Pb6Co9(TeO6)5

Abstract

Pb6Co9(TeO6)5, hexalead(II) nonacobalt(II) pentatellurate(VI), is isotypic with its nickel(II) analogue. The asymmetric unit contains two Pb atoms (site symmetries .2., ..2), four Co atoms (..2, ..2, 3.., 3.2) two Te atoms (..2, 3..) and six O atoms (all in general positions), with the Te and Co sites in octahedral coordination environments. The crystal structure can be subdivided into two types of layers parallel to (001). The first layer at z ≃ 0.25 is made up of edge-sharing [CoO6] and [TeO6] octahedra, with 1/6 of the octahedral holes not occupied. The second layer, situated at z ≃ 0, consist of an alternating arrangement of PbII atoms and of double octahedra that are made up from face-sharing [CoO6] and [TeO6] octahedra. The two types of layers are linked together through corner-sharing of [CoO6] and [TeO6] octahedra. The PbII atoms are situated in the cavities of the framework and are stereochemically active with one-sided [4]- and [6]-coordinations, respectively.