Crystal structure and Hirshfeld surface analysis of 1,4-di-aza-bicyclo-[2.2.2]octane-di-ium bis-(tribromide)

The crystal structure of the title salt, 1,4-di-aza-bicyclo-[2.2.2]octane-di-ium bis-(tribromide), (C₆H₁₄N₂)[Br₃]₂, consists of diprotonated 1,4-di-aza-bicyclo-[2.2.2]octane-di-ium (or tri-ethyl-enedi-amine) cations, which are separated by [Br₃]^- anions. Br⋯Br contacts between polybromide anions generate supra-molecular two-dimensional layers propagating along the bc plane. Organic cations are accommodated inside anionic layers and inter-act with tribromide anions through N-H⋯Br contacts. The structure is additionally stabilized by weak C-H⋯Br inter-actions linking the organic cations and [Br₃]^-. Hirshfeld surface analysis and associated fingerprint plots reveal that the main contributions to the crystal packing are provided by Br⋯H inter-actions (84.8%), followed by less chemically meaningful H⋯H (15.2%) contacts. As a novel example of a tribromide salt, the reported com-pound is of inter-est toward its potential use in organic synthesis as a regioselective brominating agent, in oxidation chemistry, and in materials processing involving metal dissolution and recovery.