The Crystal Structure of Ba17Sm10Cl64

✍ Scribed by Guo Liu; Harry A Eick

• Publisher: Elsevier Science
• Year: 1999
• Tongue: English
• Weight: 165 KB
• Volume: 146
• Category: Article
• ISSN: 0022-4596
• DOI: 10.1006/jssc.1999.8317

✦ Synopsis

The structure of Ba 17 Sm 10 Cl 64 , prepared by solvolytic extraction of a program-cooled 1:1 BaCl 2 :SmCl 3 molar mixture sealed in a quartz tube and heated to 7503C, was determined from single-crystal X-ray di4raction data. The compound exhibits cubic symmetry, space group Pa3 (No. 205) with a ‫؍‬ 21.366(2) A > and Z ‫؍‬ 4. Re5nement e4ected with I'2 (I) yielded R 1 ‫؍‬ 0.0926 and wR 2 ‫؍‬ 0.216. One Ba atom is 12-coordinated by Cl atoms in a distorted icosahedral arrangement; the three other Ba atoms are 10-coordinated in a distorted bicapped cubic arrangement. There are two Sm atom sites. The coordination around one Sm atom is best described as square antiprismatic, but one Sm+Cl distance is too long for e4ective bonding. The other Sm atom site, occupied statistically by 1 3 Ba and 2 3 Sm atoms, is 9-coordinated by Cl atoms in a monocapped square antiprismatic arrangement. The two types of Sm sites combine to form an M 6 Cl 37 cuboctahedral cluster of the composition BaSm 5 Cl 37 . It is shown that the c phase identi5ed previously in the Yb+F and related 6uoride systems is probably isostructural with Ba 17 Sm 10 Cl 64 .