The Binary Iodine-Chlorine Octahalide Series [I Cl ] (n=3, 3.6, 4).

The octanuclear iodine-chlorine interhalides [I Cl ] and [I Cl ] were prepared in two steps. Firstly, addition of ICl to the triaminocyclopropenium chloride salt [C (NEt ) ]Cl forms the trihalide ICl salt, secondly, addition of half an equivalent of I or ICl, respectively, gave the desired products upon crystallization at low temperature. The non-stoichiometric octahalide [I Cl ] was obtained after heating a CH Cl solution of the ICl salt to reflux for 2 hours followed crystallization. [I Cl ] is best described as two ICl anions bridged by I , whereas [I Cl ] is best described as an [I Cl ] pentahalide with a weak halogen bond to an ICl trihalide. The octahalides were characterized by X-ray crystallography, computational studies, Raman and Far-IR spectroscopies, as well as by TGA and melting point.