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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]

Abstract: The rare example of protonated aldehyde salt [4-(OH)-3-(OCH3)C6H3CH( O H)][4-(OH)-3-(OCH3)C6H3CHO][TaF6], 1, was isolated in the solid state by the reaction of 4-hydroxy-3-methoxybenzaldehyde (vanillin) with TaF5 in dichloromethane. The product 1 was characterized by X-ray diffraction and IR spectroscopy. The 1:1 reaction of TaF5 with N,N-dimethylaniline in CH2Cl2 cleanly afforded [TaF4(NMe2C6H5)2][TaF6], 2, which was identified by NMR spectroscopy. Attempts of crystallization of 2 resulted in the isolation of the ammonium salt [NHMe2C6H5][TaF6], 3. [Copyright &y& Elsevier]