title: Steric effects which determine the conformational preferences and stereodynamic processes of aryl fluorenyl ketones.
abstract: The stereodynamic processes and conformational preferences of two classes of aryl fluorenyl ketones have been investigated by means of dynamic NMR spectroscopy, DFT calculations and X-ray diffraction. When the aryl substituent has two hydrogens in the ortho positions, its rotation is independent of that of the fluorene ring. In contrast, if the two ortho hydrogens are replaced by the bulkier methyl groups (e.g. mesityl fluorenyl ketones), the motion of the aryl ring interacts with the fluorene, and the two rings rotate in a correlated manner.
authors.affiliation: Department of Chemistry, University of Basilicata, via N. Sauro 85, Potenza, 85100, Italy. casarini@unibas.it
authors.forename: Daniele
authors.initials: D
authors.lastname: Casarini
authors.forename: Lodovico
authors.initials: L
authors.lastname: Lunazzi
authors.forename: Andrea
authors.initials: A
authors.lastname: Mazzanti