Synthesis and reactivity of the bulky germanium(IV) trisamide complexes BrGe[N(SiMe 3) 2] 3 and LiGe[N(SiMe 3) 2] 3: X-ray crystal structures of BrGe[N(SiMe 3) 2] 3 and [(Me 3Si) 2N] 3Ge(CH 2CH 2CH 2CH 3)

Abstract

The bulky germanium(IV) trisamide complex BrGe[N(SiMe 3) 2] 3 has been prepared and structurally characterized. Reaction of this material with n BuLi resulted in [(Me 3Si) 2N] 3Ge(CH 2CH 2CH 2CH 3), which has also been structurally characterized, but no reaction with lithium metal was observed in the attempted preparation of LiGe[N(SiMe 3) 2] 3. However, analytically pure LiGe[N(SiMe 3) 2] 3was prepared by the reaction of 3 equivalents of LiN(SiMe 3) 2 with GeI 2. Evidence is presented that this germyllithium reagent is a major by-product in the synthesis of Ge[N(SiMe 3) 2] 2 when the latter reagent is obtained from GeCl 2 · (dioxane) prepared by the method of Kolesnikov et al. Reaction of the germyllithium reagent with 2,6-diphenylphenol yields the mixed Ge/Li cage complex [Li(μ 2-OC 6H 3Ph 2-2,6) 3Ge], which had originally been obtained serendipitously via the reaction of 2,6-diphenylphenol with Ge[N(SiMe 3)] 2.