ic980579q_si_002.pdf (190.67 kB)
K4Au(TlSn3): A Novel Zintl Phase with an Anionic Chain
journal contribution
posted on 1998-09-04, 00:00 authored by Daping Huang, John D. CorbettReactions of the component elements at 1050 °C and then 400 °C in Ta containers generate the black title phase
in good yield. Single-crystal X-ray characterization (monoclinic, C2/c, Z = 4, a = 15.101(3) Å, b = 6.6925(9)
Å, c = 14.389(3) Å, β = 118.61(1)°) revealed a novel infinite chain structure in which ∼D2d
units are made from tetrahedra of disordered Tl + 3Sn that are bridged at opposite edges by four-bonded Au
atoms, and vice versa. The chains have the electron count of a classical Zintl phase in which all elements are
four-bonded. The MOs of the chain fragment and the band structure of the chains are described. A relatively
large gap appears to arise because of the similar energies of Au 6s and the TlSn34- units.