Synthesis of a Hexachloro Sulfate(IV) Dianion Enabled by Polychloride Chemistry

The preparation and structural characterization of [NEt(3)Me](2)[SCl(6)] is described, which is the first example of a [SCl(6)](2−) dianion and of a halosulfate anion of the type [S( x )X( y )]( z−) in general. This dianion belongs to the group of 14‐valence electron AB(6)E systems and forms an octahedral structure in the solid‐state. Interestingly, co‐crystallization with CH(2)Cl(2) affords [NEt(3)Me](2)[SCl(6)]⋅4 CH(2)Cl(2) containing [SCl(6)](2−) dianions with c (4v ) symmetry. As suggested by quantum‐chemical calculations, the distortion of the structure is not caused by a stereochemically active lone pair but by enhanced hydrogen bonding interactions with CH(2)Cl(2). At elevated temperatures, [NEt(3)Me](2)[SCl(6)] decomposes to various sulfur chlorine compounds as shown by Raman spectroscopy. Cooling back to room temperature results in the selective formation of [NEt(3)Me](2)[SCl(6)] which is comparable to the well‐studied SCl(4).