THE SYNTHESIS AND STRUCTURE OF A NEW ZIRCONIUM IODIDE CARBIDE CLUSTER PHASE, CS2ZR7I18C

The title compound is obtained from reactions of CsI, ZrI4, Zr, and C in sealed Ta at 800°C (but not at 850°C). Both Zr6I12C and Zr6I14C are unstable in the presence of CsI. The Cs2Zr7I18C is shown by X-ray crystallography to be isostructural with K2Zr7Cl18H and is better described as Cs2ZrI6 · Zr6I12C, the iodine in the ZrI2-6 groups bonding to metal vertices in six separate carbon-centered clusters (R3̄, Z = 3 for a = 10.744(1) Å, c = 29.409(5) Å, R (F)/Rw = 3.5/4.4%). © 1993 Academic Press, Inc.