Yttrium crystal structure

The B-type oxyorthosilicate is also monoclinic with a space group of B2/b and there are pight formula units in a unit cell approximately double the size of the A-type ceU. This structure type is characteristic of the heavier lanthanides (Dy - Lu) and yttrium. Crystal structures have been determined for the yttrium and ytterbiiun... 

The tendency to form ate complexes observed for yttrium is also seen in the preparation of a novel zirconium alkynyl complex. Reaction of Zr(Por)Cl2 (Por = OEP or TPP) with either two or three equivalents of LiC=CR (R = Ph or SiMe ) gives the trisalkynyl complexes Zr(Por)(C=CR)3Li(TFIF). An X-ray crystal structure of Zr(OEP)(C=CPh)2Li(THF) shows that all three alkynyl ligands are on... 

Yttrium-barium-copper oxide compounds YBa2Cu306+x (x = 0.6-1), generally abbreviated to 123, with a Tc of 90K which is above the temperature of liquid nitrogen, are of great importance (2). As noted earlier, Tc is governed principally by the crystal structure... 

The crystal structure of the 1-2-3 superconductor, YBazCusOy- is depicted in Figure 10.8. Figure 10.8(a) depicts only the positions of the metal atoms. If we discuss it in terms of the perovskite structure ABO3, where B=Cu, the central section is now an A-type perovskite unit cell and above and below it are also A-type perovskite unit cells with their bottom and top layers missing. This gives copper atoms at the unit cell corners and on the unit cell edges at fractional coordinates A and Ys. The atom at the body-centre of the cell (i.e., in the centre of the middle section) is yttrium. The atoms in the centres of the top and bottom cubes are barium... 

A breakthrough in superconductor technology came with the discovery24 of yttrium barium copper oxide, YBa2Cu307, whose crystal structure is shown here. When heated, the material readily loses oxygen atoms from the Cu-O chains, and any composition between YBa2Cu307 and YBa2Cu3Ob is observable. 

Samarskite.—TYna tantaloniobate mineral has a widely varying composition, and was first discovered in the Urals. The presence of uranium in this mineral renders it radioactive. The presence of lead and helium has been detected. The ratio of lanthanides to yttrium is approximataly 1 6. In its crystal structure samarskite resembles yttrotantalite. Native crystals are brown, or velvet black, and become yellow orange when crushed showing pleochroism. 

The synthesis and X-ray crystal structure of (Me3SiCp)Y[(/r-OrBu)(/z-Me)AlMe2]2 shows a heterometallic bridge stabilization and an unusual tetragonal pyramidal geometry for yttrium [135]. 

Figure 3.10 Structures of (a) [YL3(H20)2]4 (HL = -hydoxybenzoic acid) and (b) [LuL4]4 (HL = acetic acid) [RE, black O, grey C, white H, omitted], (Redrawn from the CIF files of M.S. Khiyalov et al, Crystalline and molecular structure of (p-hydroxybenzoato)yttrium(III), Koordi-natsionnaya Khimiya (Coordination Chemistry) (in Russian), 7 (8), 1255-1261, 1981 [49] and A. Lossin and G. Meyer, Ternary acetates of the lanthanides with cesium dimers in CsLu(CH3COO)4 and trimers in Cs2[Lu3(CH3COO)io(OH)(H20)]. Synthesis, crystal structures, thermolysis, Zeitschriftfur Anorganische undAllgemeine Chemie, 619 (8), 1465-1473, 1993 [52].)...

Wenk, H.R. (1981) The crystal structures of yttrium, holmium and erbium formate dihydrates. Zeitschrift fuer Kristallographie, 154 (1-2), 137-145. 

Grillone, M.D., Benetollo, E, and Bombieri, G. (1991) The yttrium chloride-1,10-phenanthroline interaction synthesis and x-ray crystal structure of the complex [Y(0H)(H20)2(phen)2]2Cl4-2(phen)-Me0H. Polyhedron, 10,2171-2177. 

Argonne was the first lab to report the growth, crystal structure, and superconducting transition temperature of a single crystal of the yttrium compounds. The first ones were only 0.3 millimeters long, but they packed a wallop. 

The first confirmation of cis-binding of cations by the amide functions came from an X-ray crystal structure of the complex between 38 (m, n = 2) and yttrium perchlorate [65]. The stoichiometry was 1 2 1 ligand H2O) and the seven-... 

The materials derived from YBa2Cu307 by replacing yttrium with other rare earth elements (lutetium, ytterbium, thulium, erbium, hohnium, dysprosium, gadolinium, europium, samarium, neodymium, lanthanum) are also superconductors, with r, s of 88 to 96 K. The crystal structures of RBa2Cu307 are almost the same as those of YBa2Cu307. The lattice constant is slightly different for the different ionic radii of the rare earth elements, and yet their chemical and physical properties are almost the same as those of YBa2Cu307. 

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