Rb4Zr3Te16, a one-dimensional zirconium telluride synthesized from molten salt

A new ternary metal telluride, tetrarubidium trizirconium hexadecatelluride, Rb4Zr3Te16, has been synthesized through reactions at 698 K using elemental Zr and an Rb2Te/Te melt as a reactive flux, and characterized by single-crystal X-ray diffraction. Although the structure of this compound is very similar to its Cs4Zr3Te16 analogue, the compounds crystallize in different space groups, the former in C-2h(6)-C2/C and the latter in C-2h(5)-P2(1)/n. Both compounds consist of infinite one-dimensional chains of [Zr3Te16](n)(4n-) separated from each other by Rb+ or Cs+ cations. Within the chain, each Zr atom is surrounded by eight Te atoms to give a distorted bicapped trigonal prism polyhedron. There are two unambiguous Te-Te single bonds of 2.758 (2) and 2.765 (2) Angstrom, and four longer Te ... Te interatomic distances in the range of 2.9277 (14)-3.0445 (18) Angstrom that indicate weak interactions between the adjacent Te atoms. Because of the wide range of Te ... Te interactions, simple formalisms cannot be used to describe the bonding within the chain.