Synthesis and structure of the azidogermyliumylidene azide complex [L(N3)Ge:]+N3− with covalently and ionically bonded azide ligands at germanium(ii) [L = bis(N-heterocyclic carbene)]

Abstract

Starting from the chlorogermyliumylidene chloride salt [L(Cl)Ge:]Cl (1) (L = 1,1′-methylene-3,3′-di-2,6-diisopropyl-phenylimidazole-2,2′-diylidene), the chloride ion can be easily substituted by BPh₄ to yield [L(Cl)Ge:]BPh₄ (3). Reaction of the latter with NaN₃ furnishes [L(N₃)Ge:]BPh₄ (4). In contrast, the direct reaction of 1 with NaN₃ affords exclusively the first azidogermyliumylidene azide salt [L(N₃)Ge:]N₃ (2). The latter represents the first isolable diazido Ge(II) complex with a covalently bonded azido ligand and a weakly coordinating azide anion as the counterion. All new compounds 2, 3, and 4 were fully characterized, including using X-ray diffraction analysis.