Dicationic Methyl Complexes of the Rare-Earth Elements

2014 ◽  
Vol 69 (3) ◽  
pp. 327-331 ◽  
Author(s):  
Anja Nieland ◽  
Andreas Mix ◽  
Beate Neumann ◽  
Hans-Georg Stammler ◽  
Norbert W. Mitzel

The reactions of Ln(AlMe4)3 (Ln=Ho, Tm) with the crown ether [12]crown-4 yield dicationic methyl rare-earth metal complexes [LnMe([12]crown-4)2][AlMe4]2 (Ln=Ho (1), Tm (2)). The reaction of La(AlMe4)3 with [18]crown-6 in thf affords [LaMe([18]crown-6)(thf)2][AlMe4]2 (3). The compounds have been characterized by X-ray diffraction, 1 and 3 additionally by elemental analyses as well as by 1H and 27Al, and 3 also by 13C NMR spectroscopy

2019 ◽  
Vol 48 (17) ◽  
pp. 5614-5620
Author(s):  
Joshua Greenough ◽  
Zheng Zhou ◽  
Zheng Wei ◽  
Marina A. Petrukhina

Two new organometallic cyclooctatetraenyl complexes of the type [M2(COT)3(THF)2] (M = Y and La) have been prepared, using optimized synthetic procedures, and fully characterized by X-ray diffraction analysis, IR and 1H NMR spectroscopies.


2020 ◽  
Vol 76 (9) ◽  
pp. 1447-1453
Author(s):  
Chad T. Palumbo ◽  
Christopher M. Kotyk ◽  
Joseph W. Ziller ◽  
William J. Evans

Studies of the coordination chemistry between the diphenylamide ligand, NPh2, and the smaller rare-earth Ln III ions, Ln = Y, Dy, and Er, led to the structural characterization by single-crystal X-ray diffraction crystallography of both solvated and unsolvated complexes, namely, tris(diphenylamido-κN)bis(tetrahydrofuran-κO)yttrium(III), Y(NPh2)3(THF)2 or [Y(C12H10N)3(C4H8O)2], 1-Y, and the erbium(III) (Er), 1-Er, analogue, and bis[μ-1κN:2(η6)-diphenylamido]bis[bis(diphenylamido-κN)yttrium(III)], [(Ph2N)2Y(μ-NPh2)]2 or [Y2(C12H10N)6], 2-Y, and the dysprosium(III) (Dy), 2-Dy, analogue. The THF ligands of 1-Er are modeled with disorder across two positions with occupancies of 0.627 (12):0.323 (12) and 0.633 (7):0.367 (7). Also structurally characterized was the tetrametallic ErIII bridging oxide hydrolysis product, bis(μ-diphenylamido-κ2 N:N)bis[μ-1κN:2(η6)-diphenylamido]tetrakis(diphenylamido-κN)di-μ3-oxido-tetraerbium(III) benzene disolvate, {[(Ph2N)Er(μ-NPh2)]4(μ-O)2}·(C6H6)2 or [Er4(C12H10N)8O2]·2C6H6, 3-Er. The 3-Er structure was refined as a three-component twin with occupancies 0.7375:0.2010:0.0615.


1989 ◽  
Vol 151 ◽  
Author(s):  
W. R. Bennett ◽  
R. F. C. Farrow ◽  
S. S. P. Parkin ◽  
E. E. Marinero

ABSTRACTWe report on the new epitaxial system LaF3/Er/Dy/Er/LaF3/GaAs (111) grown by molecular beam epitaxy. X-ray diffraction studies have been used to determine the epitaxial relationships between the rare earths, the LaF3 and the substrate. Further studies of symmetric and asymmetric reflections yielded the in-plane and perpendicular strain components of the rare earth layers. Such systems may be used to probe the effects of magnetoelastic interactions and dimensionality on magnetic ordering in rare earth metal films and multilayers.


2015 ◽  
Vol 11 ◽  
pp. 1-8 ◽  
Author(s):  
Gert Kollenz ◽  
Ralf Smounig ◽  
Ferdinand Belaj ◽  
David Kvaskoff ◽  
Curt Wentrup

The structures of two derivatives of the bisdioxine diisocyanate 1, the bisurea 4 and the biscarbamate 5, are established by X-ray crystallography and DFT calculations. These compounds possess endo,endo structures, in the case of the bisurea 4 with two nearly parallel pendant chains. The X-ray structures are reproduced very well by DFT calculations. Similar endo,endo conformations are calculated for the bisamide crown ether derivatives 7, where two proximate and nearly parallel crown ether units endow the molecules with a claw-like molecular cleft or tweezer structure as evidenced by an enhanced ability to extract some alkali, alkaline earth and rare earth metal ions.


2011 ◽  
Vol 236-238 ◽  
pp. 3041-3045 ◽  
Author(s):  
Ling Mei Yang ◽  
Peng Mei Lv ◽  
Zhen Hong Yuan ◽  
Wen Luo ◽  
Zhong Ming Wang ◽  
...  

Fe(II)-Zn-based double metal cyanide complex catalysts modified with rare earth metal or transition metal promoters(lanthanum, cerium, zirconium, manganese) for the production of biodiesel were prepared, and the effect of the addition of different metal promoters on the characteristics of the catalyst was studied by using X-ray diffraction (XRD), BET, ICP and Infrared techniques .The experiment results show that the Fe(II)-Zn-based catalyst promoted with 1 wt.% of La(NO3)3·nH2O exhibits the highest catalytic activity for the reaction, being as high as 99.3% of the yield of fatty acid methyl esters (FAME). Fe(II)-Zn-based catalysts have a tentative molecular formula: K2Zn3[Fe(CN)6]2·xH2O· (t-BuOH), where x=3-9 determined by using elemental analysis and ICP. It has been shown that the molecular formula of Fe(II)-Zn-based double metal cyanide complex catalysts did not change by adding 1 wt.% of rare earth metal or transition metal promoters. X-ray diffraction and BET results showed that Fe(II)-Zn-based catalysts with 1 wt.% of metal promoters salts exhibit smaller particle size, higher surface area than the Fe(II)-Zn catalyst ,which may be related to the higher activity of the catalysts.


2018 ◽  
Vol 233 (9-10) ◽  
pp. 607-613 ◽  
Author(s):  
Sebastian Stein ◽  
Rainer Pöttgen

Abstract Six new rare earth metal-rich intermetallic compounds RE9CoMg4 with RE=Y, Dy, Ho, Er, Tm and Lu were synthesized by induction-melting the elements in sealed niobium ampoules followed by annealing in muffle furnaces. The structures of Y9CoMg4 and Tm8.56CoMg4.44 were refined from single-crystal X-ray diffraction data: P63/mmc, a=965.65(6), c=971.07(5) pm, wR2=0.0599, 614 F2 values, 20 variables for Y9CoMg4 and a=945.20(4), c=953.11(5) pm, wR2=0.0358, 585 F2 values, 21 variables for Tm8.56CoMg4.44 (a small homogeneity range results from Tm/Mg mixing). The RE9CoMg4 phases crystallize with a coloring variant of the aristotype Co2Al5. The striking structural motif is a hexagonal rod packing of rows of corner- and face-sharing tetrahedral Mg4 clusters with Mg–Mg distances ranging from 304 to 317 pm in Y9CoMg4. These rows are similar to the hexagonal Laves phases REMg2. The space between the rows is filled with rows of face-sharing Co@Y6 trigonal prisms (TP) and empty Y6 octahedra (O) in the sequence –TP–O–O–. The many isopointal coloring variants of the aristotype Co2Al5 are briefly discussed.


2002 ◽  
Vol 12 (9) ◽  
pp. 347-350
Author(s):  
S. van Smaalen ◽  
P. Daniels ◽  
F. Galli ◽  
R. Feyerherm ◽  
E. Dudzik ◽  
...  

X-ray diffraction with synchrotron radiation has been used to study the phase transitions in compounds M5Ir4Si10 with M a rare-earth metal. For M = Er, Ho and Er0.84Lu0.16 phase transitions have been found towards a combined commensurate/incommensurate state, that locks into a commensurate state at lower temperatures. For M = Lu and Er0.66Lu0.34 there is a single transition towards a commensurate state. The results are interpreted in terms of commensurate structural transitions that induce incommensurate CDWs.


2018 ◽  
Vol 73 (11) ◽  
pp. 927-942 ◽  
Author(s):  
Frank Stegemann ◽  
Oliver Janka

AbstractThe rare earth metal-rich cobalt and nickel aluminium compounds with the general compositions RE6Co2Al (RE=Sc, Y, Nd, Sm, Gd–Tm, Lu) and RE6Ni2.25Al0.75 (RE=Y, Gd–Tm, Lu) have been synthesised from the elements by arc-melting, followed by annealing. Single-crystal X-ray diffraction experiments on Y6Co2.02(1)Al0.98(1) (Ho6Co2Ga type; Immm; a=944.1(2), b=952.4(2), c=999.0(2) pm; wR2=0.0452, 1123 F2 values, 35 variables) and Y6Ni2.26(1)Al0.74(1) (Ho6Co2Ga type; Immm; a=938.30(5), b=959.45(5), c=996.05(6) pm; wR2=0.0499, 1131 F2 values, 35 variables) revealed that the compounds form solid solutions according to the general formula RE6(Co/Ni)2+xAl1−x with different homogeneity ranges. The compounds of the Ni series can be obtained in X-ray pure form only with the nominal composition RE6Ni2.25Al0.75. A significant increase of the U22 component of the anisotropic displacement parameters of the Co/Ni2 atoms (4g site) was observed that requires a description of the structure with a split-position model at RT. Further investigations by low temperature (90 K) single-crystal X-ray diffraction experiments of Y6Co2.02(1)Al0.98(1) showed a significant decrease of U22. Magnetic measurements were conducted on the X-ray pure members of the RE6Co2Al (RE=Y, Dy–Tm, Lu) series. Antiferromagnetic ordering was observed for the members with unpaired f electrons with Néel temperatures up to TN=48.0(1) K and two spin reorientations for Dy6Co2Al.


2017 ◽  
Vol 73 (2) ◽  
pp. 121-125 ◽  
Author(s):  
Griffen Desroches ◽  
Svilen Bobev

The ternary phase hexacerium tricosacadmium telluride, Ce6Cd23Te, was synthesized by a high-temperature reaction of the elements in sealed Nb ampoules and was structurally characterized by powder and single-crystal X-ray diffraction. The structure, established from single-crystal X-ray diffraction methods, is isopointal with the Zr6Zn23Si structure type (Pearson symbolcF120, cubic space groupFm-3m), a filled version of the Th6Mn23structure with the same space group and Pearson symbolcF116. Though no Cd-containing rare-earth metal binaries are known to form with this structure, it appears that the addition of small amounts of ap-block element allows the formation of such interstitially stabilized ternary compounds. Temperature-dependent direct current (dc) magnetization measurements suggest local-moment magnetism arising from the Ce3+ground state, with possible valence fluctuations at low temperature, inferred from the deviations from the Curie–Weiss law.


1989 ◽  
Vol 69 (2) ◽  
pp. 191-194 ◽  
Author(s):  
A. Winiarski ◽  
A. Winiarska ◽  
A. Chełkowski

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