Études comparées des structures cristallines de dérivés halogénés de la cyclohexanone et de la tertiobutyl-4 cyclohexanone

Abstract An X-ray diffraction study of 2(eq),4(ax),6(eq)-trichlorocyclohexanone, cis-2,6-dichloro- and gem-2,2-dichloro-4-tert-butylcyclohexanones shows the existence of a chair form in the solid state. Analysis of the experimental data shows: - an appreciable contraction of the endocyclic angle at the foot of the carbonyl group in the three molecules; - a strong overlap of the electronic clouds of the oxygen atom and the equatorial chlorine atoms in the α position with respect to the CO bond; - a considerable variation of the dihedral angle formed by the OC 1 C 2 and the C 1 C 2 X eq or C 1 C 2 H eq planes in the different molecules; - a negative or positive effect on ring planarity depending on the nature and position of the substituents.