Synthesis and characterization of ternary trielides Na₇KTr₄ [Tr=In or Tl] including [Tr₄]⁸⁻ Tetrahedra

Abstract

Two new ternary trielides Na7KTr4 (Tr=In, Tl) have been prepared by classical solid‐state reaction from the elements in tantalum ampoules. Both are isostructural to Na7RbTl4 and therefore crystallize in the orthorhombic space group Pbam (a=16.3202(3)/16.2860(6), b=16.3283(2)/16.2835(6), c=11.3094(2)/11.2771(4), V=3013.74(9)/2990.61(18), R1, wR2=0.0249, 0.0384/0.0447, 0.0608). The trielide subunit is built by two crystallographically independent [Tr4]8− tetrahedra. 23Na NMR as well as EPR spectroscopy was employed to characterize the compounds further. DOS calculations showed a (pseudo) band gap at EF for both compounds. Dissolution experiments in liquid ammonia were carried out for the two alkali metal indides Na7KIn4 and Na2In according to the chemistry of group 14 and 15 Zintl anions. After evaporating the solvent, the remaining material was analyzed by powder X‐ray diffraction and proved the formation of NaIn.

[Tl7]7– Clusters in Mixed Alkali Metal Thallides Cs7.29K5.71Tl13 and Cs3.45K3.55Tl7

“…Therefore, first dissolution experiments in liquid ammonia were carried out, which yielded thallium and alkali metal amide as final oxidation products (SI section 11). Similar observations have been made for Na 8– x A x Tl 4 ( A = K, Rb; x = 0, 1). , …”