Synthesis and Single-Crystal X-ray Diffraction Examination of a Structurally Homologous Series of Tetracoordinate Heteroleptic Anionic Lanthanide Complexes:  Ln{N[Si(CH3)2CH2CH2Si(CH3)2]}3(μ-Cl)Li(L)3[Ln = Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb; (L)3= (THF)3, (Et2O)3, (THF)2(Et2O)]

2001 ◽  
Vol 40 (8) ◽  
pp. 1751-1755 ◽  
Author(s):  
Oliver Just ◽  
William S. Rees
1997 ◽  
Vol 53 (6) ◽  
pp. 861-869 ◽  
Author(s):  
C. D. Ling ◽  
J. G. Thompson ◽  
S. Schmid ◽  
D. J. Cookson ◽  
R. L. Withers

The structures of the layered intergrowth phases SbIIISb^{\rm V}_xAl-xTiO6 (x \simeq 0, A = Ta, Nb) have been refined by the Rietveld method, using X-ray diffraction data obtained using a synchrotron source. The starting models for these structures were derived from those of Sb^{\rm III}_3Sb^{\rm V}_xA 3−xTiO14 (x = 1.26, A = Ta and x = 0.89, A = Nb), previously solved by single-crystal X-ray diffraction. There were no significant differences between the derived models and the final structures, validating the approach used to obtain the models and confirming that the n = 1 and n = 3 members of the family, Sb^{\rm III}_nSb^{\rm V}_xA n−xTiO4n+2 are part of a structurally homologous series.


2003 ◽  
Vol 58 (5) ◽  
pp. 389-394 ◽  
Author(s):  
Alexander A. Trifonov ◽  
Mikhail N. Bochkarev ◽  
Herbert Schumann ◽  
Sebastian Dechert

Racemic trans-2-(9(H)-fluoren-9-yl)cyclohexanol, C13H9-cyclo-C6H10-OH (1), reacts with two equivalents of potassium naphthalenide in THF to give the dipotassium salt [C13H8-cyclo-C6H10-O]- K2(THF) (2). Recrystallization of 2 from pyridine affords the solvent free salt [C13H8-cyclo-C6H10- O]K2 (3). The reactions of LaI3(THF)4 with one equivalent of 2 or of YbI2(THF)2 with equimolar amounts of 2 produce the alkoxolanthanum diiodide (C13H9-cyclo-C6H10-O)LaI2(DME)2 (4) and the ytterbium dialkoxide (C13H9-cyclo-C6H10-O)2Yb(THF)0.5(5), respectively. [(Me3Si)2N]3Y reacts with three equivalents of 1 with elimination of hexamethyldisilazane and formation of the yttrium trialkoxide (C13H9-cyclo-C6H10-O)3Y (6). The compounds 2 to 5 were characterized by elemental analyses, 1H NMR, 13C NMR and IR spectra. The molecular structure of 4 was determined by single crystal X-ray diffraction.


Author(s):  
Aleksandra Deptuch ◽  
Teresa Jaworska-Gołąb ◽  
Joachim Kusz ◽  
Maria Książek ◽  
Keigo Nagao ◽  
...  

Structural characteristics of solid and liquid crystalline phases of 7OS5 (4-n-pentylphenyl-4′-n-heptyloxythiobenzoate), the achiral smectogenic mesogen with the shortest terminal carbon chain in the nOS5 homologous series, are studied by complementary methods. Simultaneously perfomed X-ray diffraction and differential scanning calorimetry occur to be a powerful tool to study metastable phases. The single crystal structure of a high-temperature phase, supercooled from the room temperature down to −183°C [orthorhombic crystal system; space group Pca21; a = 54.285 (5) Å, b = 5.5843 (3) Å, c = 14.841 (1) Å, Z = 8] is determined. Lamellar ordering of elongated molecules is stabilized by hydrogen bonds . Temperature dependence of unit-cell parameters in two crystal phases as well as structural parameters of liquid crystalline phases (smectic layer spacing, tilt angle, average distance between the long axes of molecules and correlation lengths) are determined by X-ray diffraction. The obtained results are compared with the data available for other compounds in the nOS5 homologous series.


2008 ◽  
Vol 64 (5) ◽  
pp. 521-526 ◽  
Author(s):  
Yuichi Michiue ◽  
Noboru Kimizuka ◽  
Yasushi Kanke

The structure of Ga2O3(ZnO)6 was determined using single-crystal X-ray diffraction techniques in the space group Cmcm. The metal ion sublattice resembles some of the Zn ions in the wurtzite ZnO structure. The oxygen ion sublattice in Ga2O3(ZnO)6 also resembles some of the O ions in ZnO. Structural relationships between Ga2O3(ZnO)6 and ZnO are discussed, illustrating the process for obtaining the centrosymmetric Ga2O3(ZnO)6 structure from the noncentrosymmetric ZnO. Structures of phases in the homologous series Ga2O3(ZnO) m are predicted on the basis of the structural data for Ga2O3(ZnO)6. The structures of even m are constructed by simply extending the structure units seen in Ga2O3(ZnO)6, while those of odd m consist of structure units which are of different types from those used for even m.


2012 ◽  
Vol 67 (6) ◽  
pp. 594-604 ◽  
Author(s):  
Frank Tappe ◽  
Falko M. Schappacher ◽  
Thorsten Langer ◽  
Inga Schellenberg ◽  
Rainer Pöttgen

Several samples of solid solutions RE16Rh11-xZx (RE = La, Ce, Pr, Nd, Sm; Z = Ga, Zn, Cd,In, Sn, Sb, Pb, Bi) were synthesized by high-frequency melting of the elements in sealed tantalum ampoules. The samples were characterized by powder X-ray diffraction, and the structures of eight compounds were refined on the basis of single-crystal X-ray diffractometer data. The compounds crystallize with a centrosymmetric variant (space group P4⁄mbm) of the Ca16Sb11 type (P4̄ 21m). The relation between both structure types is discussed on the basis of a group-subgroup scheme. Only for La16Rh8Sn3 we observed full rhodium-tin ordering. The striking structural motif is a chain of face-sharing square prisms (filled with tin) and anti-prisms (filled with rhodium). The La16Rh8Sn3 structure is closely related to the structure types W5Si3, Ca16Sb11, Y3Rh2, Sm26Co11Ga6, Pu31Pt20, and Yb36Sn23 and is the centrosymmetric n = 2 member of Parthé’s A5n+6B3n+5 series. 119Sn Mössbauer spectra resolved the two crystallographically independent tin sites of La16Rh8Sn3, while a Pr16Rh9Sb2 sample shows only a singlet in its 121Sb Mössbauer spectrum.


Author(s):  
J. M. Galbraith ◽  
L. E. Murr ◽  
A. L. Stevens

Uniaxial compression tests and hydrostatic tests at pressures up to 27 kbars have been performed to determine operating slip systems in single crystal and polycrystal1ine beryllium. A recent study has been made of wave propagation in single crystal beryllium by shock loading to selectively activate various slip systems, and this has been followed by a study of wave propagation and spallation in textured, polycrystal1ine beryllium. An alteration in the X-ray diffraction pattern has been noted after shock loading, but this alteration has not yet been correlated with any structural change occurring during shock loading of polycrystal1ine beryllium.This study is being conducted in an effort to characterize the effects of shock loading on textured, polycrystal1ine beryllium. Samples were fabricated from a billet of Kawecki-Berylco hot pressed HP-10 beryllium.


Author(s):  
Süheyla Özbey ◽  
F. B. Kaynak ◽  
M. Toğrul ◽  
N. Demirel ◽  
H. Hoşgören

AbstractA new type of inclusion complex, S(–)-1 phenyl ethyl ammonium percholorate complex of R-(–)-2-ethyl - N - benzyl - 4, 7, 10, 13 - tetraoxa -1- azacyclopentadecane, has been prepared and studied by NMR, IR and single crystal X-ray diffraction techniques. The compound crystallizes in space group


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