title: Structure of 1,5-benzodiazepinones in the solid state and in solution: Effect of the fluorination in the six-membered ring.
abstract: Two novel tetrafluorinated 1,5-benzodiazepinones were synthesized and their X-ray structures determined. 6,7,8,9-Tetrafluoro-4-methyl-1,3-dihydro-2H-1,5-benzodiazepin-2-one crystallizes in the monoclinic P21/c space group and 6,7,8,9-tetrafluoro-1,4-dimethyl-1,3-dihydro-2H-1,5-benzodiazepin-2-one in the triclinic P-1 space group. Density functional theory studies at the B3LYP/6-311++G(d,p) level were carried out on these compounds and on four non-fluorinated derivatives, allowing to calculate geometries, tautomeric energies and ring-inversion barriers, that were compared with the experimental results obtained by static and dynamic NMR in solution and in solid state.
authors.affiliation: Departamento de Química Orgánica y Bio-Orgánica, Facultad de Ciencias, UNED, Paseo Senda del Rey 9, 28040-Madrid, Spain.
authors.forename: Marta
authors.initials: M
authors.lastname: Pérez-Torralba
authors.forename: Rosa M
authors.initials: RM
authors.lastname: Claramunt
authors.forename: M
authors.initials: M
authors.lastname: Angeles García
authors.forename: Concepción
authors.initials: C
authors.lastname: López
authors.forename: M Carmen
authors.initials: MC
authors.lastname: Torralba
authors.forename: M
authors.initials: M
authors.lastname: Rosario Torres
authors.forename: Ibon
authors.initials: I
authors.lastname: Alkorta
authors.forename: José
authors.initials: J
authors.lastname: Elguero
keywords: DFT; GIAO calculations; X-ray structures; benzodiazepinones; inversion barriers; multinuclear NMR; tautomerism