A theoretical and experimental study of the fluxional behaviour of molybdenum dihydrobis- and hydrotris-pyrazolylborates.
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.
Santa María
M Dolores
MD
Departamento de Química Orgánica y Bio-Orgánica, Facultad de Ciencias, UNED, Senda del Rey, 9, E-28040, Madrid, Spain. dsanta@ccia.uned.es
Claramunt
Rosa M
RM
Alkorta
Ibon
I
Elguero
José
J
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