ChemInform Abstract: New Layered Phases Achieved with Centered Zirconium Chloride Clusters. The Stoichiometry Zr6Cl16.
Abstract
Reaction of stoichiometric amounts of Zr powder, ZrCl4, NaCl, and Be flakes plus a 40% excess of NaCl at 800 °C (2 weeks) in a closed Ta container results in the new compound (I) in nearly quantitative yield.
ChemInform Abstract
Reaction of stoichiometric amounts of Zr powder, ZrCl4, NaCl, and Be flakes plus a 40% excess of NaCl at 800 °C (2 weeks) in a closed Ta container results in the new compound (I) in nearly quantitative yield. The different isostructural phases (II)-(IV) are obtained in a similar way from analogous reactions with CsCl, graphite, amorphous boron (yields ∼ 90%). (I) crystallizes in the orthorhombic system, space group Pccn, Z=4, while (II)-(IV) belong to the space group P21/n with Z=4. The two new Zr6Cl16Z structures are built up of puckered layers formed from Zr6Cl12 clusters with four Cla-a atoms bonded at Zr vertices serving to link adjacent clusters and two terminal Cla occupying the two remaining trans positions above and below the cluster sheet. The interstitial Z(Be, B, or C) occupies all cluster centers (2 ∞(Zr6Cl12Z)Cla-a 4/2Cla 2). The cations fractionally occupy irregular sites that are minimally 6- (Na+) or 7-coordinate (Cs+). Differences between (I) and (II)-(IV) exist with respect to cell symmetries, cation sties and, especially, relative cluster orientations and puckering of the layers.
