Pentaiodide komplexer Alkalimetall‐Kronenether‐Kationen: Darstellung und strukturelle Charakterisierung der Verbindungen [M(Benzo‐15‐Krone‐5) 2 ]I 5 mit M = Na, K, Rb, Cs

• Published in: Zeitschrift für anorganische und allgemeine Chemie (1950) Vol. 631; no. 4; pp. 654 - 658
• Main Authors: Pantenburg, Ingo, Müller, Ingrid, Tebbe, Karl‐Friedrich
• Format: Journal Article
• Language: English
• Published: 01.03.2005
• ISSN: 0044-2313; 1521-3749
• DOI: 10.1002/zaac.200400410

Abstract Pentaiodides of Complex Alkaline Metal Crown Ether Cations: Synthesis and Structural Characterisation of the Compounds [M(benzo‐15‐crown‐5) 2 ]I 5 , M = Na, K, Rb and Cs The isotypic compounds [M(benzo‐15‐crown‐5) 2 ]I 5 , M = Na, K, Rb and Cs are obtained as single crystals via the reaction of benzo‐15‐crown‐5, MI and iodine (2 : 1 : 2) from ethanol/dichloromethane (1 : 1). These compounds crystallize in the monoclinic space group P2 1 /n with four formula units in the unit cell. The cations form typical sandwich complexes. The volume of the unit cell increases by 4, 3 % from the sodium to the caesium compound, corresponding to the increasing space required by the cations. The pentaiodide units consist of a elongated triiodide unit and two iodine half‐molecules. These iodine molecules are completed by centres of symmetry. The interconnection between the pentaiodide units leads to the formation of zig‐zag chains that run along [001]. Considering the strongly different ionic radii of the alkali‐metal cations, the existence of this number of isotypic structures is rather surprising.