The advent of boron‐containing cumulenes as carbodiimide analogs allows for the one‐pot synthesis of low‐valent main‐group species stabilized by a dianionic bis (borylamido) ligand chelate. Here, the synthesis and characterization of germylene complexes accessed via the reaction of GeCl 2 ·dioxane with K (HCDippN) 2 BNBNB (NDippCH) 2 (K (boryl) NBN (boryl), 1) is reported. The four‐membered N‐heterocyclic germylene ClB (boryl) N 2 Ge (2‐Cl) generated reacts further with 1, 3, 4, 5‐tetramethylimidazol‐2‐ylidene (IMe 4) to yield the structurally characterized Ge‐bound adduct ClB (boryl) N 2 Ge·IMe 4 (3‐Cl). Reaction with trimethylsilyl azide (Me 3 SiN 3) then affords the related azido‐functionalized system (N 3) B (boryl) N 2 Ge·IMe 4 (3‐N 3). Density functional theory and natural bond orbital analyses of 2‐Cl reveal a greater partial positive charge at Ge versus B (+1. 37 vs. +0. 90 e) ; taken together with the relative unimportance of GeN π bonding (WBIs: GeN 0. 44/0. 46; BN: 0. 93, 0. 94), these data rationalize the uptake of IMe 4 at germanium, rather than boron in a molecule offering two Lewis acidic centers (i. e. 3‐Cl / 3‐N 3).
Tang et al. (Thu,) studied this question.