Reactivity of a N-Coordinated Germylene-Borane Complex: From Ge→B to Ge→Ga Coordination.

Abstract

Reactivity studies of the GeII →B complex L(Cl)Ge⋅BH3 (1; L=2-Et2 NCH2 -4,6-tBu2 -C6 H2 ) were performed to determine the effect on the GeII →B donation. N-coordinated compounds L(OtBu)Ge⋅BH3 (2) and [LGe⋅BH3 ]2 (3) were prepared. The possible tuning of the GeII →B interaction was proved experimentally, yielding compounds 1-PPh2 -8-(LGe)-C10 H6 (4) and L(Cl)Ge⋅GaCl3 (5) without a GeII →B interaction. In 5, an unprecedented GeII →Ga coordination was revealed. The experimental results were complemented by a theoretical study focusing on the bonding in 1-5. The different strength of the GeII →E (E=B, Ga) donation was evaluated by using energy decomposition analysis. The basicity of different L(X)Ge groups through proton affinity is also assessed.