Synthesis and crystal structure of bis-(9-mesityl-9,10-di-hydro-10-aza-9-borabenzo[]quinolinato-κ,)zinc(II).

The title compound, [Zn(CHBN)] ( ), is an overall uncharged chelate that consists of two units of an N-deprotonated 10-aza-9-borabenzo[]quinoline ligand () per Zn center. It was synthesized in two steps by treating the protonated ligand with lithium bis-(tri-methyl-sil-yl)amide and further conversion with di-ethyl-zinc. Its asymmetric unit comprises one fragment; the mol-ecule is completed by application of inversion symmetry at Zn. Due to the fourfold coordination with nitro-gen atoms, the zinc(II) ion is located in a distorted tetra-hedral environment. Besides the relatively short N-Zn bonds, is characterized by the significant protrusion of the central ion from the plane of the ligand backbone. The crystal structure is consolidated by intra- and inter-molecular π-π stacking inter-actions, while the polarized B-N bond is barely involved in any close atom contacts.