Cluster framework structures and relationships. Two compounds wit a new connectivity, K/sub 2/Zr/sub 6/Cl/sub 15/B and K/sub 3/Zr/sub 6/Cl/sub 15/Be

Journal Article · Tue Feb 16 23:00:00 EST 1988 · J. Am. Chem. Soc.; (United States)

DOI:https://doi.org/10.1021/ja00212a022· OSTI ID:5524201

Ziebarth, R P; Corbett, J D

The title compounds are obtained in high yield by reaction of stoichiometric quantities of ZrCl/sub 4/, KCl, powdered Zr, and the interstitial element B or Be in sealed tantalum containers at 800-850/sup 0/C for 2-3 weeks. The structures were established by single-crystal means to be orthorhombic for K/sub 2/Zr/sub 6/Cl/sub 15/B (Cccm, Z = 4, R = 3.3, R/sub w/ = 4.1) and monoclinic for K/sub 3/Zr/sub 6/Cl/sub 15/Be (C2/c, Z = 4, R = 4.8, R/sub w/ = 3.2). Both contain crisscrossing linear chains of trans-bridged clusters ...(Zr/sub 6/Cl/sub 12/B(Be))-Cl/sup a-a/... that are further interconnected by bent Cl/sup a-a/ bridges at the remaining four metal vertices. The low symmetry of one cation site in K/sub 2/Zr/sub 6/Cl/sub 15/B is noteworthy. The change of the interstitial atom in K/sub 3/Zr/sub 6/Cl/sub 15/Be forces an orthorhombic to monoclinic structural distortion in order to accommodate a third cation. The distortion is accomplished mainly by rotation of the linear chains in alternate directions, which splits the former low-symmetry cation site into two. The four distinct (M/sub 6/X/sub 12/)X/sup a-a//sub 6/2/ framework structures exhibited in the Ta/sub 6/Cl/sub 15/, CsNb/sub 6/Cl/sub 15/, K/sub 2/Zr/sub 6/Cl/sub 15/B, and Nb/sub 6/F/sub 15/ parent types are compared and systematized in terms of the three-dimensional cluster connectivity, ring size, and local Cl/sup a-a/ geometry. The choice among these for various M/sub x//sup I/(Zr/sub 6/Cl/sub 12/Z)Cl/sub 6/2/ compounds is evidently dictated by the size of the interstitial Z and the need to accommodate cations of various sizes and numbers, and the last is in turn largely governed by the electronic nature of the interstitial element Z.

• Research Organization: Iowa State Univ., Ames
• OSTI ID: 5524201
• Journal Information: J. Am. Chem. Soc.; (United States), Journal Name: J. Am. Chem. Soc.; (United States) Vol. 110:4; ISSN JACSA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360202* -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
ALKALI METAL COMPOUNDS
ALKALINE EARTH METAL COMPOUNDS
BERYLLIUM COMPOUNDS
BOND LENGTHS
BORIDES
BORON COMPOUNDS
CHLORIDES
CHLORINE COMPOUNDS
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
DATA
DIMENSIONS
EXPERIMENTAL DATA
HALIDES
HALOGEN COMPOUNDS
INFORMATION
INTERSTITIALS
LATTICE PARAMETERS
LENGTH
NUMERICAL DATA
POINT DEFECTS
POTASSIUM COMPOUNDS
SPACE GROUPS
STOICHIOMETRY
TRANSITION ELEMENT COMPOUNDS
ZIRCONIUM CHLORIDES
ZIRCONIUM COMPOUNDS