Reactions of TaF5 with Activated Arenes. Synthesis of [4-(OH)-3-(OCH3)C6H3CH(=O-H)][4-(OH)-3-(OCH3)C6H3CHO][TaF6], a Rare Example of Protonated Aldehyde

The rare example of protonated aldehyde salt [4-(OH)-3-(OCH3)C6H3CH(@OAH)][4-(OH)-3-(OCH3)C6H3- CHO][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(NMe2- C6H5)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.