CRYSTAL-STRUCTURE OF K18.5H1.5[CE-3(CO3)(SBW9O33)(W5O18)(3)].14H(2)O

Crystal structure of the title compound, which was isolated from a neu tral solution containing HCO3-, was determined by X-ray diffraction an alysis. It crystallized in monoclinic (C2/m) with crystallographic par ameters of a=28.979(5), b=18.379(4), c=19.461(3) Angstrom, beta=100.21 (1)degrees, Z=4, and V=10201(3) Angstrom(3). The [Ce-3(CO3)(SbW9O33)(W 5O18)(3)](20-) anion possesses a trinuclear [Ce-3(CO3)](7+) core attac hed by one B-alpha type [SbW9O33](9-) and three [W5O18](6-) groups wit h C-3, symmetry. The [Ce-3(CO3)](7+) core has the carbonate group whic h links three Ce3+ cations. A groove is formed between adjacent [W5O18 ](6-) groups in the anion, resulting in three grooves in the anion. Ea ch groove contains two K+ cations contacting the O atoms of the [Ce-3( CO3)](7+), [SbW9O33](9-), and three [W5O18](6-) groups. Other K+ catio ns form O-K-O linkages among the anions in the lattice. (C) 1998 Elsev ier Science S.A.