Präparation und Kristallstrukturen von Rb₈In₁₁, K₈Tl₁₁ und Rb₈Tl₁₁sowie Bandstrukturrechnungen zu K₈In₁₁ / Preparation and Crystal Structures of Rb₈In₁₁, K₈Tl₁₁, and Rb₈Tl₁₁ Band Structure Calculations on K₈In₁₁

Abstract

The isotypic compounds K 8 In 11 , Rb 8 In 11 , K 8 Tl 11 , and Rb 8 Tl 11 were prepared from the elements. The crystal structures were determined by single crystal X-ray diffraction methods. (K 8 In 11 : a = 1002.1(3), c = 5089.1(8) pm; Rb 8 In 11 : a = 1030.1(3), c = 5236.7(7) pm; Κ 8 Τl 11 : a = 999.1(3), c = 5084.8(7) pm; Rb 8 Tl 11 : a = 1028.0(3), c = 5230.5(7) pm, R3̄c, Z = 6). The crystal structures contain In 11 - and Tl 11 -clusters, respectively, of pentacapped trigonal prisms. Band structure calculations on K 8 In 11 confirm an [In 11 ] 7 -“anion”, with one excess electron per In 11 -cluster involved in alkalimetal-earthmetal bonding.