Tri-, Penta-, and Octaiodide Salts of Transition Metal Polyether Complexes

Salts of transition metal cations complexed by 12-crown-4, benzo-15-crown-5 or 18-crown-6 with 13, 15- and I-8(2-) anions, are synthesized and their crystal structures are determined by single X-ray diffraction. The crystal structures of 1, 2 and 3 are built up by three different cations with the compositions [Fe(H2O)(6)(12c4)(6)](2+), [Zn(H2O)(2)(b15c5)(3)](2+), [Zn(H2O)(5)(18c6)(2)](2+), and isolated triiodide anions 13, respectively Aside from the cations, the isotypic iron and copper compounds (4, 5) contain crystallographically independent V-shaped pentaiodide anions which are linked to dimers by weak interionic contacts. Furthermore, the structures contain centrosymmetric I-8(2-) anions. An investigation of possible secondary contacts reveals that the iodine Substructure of 4 and 5 consists of essentially isolated octaiodide units.