RESUMEN

The novel oxychloridoselenites(IV) [BMIm][Se3Cl13] (1), [BMIm][Se4Cl15O] (2), [BMIm]2[Se4Cl14O2] (3), [BMPyr]2[Se4Cl14O2] (4), [BMPyr]2[Se6Cl18O4] (5), [BMIm]2[SeCl4O] (6), [BMPyr]2[Se2Cl6O2] (7), and [BMPyr]2[Se6Cl14O6] (8) are prepared by ionic-liquid-based synthesis. Accordingly, SeCl4, SeO2 (1-6), and/or SeOCl2 (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 AlCl3 in addition). Generally, the composition and structure of title compounds can be derived from the tetrameric, heterocubane-type (SeCl4)4 as the initial building unit. Thus, chlorine is successively exchanged by oxygen from 1 to 8. Moreover, the four edge-sharing (SeCl6) octahedra in (SeCl4)4 are increasingly dismantled, ending with a [SeCl4O]2- anion as a single pseudo-octahedron in 6. Based on the weakly coordinating ionic liquid, it is possible to selectively obtain the different species via synthesis near room temperature (20-80 °C). The oxychloridoselenite anions [Se4Cl15O]-, [Se4Cl14O2]2-, [Se6Cl18O4]2-, and [Se6Cl14O6]2- 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.