1. The reactivity of niobium and tantalum pentahalides with imines.
- Author
-
Marchetti, Fabio, Pampaloni, Guido, and Zacchini, Stefano
- Subjects
- *
NIOBIUM , *TANTALUM , *IMINES , *DICHLOROMETHANE , *PROTON transfer reactions , *X-ray diffraction - Abstract
The reactivity of NbCl 5 , NbF 5 and TaCl 5 with a selection of commercial imines was investigated for the first time by using dichloromethane as reaction medium. NbCl 5 reacted with Ph 2 C NH, in 1:2 molar ratio, affording [Ph 2 C NH 2 ][NbCl 5 (N CPh 2 )], 1 , in 55% yield, as result of imine self-protonation. The iminium salt [PhCH NH t Bu][NbCl 6 ], 2 , was isolated in 52% yield from NbCl 5 and PhCH N t Bu (1:1 molar ratio), while a low yield of [ t Bu 2 C NH 2 ][NbCl 6 ], 3 , was identified from NbCl 5 / t Bu 2 C NH. The 1:1 reactions of NbF 5 with Ph 2 C NH and PhCH N t Bu were accompanied by electron interchange and led to the isolation of the salts [Ph 2 C NH 2 ][NbF 6 ], 4 , and [PhCH NH t Bu][NbF 6 ], 5 , respectively, in ca. 50% yields. Few crystals of [Ph 2 C NH 2 ] 2 [Ta 2 Cl 10 O], 6 , were recovered from TaCl 5 /Ph 2 C NH, the anion being probably generated by the action of adventitious water. Compounds 1 – 6 were characterized by elemental analysis, IR and NMR spectroscopy. The structures of 1 , 4 and 6 were ascertained by X-ray diffraction studies. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF