Oxychloridoselenites(IV) with cubane-derived anions and stepwise chlorine-to-oxygen exchange.

The novel oxychloridoselenites(IV) [BMIm][SeCl] (1), [BMIm][SeClO] (2), [BMIm][SeClO] (3), [BMPyr][SeClO] (4), [BMPyr][SeClO] (5), [BMIm][SeClO] (6), [BMPyr][SeClO] (7), and [BMPyr][SeClO] (8) are prepared by ionic-liquid-based synthesis. Accordingly, SeCl, SeO (1-6), and/or SeOCl (7,8) as the starting materials are reacted in [BMIm]Cl or [BMPyr]Cl as ionic liquid (BMIm: 1-butyl-3-methylimidazolium, BMPyr: 1-butyl-1-methylpyrrolidinium; partially with AlCl in addition). Generally, the composition and structure of title compounds can be derived from the tetrameric, heterocubane-type (SeCl) as the initial building unit. Thus, chlorine is successively exchanged by oxygen from 1 to 8. Moreover, the four edge-sharing (SeCl) octahedra in (SeCl) are increasingly dismantled, ending with a [SeClO] anion as a single pseudo-octahedron in 6. Based on the weakly coordinating ionic liquid, it is possible to selectively obtain the different species synthesis near room temperature (20-80 °C). The oxychloridoselenite anions [SeClO], [SeClO], [SeClO], and [SeClO] are obtained for the first time. The title compounds are characterized by X-ray structure analysis based on single crystals and powders as well as by infrared spectroscopy and thermal analysis.