2001 structure

structure (solids and liquids)D 2000

45 - 007Polycationic Hg-Pnictide Frameworks with a Novel Kind of Fillingin the Structures of Hg3As2TlCl3 and Hg3Sb2TlBr3. — Thetitle compounds are prepared in nearly quantitative yields from mixtures ofHg2X2, HgX2 (X: Cl, Br), As or Sb, and Tl (evacuated glass tubes, temp.gradients 330→290 ◦C for the As compound and 290→260 ◦C for the Sbcompound, 2 weeks). As revealed by single crystal XRD, both compoundscrystallize in the orthorhombic space group Pbcm with Z = 4. The structurescan be described either as a cubic closest packing of As2/Sb2 dumbbells andhalide anions with all octahedral interstices filled with Hg2+ and Tl+, or as apolycationic framework (Hg3Z2)2+ (Z: As, Sb) consisting of pnictide–pnictidedumbbells each connected by six Hg atoms to a three-dimensional porousnetwork. The bonding character of the Tl–halide and Hg–halide bonds isexplained using extended Hueckel band structure calculations. — (BECK, JO-HANNES; NEISEL, UDO; Z. Anorg. Allg. Chem. 627 (2001) 8, 2016-2022; Inst.Anorg. Chem., Rhein. Friedrich-Wilhelms-Univ., D-53121 Bonn, Germany; DE)

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