论文信息 - Das Lanthaniodidethanid o‐La5I9(C2) – Die orthorhombische Hochtemperaturmodifikation

Das Lanthaniodidethanid o‐La5I9(C2) – Die orthorhombische Hochtemperaturmodifikation

The Lanthanumiodideethanide o-La5I9(C2) – The Orthorhombic High Temperature Modification o-La5I9(C2) is synthesized by reaction of LaI3, La metal and graphite powder in sealed Ta containers at 850 °C < T < 900 °C. It crystallizes in the orthorhombic space group Pbca with a = 8.0247(16) A, b = 16.887(3) A, c = 35.886(7) A. o-Ce5I9(C2) is isotypic with the lattice parameters a = 7.9284(4) A, b = 16.714(1) A, c = 35.530(3) A. o-La5I9(C2) transforms at 800 °C to the triclinic low temperature modification t-La5I9(C2). The transformation is reversible. The La atoms form trigonal bipyramids centered by C2 groups. These units are connected by iodine atoms above the faces (f), edges (e) and corners according to La5(C2)I(f)iI(e)i−i2/2I(e)i−a7/2I(e)a−i7/2. The C-C distance in the C2 unit is 1.45(2) A. The crystals with greenish luster are moisture sensitive.

A. Simon | C. Hoch | H. Mattausch

[1] A. Simon,et al. Lanthanides as d Metals , 2006 .

[2] A. Simon,et al. Drei neue Ethanidiodide des Lanthans: La5I9(C2), La6I10(C2) und La10I15(C2)2† , 2005 .

[3] A. Simon,et al. The Layered Lanthanum Carbide Halide Superconductors La2C2(X,X‘)2 (X,X‘ = Cl, Br, I): Neutron Powder Diffraction Characterization and Electronic Properties , 1999 .

[4] J. Corbett. Diverse solid-state clusters with strong metal–metal bonding. In praise of synthesis , 1996 .

[5] G. Meyer,et al. Trigonal-bipyramidale Cluster mit interstitiellen C2-Hanteln in den Chloriden K[M5(C2)]Cl10 (M = La, Ce, Pr) und Rb[M5(C2)]Cl10 (M = Pr, Nd) , 1994 .

[6] G. Meyer,et al. Der erste trigonal‐bipyramidale Cluster mit interstitieller C2‐Hantel in Rb[Pr5(C2)}Cl10] , 1993 .

[7] G. Meyer,et al. The First Trigonal‐Bipyramidal Cluster with an Interstitial C2 Unit: [Rb{Pr5(C2)}Cl10] , 1993 .

[8] G. Miller,et al. Chapter 100 Metal-rich halides: Structure, bonding and properties , 1991 .

[9] A. Simon,et al. Gd10C4Cl18 und Gd10C4Cl17, zwei Seltenerdmetall‐Clusterverbindungen mit interstitiellen C2‐Gruppen , 1982 .

[10] H. Schäfer,et al. Metall‐Metall‐Bindungen bei niederen Halogeniden, Oxyden und Oxydhalogeniden schwerer Übergangsmetalle Thermochemische und strukturelle Prinzipien , 1964 .

[11] M. Baudler,et al. Handbuch der präparativen anorganischen Chemie , 1954 .