ISSN:
0018-019X
Keywords:
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The π-bond configurations, the conformations, and the dynamic behaviour of dibenzo [c,j]octalene (2) and of benzo [c]octalene (3) have been investigated by 13C-NMR. spectroscopy at different temperatures. Dibenzooctalene was found to present π-bond fixation in the octalene unit as in 2b; with this π-bond fixation the molecule is not planar and takes two different conformations which are rapidly interconverted by inversion of one cyclooctatetraene ring. Monobenzooctalene (3) also presents π-bond fixation in the octalene unit but exists as two valence isomers, 3b and 3c. Isomer 3c dominates the dynamic equilibrium. With this π-bond configuration, the molecule is chiral but undergoes several isodynamic processes, namely inversion of the cyclooctatriene and/or of the cyclooctatetraene ring. The valence isomer 3b can have two different conformations which are rapidly interconverted by inversion of one cyclooctatetraene ring. The interconversion 3c ⇌ 3b implies the occurrence of a π-bond shift process; this process affects the 13C-NMR. lineshape above 50°.
Additional Material:
13 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/hlca.19800630834
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