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Z. Naturforsch. 2014,
69b, 995 – 1002
doi:10.5560/ZNB.2014-4044
Preparation and Structural and Spectroscopic Characterization of Triiodides [M(12-Crown-4)2]I3 with M = Na and Rb
Darstellung und strukturelle und spektroskopische Charakterisierung der Triiodide [M(12-Krone-4)2]I3 mit M = Na und Rb
1 Institut für Anorganische Chemie, Universität zu Köln, Greinstrasse 6, D-50939, Köln, Germany
2 Present address: Faculty of Pharmacy and Health Sciences, Ajman University of Science and Technology, P. O. Box 346, Ajman, VAE
Reprint requests to Dr. Zehra Edis. Fax: +971-6-7055221. E-mail:
z.edis@ajman.ac.ae
Received February 6, 2014 / published online October 12, 2014
In memoriam Professor Karl-Friedrich Tebbe
Reddish-brown crystals of [Na(12-crown-4)2]I3 (1) and [Rb(12-crown-4)2]I3 (2) were formed through the reaction of NaI or RbI, I2 and 12-crown-4 in ethanol. Both structures are triclinic, space group P1̅ with Z = 2. The lattice parameters are a = 8.505(2), b = 14.280(3), c = 10.695(2) Å and α = 89.86(2)○, β = 80.00(2)○ and γ = 85.90(2)○; and a = 10.694(2), b = 11.598(2), c = 12.718(2) Å and
α = 71.00(2)○, β = 86.97(2)○ and γ = 67.710(10)○ for 1 and 2, respectively. Both crystal structures contain one independent complex cation without crystallographic symmetry. The anionic parts of both structures consist of two crystallographically independent, isolated, triiodide anions I3− with crystallographic inversion symmetry. The cations are distorted sandwich-like complexes with two 12-crown-4 molecules surrounding the alkali metal atom in the center.
Key words: Triiodide, Crown Ether, Alkali Metal, Crystal Structure, Spectroscopy, Phase Transitions