The trigonal prismatic cluster compound W6CCl15 and a carambolage of tungsten clusters in the structure of the heteroleptic cluster compound W30C2(Cl,Br)68.
Reactions between W(6)Cl(12) and carbon halides can initiate a cascade of reactions and reaction products, yielding W(6)Cl(18), W(6)CCl(18), and W(6)CCl(15) with increasing temperature, before decomposition into tungsten carbide is obtained. The new compound W(6)CCl(15) and the new heteroleptic compound W(30)C(2)(Cl,Br)(68) obtained from these reactions were structurally characterized. The structure of W(30)C(2)X(68) combines a carambolage of two distinct octahedral and one centered trigonal prismatic cluster in one structure as refined by X-ray single-crystal diffraction (P1, Z = 1; a = 12.003(2) A, b = 14.862(3) A, c = 15.792(3) A, alpha = 88.75(2) degrees, beta = 68.85(2) degrees, gamma = 71.19(2) degrees). The unit cell content W(30)C(2)X(68) accommodates five hexanuclear tungsten clusters, similar by a total of three octahedral [W(6)X(8)] type clusters and two carbon-centered trigonal prismatic [W(6)CX(12)] type clusters, sharing terminal halogen atoms to form a network structure. The trigonal prismatic cluster compound W(6)CCl(15) (P2(1)/c, Z = 4; a = 9.8830(4) A, b = 11.8945(4) A, c = 17.8670(7) A, beta = 107.883(2) degrees) is related to the already known compound W(6)CCl(16). According to X-ray powder structure refinement, the structure is showing a special connectivity pattern with short intercluster W-W contacts between trigonal prismatic cluster units.
Ströbele
Markus
M
Abteilung für Festkörperchemie und Theoretische Anorganische Chemie, Institut für Anorganische Chemie, Universität Tübingen, Ob dem Himmelreich 7, D-72074 Tübingen, Germany.
Meyer
H-Jürgen
HJ