The structure of the title compounds was examined by means of ab initio MO theory employing the STO-3G basis set. The optimized geometries represent a good basis for the discussion of conformation and configuration of these molecules. A quantum-chemical solvation model was applied for the estimation of the solvent influence. Dependent on the extent of push-pull conjugation in the investigated systems, the conformation of the linear inversion state, which has to be passed during the isomerization process, changes between a planar and perpendicular orientation of the N-phenyl ring. These conformation differences could be responsible for deviations of Hammett plots of the isomerization rate from linearity for special groups of aromatic azomethines.
Structure and thermal E-Z isomerization of substituted 4-Phenylimino-5-pyrazolones and hexafluoroacetones anils
CIMIRAGLIA, Renzo;
1993
Abstract
The structure of the title compounds was examined by means of ab initio MO theory employing the STO-3G basis set. The optimized geometries represent a good basis for the discussion of conformation and configuration of these molecules. A quantum-chemical solvation model was applied for the estimation of the solvent influence. Dependent on the extent of push-pull conjugation in the investigated systems, the conformation of the linear inversion state, which has to be passed during the isomerization process, changes between a planar and perpendicular orientation of the N-phenyl ring. These conformation differences could be responsible for deviations of Hammett plots of the isomerization rate from linearity for special groups of aromatic azomethines.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.