Untersuchungen an Polyhalogeniden, XXXXII [1]. Das Pentaiodid-Ion I5 -; Eine Übersicht: Darstellung und Kristallstruktur der Verbindung [Rb(C16H24O6)](I5) · H2O

Abstract

Abstract [Rb(benzo-18-crown-6)](I5) H2O could be prepared by the reaction of benzo-18-crown-6, rubidium iodide, and iodine in ethanol / dichloromethane. It crystallizes in the monoclinic space group P21/a with a = 1881.8(3), b = 1439.0(2), c = 2269.0(3) pm, ß = 111.24(1)° and Z = 8. The crystal structure was refined to RF = 0.038 for 5310 reflections. It contains two independent molecules. The two cations and the coordinating water molecules form a zigzag chain running along [100] paralleled by two structurally similar pentaiodide chains with one leg of the V-shaped pentaiodide ion forming the backbone of the chain. In both cases the other leg stands out in a novel fashion without forming a coplanar cis or trans configuration known from other pentaiodides. Anionic motifs of other crystalline pentaiodides are summarized and discussed.