Abstract
The new thallium hydroxocarbonate Tl4(OH)2CO3 has been obtained by evaporation from aqueous solution. The crystal structure of the compound has been solved by direct methods: orthorhombic, Cmc21, a = 8.9963(18), b = 12.1500(30), c = 7.9542(15) Å, V = 869.43(3) Å3, R1 = 0.056 for 763 unique reflections with |Fo| ≥ 4σF. There are three symmetrically independent Tl+ cations in the structure. The O atoms of the OH- groups are triangularly coordinated by three Tl atoms that results in formation of OHTl3 triangles with the O atom located at approx. 1.00 Å above the Tl3 plane. The OH- centered units are connected via common edges into [OH2Tl4]2+ dimers linked into chains through Tl–O bonds to CO3 groups. The structure contains channels parallel to the c axis. The formation of the lone pair cavity causes repulsion of Tl+ cations across these cavities and, as a consequence, distortion of the Tl+ cation arrangement.
© by Oldenbourg Wissenschaftsverlag, München, Germany
