Pb₆Co₉(TeO₆)₅

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 Pb^II 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 Pb^II atoms are situated in the cavities of the framework and are stereochemically active with one-sided [4]- and [6]-coordinations, respectively.