title: A theoretical and experimental study of the fluxional behaviour of molybdenum dihydrobis- and hydrotris-pyrazolylborates.
abstract: The fluxional barrier of (dicarbonyl)[dihydrobis(3,5-dimethylpyrazol-1-yl)borato][eta-(1,2,3)-2-methylpropen-1-yl]-molybdenum (1) has been measured and a complete assignment of its (1)H, (13)C and (15)N NMR signals has been carried out. Theoretical calculations at the B3LYP/LANL2DZ level including GIAO absolute shieldings (sigma) have allowed to analyze the molecular contributions to the barrier as well as to assign some signals involved in the fluxional process.
authors.affiliation: Departamento de Química Orgánica y Bio-Orgánica, Facultad de Ciencias, UNED, Senda del Rey, 9, E-28040, Madrid, Spain. dsanta@ccia.uned.es
authors.forename: M Dolores
authors.initials: MD
authors.lastname: Santa María
authors.forename: Rosa M
authors.initials: RM
authors.lastname: Claramunt
authors.forename: Ibon
authors.initials: I
authors.lastname: Alkorta
authors.forename: José
authors.initials: J
authors.lastname: Elguero
mesh_terms: D001881:Borates / Q000737:chemistry*; D002625:Chemistry, Organic / Q000379:methods; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008670:Metals / Q000737:chemistry; D008956:Models, Chemical; D008962:Models, Theoretical; D008968:Molecular Conformation; D008982:Molybdenum / Q000737:chemistry*; D012107:Research Design; D013696:Temperature; D013816:Thermodynamics