13818-75-2Relevant articles and documents
Condensed double-chain cluster complexes with seven-coordinate endohedral iridium atoms in {Ir2Gd5}Br5
Bruehmann, Matthias,Meyer, Gerd
, p. 1257 - 1260 (2012)
The new condensed double-chain cluster complex compound {Ir 2Gd5}Br5 was obtained from a reaction of GdBr3 with metallic gadolinium and iridium at elevated temperatures. The thin black needles crystallize with the orthorhombic crystal system, space group Pnma(no. 62); a = 1255.4(1) pm, b = 414.05(3) pm, c = 2633.8(3) pm,Z = 4, R1/wR2 = 0.0504/0.0346 for all data. Monocapped trigonal prisms of gadolinium atoms with endohedral iridium atoms are connected by common rectangular faces to chains and further by edges to double chains, which form a herringbone arrangement. The double chains are coordinated by bromido ligands and are connected in accord with the formulation {Ir2Gd 5}Br4/2iBr2/3i(e)Br 1/3i(f)Br2/2i-i(e/f)Br 1/2i-aBr1/2a-i. Copyright
Structural characterization of methanol substituted lanthanum halides
Boyle, Timothy J.,Ottley, Leigh Anna M.,Alam, Todd M.,Rodriguez, Mark A.,Yang, Pin,Mcintyre, Sarah K.
, p. 1784 - 1795 (2010/07/03)
The first study into the alcohol solvation of lanthanum halide [LaX3] derivatives as a means to lower the processing temperature for the production of the LaBr3 scintillators was undertaken using methanol (MeOH). Initially the de-hydration of {[La(μ-Br)(H2O)7](Br)2}2 (1) was investigated through the simple room temperature dissolution of 1 in MeOH. The mixed solvate monomeric [La(H2O)7(MeOH)2](Br)3 (2) compound was isolated where the La metal center retains its original 9-coordination through the binding of two additional MeOH solvents but necessitates the transfer of the innersphere Br to the outersphere. In an attempt to in situ dry the reaction mixture of 1 in MeOH over CaH2, crystals of [Ca(MeOH)6](Br)2 (3) were isolated. Compound 1 dissolved in MeOH at reflux temperatures led to the isolation of an unusual arrangement identified as the salt derivative {[LaBr2.75·5.25(MeOH)]+0.25 [LaBr3.25·4.75(MeOH)]-0.25} (4). The fully substituted species was ultimately isolated through the dissolution of dried LaBr3 in MeOH forming the 8-coordinated [LaBr3(MeOH)5] (5) complex. It was determined that the concentration of the crystallization solution directed the structure isolated (4 concentrated; 5 dilute) The other LaX3 derivatives were isolated as [(MeOH)4(Cl)2La(μ-Cl)]2 (6) and [La(MeOH)9](I)3·MeOH (7). Beryllium Dome XRD analysis indicated that the bulk material for 5 appear to have multiple solvated species, 6 is consistent with the single crystal, and 7 was too broad to elucidate structural aspects. Multinuclear NMR (139La) indicated that these compounds do not retain their structure in MeOD. TGA/DTA data revealed that the de-solvation temperatures of the MeOH derivatives 4-6 were slightly higher in comparison to their hydrated counterparts.
New layered germanide halides RE2GeX2 (RE = Y, Gd; X = Br, I)
Lukachuk, Mar'yana,Kremer, Reinhard K.,Mattausch, Hansjuergen,Simon, Arndt
, p. 3231 - 3235 (2008/10/09)
The title compounds were synthesized from RE, REX3, and Ge under an Ar atmosphere at 1200-1370 K. Y2GeI2 and Gd 2GeI2 crystallize in space group R3m with lattice constants a = 4.2135(3) and 4.2527(1) A and c = 31.480(2) and 31.657(1) A, respectively. Gd2GeBr2 crystallizes in two modifications, the 1T-type (space group P3m1; a = 4.1668(2) A, c = 9.8173(6) A) and the 3R-type (space group R3m; a = 4.1442(9) A, c = 29.487(7) A). The structural motifs of RE2GeX2 compounds are Ge-centered slightly distorted RE6 octahedra connected via their common edges and extending in the a and b directions. The resulting close-packed double layers are separated by halogen atoms. The electrical resistivity measurements revealed semiconductor behavior for Y 2GeI2 and Gd2GeI2 and a metal-semiconductor transition for 1T-Gd2GeBr2. Magnetic susceptibility and heat capacity measurements show long-range magnetic ordering for Gd2GeI2 and 1T-Gd2GeBr2 at ～15 and ～13 K, respectively.
