(thf)2Ln(Ge9{Si(SiMe3)3}3)2 (Ln = Eu, Sm): the first coordination of metalloid germanium clusters to lanthanides

2021 ◽  
Author(s):  
Andreas Schnepf ◽  
Svetlana Klementyeva ◽  
Claudio Schrenk ◽  
Marat M Khusniyarov ◽  
Minghui Zhang

We report the synthesis, structure and magnetic properties of the first rare earth complexes of metalloid group 14 clusters [(thf)2Ln(Ge9Hyp3)2] (Ln = Eu, Sm, Hyp = Si(SiMe3)3). X-ray crystallographic analysis...

2017 ◽  
Vol 46 (39) ◽  
pp. 13582-13589 ◽  
Author(s):  
Jani O. Moilanen ◽  
Akseli Mansikkamäki ◽  
Manu Lahtinen ◽  
Fu-Sheng Guo ◽  
Elina Kalenius ◽  
...  

The complexes [BQ(MCl2·THF3)2] (M = Y or Dy) possessing pentagonal bipyramidal environment around metal centers undergo significant thermal expansion as revealed by single-crystal X-ray and powder diffraction experiments.


2004 ◽  
Vol 61 (3) ◽  
pp. 405-410 ◽  
Author(s):  
Jianbin Tang ◽  
Liming Jiang ◽  
Weilin Sun ◽  
Zhiquan Shen

1999 ◽  
Vol 52 (6) ◽  
pp. 507 ◽  
Author(s):  
Lioubov I. Semenova ◽  
Allan H. White

Room-temperature single-crystal X-ray structure determinations are recorded for (hydrated) lanthanoid(III) nitrate/2,2′:6′,2″-terpyridine (‘tpy’) (1 : 1) complexes; all are of the form Ln(NO3)3/tpy/H2O(1 : 1 :x), [(tpy)Ln(O2NO)2(OH2)y](NO3)(.z H2O), and form two series of compounds. For Ln = La(-)Gd, the complexes are [(tpy)Ln(O2NO)2(OH2)3](NO3), the lanthanoid atom being ten-coordinate; crystals are triclinic, P 1, a ≈ 11·8, b ≈ 11·3, c ≈ 8·9 Å, α ≈ 75, β 69, γ ≈ 89°, Z = 2 f.u., conventional R on |F| 0·045, 0·062 for No 4513, 2710 independent ‘observed’ (I > 3σ(I)) diffractometer reflections for Ln = La, Gd respectively. For Ln = Tb(-)Lu, a different form is found: monoclinic, P 21/c, a ≈ 8·8, b ≈ 11·5, c ≈ 23·8 Å, β ≈ 111°, Z = 4, R 0·055, 0·037, 0·056 for No 2427, 3079, 1857 for Ln = Tb, Lu, Y respectively, the form of the complex being [(tpy)Ln(O2NO)2(OH2)2](NO3).2H2O, with nine-coordinate lanthanoid. Crystallization of the Ln = La adduct from methanol yields an adduct of La(NO3)3/tpy/MeOH (1 : 1 : 2) [(tpy)La(O2NO)3(HOMe)2] stoichiometry with 11-coordinate lanthanum. Crystals are triclinic, P 1, a 12·361(2), b 12·244(3), c 7·753(2) Å, α 96·56(2), β 103·22(2), γ 91·16(2)°, Z = 2, R 0·037 for No 6597.


1988 ◽  
Vol 41 (2) ◽  
pp. 155 ◽  
Author(s):  
DC Creagh

The experimental requirements for the investigation of the structural and magnetic properties of the light rare earth elements and their intermetallic compounds at synchrotron radiation sources are discussed. Experimental techniques considered include X-ray topography, energy dispersive X-ray diffraction and X-ray powder diffraction.


1999 ◽  
Vol 52 (6) ◽  
pp. 531 ◽  
Author(s):  
Lioubov I. Semenova ◽  
Peter C. Junk ◽  
Brian W. Skelton ◽  
Allan H. White

Room-temperature single-crystal X-ray structure determinations carried out on rare earth bromides crystallized from water at room temperature define three series of hydrates LnBr3.nH2O. For Ln = La, Ce, a heptahydrate phase (n = 7) is defined, triclinic P 1, a ≈ 8·6, b ≈ 9·4, c ≈ 8·3 Å, α ≈ 108, β ≈ 99, γ ≈ 72°, isomorphous with the array described for the ‘early’ (Ln = La-Pr) rare earth chlorides, being binuclear [(H2O)7Ln(-Br)2Ln(OH2)7] Br4, Z = 1 dimer; conventional R on |F| were 0·051, 0·042 for 2323, 3451 independent ‘observed’ (I > 3σ(I)) diffractometer reflections respectively. For Ln = Pr(-)Dy, a hexahydrate phase is defined, monoclinic P 2/n, a ≈ 10·0, b ≈ 6·8, c ≈ 8·2 Å, β ≈ 93·5°, Z = 2 f.u., isomorphous with the array defined for the heavier (Ln = Nd, Lu, Y) rare earth chlorides, being [(H2O)6LnBr2] Br, with R 0·029, 0·034 for No 1590, 1388 respectively. For Ln = Ho(-)Lu, Y, an octahydrate is defined for the first time, monoclinic P 21/n, a ≈ 8·1, b ≈ 16·0, c ≈ 10·1 Å, b ≈ 94·0°, Z = 4 f.u., a new array of the form [Ln(OH2)8] Br3 emerging, with R 0·061, 0·048, 0·042 for No 1191, 2402, 1674 respectively, the metal environment being square antiprismatic.


2010 ◽  
Vol 663-665 ◽  
pp. 76-79
Author(s):  
Zhen Feng Xu ◽  
Jun Liang ◽  
Juan Pei ◽  
Yan Yan Yin ◽  
Chang Li

New electron doped double perovskite compound (Sr2-xSmx) FeMoO6 (0≤x≤0.25) has been synthesized by solid-state reaction. Crystal structure and magnetic properties of the compounds have been investigated by X-ray powder diffraction (XRD) and magnetic measurements. XRD revealed that all the compounds were of single phase and belonged to a I 4/m lattice. The degree of cationic ordering on the B site was decreased pronouncedly by the electron doping. Different from the results of La- and Nd-doped Sr2FeMoO6, Curie temperature (TC) of (Sr2-xSmx) FeMoO6 decreased first with the doping and then increased beyond x = 0.15, indicating that steric effect was enhanced as the radius of rare-earth ions decreased.


1999 ◽  
Vol 52 (6) ◽  
pp. 601 ◽  
Author(s):  
Cameron J. Kepert ◽  
Peter C. Junk ◽  
Brian W. Skelton ◽  
Allan H. White

Room-temperature single-crystal X-ray studies carried out on trivalent rare earth sulfate hydrates, Ln2(SO4)3.xH2O, crystallized at local ambience suggest the following arrays to be prevalent. For Ln = La, the nonahydrate is found, hexagonal P 63/m, with conventional R on |F| 0·023 for No 1159 ‘observed’ (I >3σ(I)) diffractometer reflections (redetermination). Although for Ln = Ce a similar structure has been previously recorded, we have obtained that adduct as the monoclinic C 2/c, Z = 4, octahydrate, a phase also found for Ln = Lu and diverse representative intermediate lanthanoids: a ≈ 13·6, b ≈ 6·6, c ≈ 18·2 Å, β ≈ 102°; for Ln = Ce (redetermination), Dy, Yb (redetermination), Lu, R was 0·022, 0·035, 0·031, 0·024 for No 3279, 2127, 3008, 3325 respectively. The structures of two lower hydrates adventitiously obtained are also recorded: the pentahydrate for Ln = Ce, monoclinic C 2/c, a 15·741(3), b 9·632(3), c 10·358(3) Å, β 119·72(2)°, Z = 4, R 0·030 for No 3372 (a redetermination), and the trihydrate for Ln = Lu, orthorhombic Cmc21, a 13·527(5), b 18·415(5), c 9·242(7) Å, Z = 8, R 0·040 for No 1743. All structures are infinite polymeric arrays, the lanthanoid atoms being bridged by sulfate ions. Studies are also recorded for the ammonium/trivalent rare earth double sulfate tetrahydrate salts, (NH4)Ln(SO4)2.4H2O, for the (hitherto) extremal members Ln = La, Tb, which are isomorphous with the previously studied Ln = Sm monoclinic P 21/c, Z = 4 array, a ≈ 6·6, b ≈ 19, c ≈ 8·8 Å, β 97°; R 0·035, 0·037 for No 3631, 3337. The array is a two-dimensional polymer, parallel to the ac plane.


2011 ◽  
Vol 239-242 ◽  
pp. 3109-3112 ◽  
Author(s):  
Qin Zhang ◽  
Qing Wang ◽  
Zhen Cui Sun ◽  
Ke Yan Wang

Rare-earth-doped compounds (Sr1.85Ln0.15)FeMoO6(Ln=Sr, La, Ce, Pr, Nd, Sm and Eu) have been prepared by solid-state reaction. Crystal structure and magnetic properties were investigated by means of X-ray diffraction and magnetic measurements. All the samples are single phase and belong to the I4/m space group. Due to the competing contributions of electron doping and steric effects, the unit-cell volume of the doped compounds changes slightly and does not vary systematically with the ionic radius of the rare-earth ions. The temperature dependence of the magnetization of (Sr1.85Ln0.15)FeMoO6indicates that the Curie temperature of the doped compounds has increased upon doping, except for the Eu-doped compound.


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