Main Group Metal Complexes of Si, Ge and Al with an Unsymmetrical N,N’-Substituted Diamide Ligand

Abstract

Unsymmetrically N,N’-substituted metal amides of silicon, germanium and aluminium were synthesized starting from N-ethyl-2-(n-propylaminomethyl)phenylamine (1, Et,ⁿPr-ampaH₂). Reaction of the dilithium compound of 1 with SiCl₄ gave spirocyclic Si(Et,ⁿPr-ampa)₂ (2) and Cl₂Si(Et,ⁿPr-ampa) (3). Reduction of 3 with potassium resulted in the formation of the corresponding cyclotetrasilane [Si(Et,ⁿPr-ampa)]₄ (4), whereas the reaction of 3 with lithium triethylborohydride gave the dihydro silane H₂Si(Et,ⁿPr-ampa) (5). The corresponding germanium(IV) compounds Ge(Et,ⁿPr-ampa)₂ (6) and Cl₂Ge(Et,ⁿPr-ampa) (7) were synthesized starting from GeCl₄, amine 1 and NEt₃ using appropriate stoichiometric ratios. Reaction of Ge[N(SiMe₃)₂]₂ with amine 1 provided the germylene [Ge(Et,ⁿPr-ampa)]₂ (8). The aluminium dichloro compound Cl₂Al(Et,ⁿPr-ampaH) (9) was obtained either by reaction of the dichlorogermine 7 with lithium aluminium hydride or by reaction of the dilithium salt of 1 with AlCl₃. Reaction of trimethylaluminium with amine 1 provided the amido-amine (CH₃)₂Al(Et,ⁿPr-ampaH) (10) which was converted into the diamide CH₃Al(Et,ⁿPr-ampa) (11) by methane elimination.