title: Cooperative effects of cation size and variable coordination modes of Te(4+) on the frameworks of new alkali metal indium tellurites, NaIn(TeO3)2, KIn(TeO3)2, RbInTe3O8, and CsInTe3O8.
abstract: Four new alkali metal indium tellurites, NaIn(TeO3)2, KIn(TeO3)2, RbInTe3O8, and CsInTe3O8, have been prepared through hydrothermal and solid state synthesis reactions using corresponding alkali metal carbonates, In2O3 [or In(NO3)3·xH2O], and TeO2. The structures of the reported materials have been determined by powder and single crystal X-ray diffraction. The mixed indium tellurites reveal a rich structural chemistry with different channel structures. NaIn(TeO3)2 shows 8-membered rings, whereas stoichiometrically similar KIn(TeO3)2 exhibits both 8- and 12-membered rings in the frameworks. Isostructural RbInTe3O8 and CsInTe3O8 reveal three-dimensional frameworks consisting of InO6, TeO3, and TeO4 groups. Close structural examination suggests that the alkali metal cation size and variable coordination modes of Te(4+) cations cooperatively influence the framework geometries of the new mixed metal tellurites. Detailed characterizations including spectroscopic, elemental, and thermal analyses are introduced. Local dipole moments and out-of-center distortions for the constituent polyhedra are also reported.
authors.affiliation: Department of Chemistry, Chung-Ang University , 84 Heukseok-ro, Dongjak-gu, Seoul 156-756, Republic of Korea.
authors.forename: Su-Whan
authors.initials: SW
authors.lastname: Bae
authors.forename: Choong-Yeol
authors.initials: CY
authors.lastname: Kim
authors.forename: Dong Woo
authors.initials: DW
authors.lastname: Lee
authors.forename: Kang Min
authors.initials: KM
authors.lastname: Ok