The octanuclear iodine‐chlorine interhalides [I4Cl4]2− and [I3Cl5]2− were prepared in two steps. Firstly, addition of ICl to the triaminocyclopropenium chloride salt [C3(NEt2)3]Cl forms the trihalide ICl2− salt, secondly, addition of half an equivalent of I2 or ICl, respectively, gave the desired products upon crystallization at low temperature. The non‐stoichiometric octahalide [I3.6Cl4.4]2− was obtained after heating a CH2Cl2 solution of the ICl2− salt to reflux for 2 hours followed crystallization. [I4Cl4]2− is best described as two ICl2− anions bridged by I2, whereas [I3Cl5]2− is best described as an [I2Cl3]− pentahalide with a weak halogen bond to an ICl2− trihalide. The octahalides were characterized by X‐ray crystallography, computational studies, Raman and Far‐IR spectroscopies, as well as by TGA and melting point.

Rational Synthesis, Structures and Properties of the IonicL iquid Binary Iodine-BromineO ctahalideS eries [I n Br 8À Àn ] 2À À (n = 0, 2, 3, 4) Abstract: As eries of octanuclear iodine-bromine interhalides [I n Br 8Àn ] 2À (n = 0, 2, 3, 4) were prepareds ystematically in two steps. Firstly,a ddition of ad ihalogen (Br 2 or IBr) to the triaminocyclopropenium bromide salt [C 3 (NEt 2 ) 3 ]Br forms the corresponding trihalide salt with Br 3 À or IBr 2 À anions, respectively.S econdly, additiont oB r 3 À of half an equivalent of Br 2 gives the octabromine polyhalide [Br 8 ] 2À ,w hereas addition to IBr 2 À of half an equivalent of Br 2 ,I Br or I 2 gives the corresponding interhalides:[ I 2 Br 6 ] 2À ,[ I 3 Br 5 ] 2À ,a nd [I 4 Br 4 ] 2À ,r espectively.T he four octahalides were characterized by X-ray crystallography,c omputationals tudies, Ramana nd Far-IR spectroscopies, as well as by TGA and melting point. All of the salts werefound to be ionic liquids.Scheme1.The iodine-bromine interhalide family.[a] M.

Iodine–chlorine polyhalides are prepared systematically from their constituents in conjunction with a triaminocyclopropenium template. The polyhalide structures are held together with halogen bonds and supported by interactions to the cation via CH