Alkylidyne Complexes of Molybdenum and Tungsten That Contain the [(3,4,5-C₆H₂F₃NCH₂CH₂)₂NMe]²^- Ligand

Abstract

Reduction of (C6F5NHCH2CH2)2NMe with LiAlH4 produces (3,4,5-C6H2F3NHCH2CH2)2NMe (H2[F3NMe]) in good yield. Reactions between H2[F3NMe] and MCl4 (M = Mo, W) in the presence of NEt3 yield pseudooctahedral paramagnetic compounds of the type [Et3NH]{[F3NMe]MCl3}. Treatment of [Et3NH]{[F3NMe]MoCl3} with 3 equiv of Me3CCH2MgCl produced five-coordinate [F3NMe]Mo(CH2CMe3)(CCMe3), while treatment with 3 equiv of Me3SiCH2MgCl produced five-coordinate paramagnetic [F3NMe]Mo(CH2SiMe3)2. Upon heating, [F3NMe]Mo(CH2SiMe3)2 is converted into diamagnetic {[F3NMe]Mo(CSiMe3)}2. Reactions between [Et3NH]{[F3NMe]WCl3} and Me3CCH2MgCl or Me3SiCH2MgCl lead to five-coordinate diamagnetic complexes of the type [F3NMe]W(CH2R)(CR), where R = CMe3, SiMe3 respectively. X-ray studies confirmed the structures of [F3NMe]Mo(CH2CMe3)(CCMe3) and {[F3NMe]Mo(CSiMe3)}2.