Correlated rotations in benzylfluorene derivatives: structure, conformation, and stereodynamics.
Fluorene derivatives, having substituted benzyl groups bonded to position 9, have been investigated by variable temperature NMR spectroscopy. Stereodynamic processes involving restricted rotation about the fluorenyl-CH2 and aryl-CH2 bonds have been observed, leading to conformers and enantiomeric forms, and the corresponding barriers were determined by line shape simulation. These dynamic processes are interpreted as being due to correlated rotation pathways, on the basis of DFT computations that satisfactorily reproduce the experimental barriers. The structures of two such compounds were also determined by single-crystal X-ray diffraction.
Casarini
Daniele
D
Department of Chemistry, University of Basilicata, via N. Sauro 85, Potenza 85100, Italy. casarini@unibas.it
Lunazzi
Lodovico
L
Mazzanti
Andrea
A
D003198:Computer Simulation; D018360:Crystallography, X-Ray; D005449:Fluorenes / Q000138:chemical synthesis / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods / Q000592:standards; D008956:Models, Chemical; D008958:Models, Molecular; D008968:Molecular Conformation; D012015:Reference Standards; D012399:Rotation; D013237:Stereoisomerism; D013816:Thermodynamics
D005449:Fluorenes