Abstract
| - Dynamic NMR spectroscopy allowed, for the first time, the determination of the π-barriers responsiblefor the enantiomerization processes in derivatives bearing two aryl substituents bonded to a planarframework: this could be achieved in the case of 1,8-di-m-tolylbiphenylene (1) and 1,8-di-m-xylylbiphenylene (2). In derivative 1, the three possible conformers predicted by DFT computations (anti-in, syn, and anti-out) were detected, and in addition, the steric barrier responsible for their interconversioncould be measured. The barriers predicted by DFT calculations were found in satisfactory agreementwith experimental data.
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