ON THE CROWN-ETHER COMPLEXES (K(15-CROWN-5)2)3(SB3I12), (TECL3(15-CROWN-5))(TECL5), AND (TECL3(15-CROWN-5))2(TECL6)

Orange-coloured crystals of [K(15-crown-5)2]3[Sb3I12] are formed in the reaction of potassium iodide with antimony triiodide and 15-crown-5 in acetonitrile solution. An X-ray structure determination reveals severe disorder of the crown ether molecules, which coordinate to the potassium atoms in a sandwich array; so only the [Sb3I12]3- ion and the potassium positions were ascertained. The anion is a centrosymmetric trimer (symmetry C2h), which can be understood as central SbI63- ion, coordinated by two SbI3 molecules. (Space group C2/m, Z = 2, 3263 observed, independent reflections, R = 0.06, lattice dimensions at 20-degrees-C: a = 2541.1 pm, b = 1441.7 pm, c = 1588.4 pm, beta = 113.33-degrees. The tellurium complexes [TeCl3(15-crown-5)] [TeCl5] and [TeCl3(15-crown-5)]2[TeCl6] are prepared by reaction of TeCl4 with 15-crown-5 in acetonitrile solution, forming yellow-green crystals sensitive to moisture. They are characterized by their i.r. spectra.