1993
Pages
3134 - 3139
Database
ISI
SICI code
0022-3263(1993)58:11<3134:MACSOB>2.0.ZU;2-I
Abstract
Several tricyclic anhydrides and imides derived from optically active bicyclo[2.2.1]heptane-2,3-dicarboxylic acids were synthesized, and the ir circular dichroism spectra are reported. On the basis of MNDO calcu lations it was estalished that despite rigidity of the norbornane syst em the five-membered rings of succinic anhydride and imide moieties ar e slightly twisted. The chromophores are flexible and can be more or l ess skewed depending on solvent polarity. The chromophore nonplanarity significantly influences magnitude and sign of the first Cotton effec t associated with the lowest energy n-pi electronic transition. The s ign of the second n-pi Cotton effect is governed by vicinal effect of substituents. The crystal structures of three N-(S)-1-phenylethylimid es were solved to establish the configuration at C-2 of the imide moie ties.