A Facile Route for the Synthesis of Polycationic Tellurium Cluster Compounds: Synthesis in Ionic Liquid Media and Characterization by Single-Crystal X-Ray Crystallography and Magnetic Susceptibility
Résumé
An innovative soft chemical approach has been applied, using ionic liquids as an alternative reaction medium for the synthesis of tellurium polycationic cluster compounds at room temperature. [Mo2Te12]I6, Te6[WOCl4]2, and Te4[AlCl4]2 have been isolated from the ionic liquid [BMIM]Cl/AlCl3 ([BMIM]+: 1-n-butyl-3-methylimidazolium) and characterized. Black, cube-shaped crystals of [Mo2Te12]I6, which is not accessible by conventional chemical transport reaction, are obtained by reacting the elements at room temperature in [BMIM]Cl/AlCl3. The monoclinic structure (P21/n, a = 1138.92(2) pm, b = 1628.13(2) pm, c = 1611.05(2) pm, β = 105.88(1) °) is homeotypic to the triclinic bromide [Mo2Te12]Br6. In the binulear complex [Mo2Te12]6+, the molybdenum(III) atoms are η4-coordinated by terminal Te42+ rings and two bridging η2-Te22– dumbbells. Despite the short Mo···Mo distance of 297.16(5) pm, coupling of the magnetic moments is not observed. The paramagnetic moment of 3.53 μB per molybdenum(III) atom corresponds to an electron count of seventeen. Black crystals of monoclinic Te6[WOCl4]2 are obtained by the oxidation of tellurium with WOCl4 in [BMIM]Cl/AlCl3. Tellurium and tellurium(IV) synproportionate in the ionic liquid at room temperature yielding violet crystals of orthorhombic Te4[AlCl4]2.
Origine : Fichiers produits par l'(les) auteur(s)
Loading...