Opening the third century of polyhalide chemistry: thermally stable complex with "trapped" dichlorine.

Unlike polyhalides of heavier halogens, polychlorides still remain exotic curiosities. Herein, we report preparation and investigation of complexes Cat2{[TeCl6](Cl2)} (cat = 1-methylpyridinium (1) and tetramethylammonium (2))  where dichlorine units are "trapped" by chlorotellurate(IV) anions via a system of non-covalent Cl···Cl interactions. Complex 2 reveals a record thermal stability (>100°C) for inclusion compounds with Cl2, indications that such compounds can be used as solid Cl2 source.