Structural Diversity in Homoleptic Lithium Amidomanganate(II) Complexes: Impact of Amine Substitution

Abstract

Expanding the library of structurally characterized lithium amidomanganates(II), here we report a general synthetic approach to access a new series of homoleptic complexes. In situ salt‐metathesis of commercially available reagents afforded tetrabutyl lithium manganate [(TMEDA)2Li2MnBu4] (1) (TMEDA = N,N,N’,N’‐tetramethylethylendiamine) which could be used as a precursor for direct deprotonation of a selection of amines affording a family of homoleptic lithium amidomanganates. Complexes [{Li(THF)4}{Mn(NPh2)3(THF)}] (2), [(THF)LiMn(NCy2)3] (3) (Cy = cyclohexyl), [(HNCy2)LiMn(NCy2)3] (4), [(THF)4Li2Mn(NHMes)4] (5) (Mes = 2,4,6‐trimethylphenyl), and [(TMEDA)2Li2Mn(NHMes)4] (6) have been isolated and structurally characterized as main products. While it is evident that 1 possesses adequate basicity to effect deprotonation of both primary and secondary amines, the exact stoichiometry, constitution, and structural motif of newly generated lithium amidomanganates are governed by the steric and electronic variations of the amide ligands.