X-RAY DIFFRACTION STUDY OF THE MODULATED STRUCTURE IN SUPERCONDUCTING SINGLE-CRYSTAL Bi2Sr2CaCu2Oy

1988 ◽  
Vol 02 (08) ◽  
pp. 985-991 ◽  
Author(s):  
X. CHU ◽  
Z.H. MAI ◽  
Y.F. YAN ◽  
J.H. WANG ◽  
D.N. ZHENG ◽  
...  

X-ray precession technique1 has been utilized to study the reciprocal space of the superconducting single crystal Bi 2 Sr 2 CaCu 2 O y. An average structure with space group of Pnnn and a real structure with the superspace group of [Formula: see text] or [Formula: see text] have been found for this one dimensional modulated incommensurate material. As well, a basic structure with the space group of Fmmm is derived from the experimental data.

2005 ◽  
Vol 61 (4) ◽  
pp. 361-366 ◽  
Author(s):  
Siegbert Schmid ◽  
Trixie Wagner

Members of the AMOB2O5 (A = K, Rb, Cs, Tl; M = Nb, Ta) family of compounds can be described as modulated structures with a single superspace group and very similar modulation functions. Single-crystal X-ray diffraction data (Mo Kα radiation) are used to solve and refine the structure of KNbOB2O5 in these terms for the first time. The average structure is solved and refined in the space group Pmn21. Subsequently, the atomic modulation functions are determined using JANA2000 and superspace-group symmetry Pmn21(0,0.375,0)s. The commensurately modulated structure is finally refined as a superstructure in the space group Pbn21 using SHELXS97 converging to R 1 = 0.024.


1986 ◽  
Vol 39 (1) ◽  
pp. 159 ◽  
Author(s):  
MI Bruce ◽  
DN Duffy ◽  
MG Humphrey

The reaction between Co2(CO)8 and Fe(C2Ph)(CO)2(η-C5H5) gave the title complex in 44% yield. The molecular structure was determined from a single-crystal X-ray diffraction study, and consists of the transition metal acetylide acting as a conventional μ- alkyne ligand to a Co2(CO)6 unit. Crystals are monoclinic, space group P21/n, with a 11.610(8), b 14.657(4), c 12.526(6)Ǻ, β 90.30(5)°, and Z 4; 1683 independent data were refined to R 0.080, Rw 0.087.


Author(s):  
Paolo Lotti ◽  
G. Diego Gatta ◽  
Marco Merlini ◽  
Hanns-Peter Liermann

AbstractThe high-pressure behavior of a synthetic mordenite-Na (space group:


1982 ◽  
Vol 37 (6) ◽  
pp. 581-586 ◽  
Author(s):  
R. Caminiti ◽  
G. Marongiu ◽  
G. Paschina

Abstract X-ray single crystal analysis of MnSO4·5H2O shows that the manganese atoms are octahedrally coordinated by oxygen atoms, four of which belong to water molecules and two to sulphate groups. A model derived from the crystal structure was fitted to the X-ray scattering intensities from aqueous MnSO4. Good agreement with experimental data is achieved using a model in which Mn(H2O)6-z(OSO3)z+2-2z interacts with about ten water molecules and each sulphate ion with about seven water molecules.


Author(s):  
Hiroki Okudera ◽  
Akira Yoshiasa ◽  
Yuji Masubuchi ◽  
Mikio Higuchi ◽  
Shinichi Kikkawa

AbstractIn this paper we report single crystal X-ray diffraction study of an oxide-ion-conductor Nd


1982 ◽  
Vol 60 (11) ◽  
pp. 1333-1338 ◽  
Author(s):  
P. Michael Boorman ◽  
Penelope W. Codding ◽  
K. Ann Kerr ◽  
Kelly J. Moynihan ◽  
Vikram D. Patel

The complex (Me2S)Cl2W(μ-S)(μ-SEt)2WCl2(Me2S), 1, has been prepared by reaction of [WCl4(Me2S)2] with 1 mol-equiv. of SiMe3(SEt) in CH2Cl2 solution. A single-crystal X-ray diffraction study shows that the molecule has a confacial bioctahedral structure with a W—W bond length of 2.526(2) Å. The structure was solved by heavy atom methods and refined to R = 0.061 and Rw = 0.061 for 2715 reflections with I ≥ 3σ(1). Crystals of 1 are triclinic, space group [Formula: see text], with a = 9.661(1), b = 10.695(1), c = 13.253(4) Å, α = 61.84(2), β = 66.98(2), and γ = 66.44(1)°, Z = 2.Reaction of 1with 2 mol-equiv. of Ph4PCl in CH2Cl2 solution yields (Ph4P)2[Cl3W(μ-S)(μ-SEt)2WCl3], 2. Crystals of 2 are triclinic, space group [Formula: see text], with a = 10.153(1), b = 13.043(1), c = 21.876(3) Å, α = 95.16(1), β = 96.48(2), and γ = 108.90(1)°, Z = 2. The structure was refined to R = 0.041, Rw = 0.048 for 2384 reflections with I ≥ 3σ(1); 2 also has a confacial bioctahedral structure with a W—W bond length of 2.522(1) Å.


Crystals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 614 ◽  
Author(s):  
David Prior ◽  
Miguel Cortijo ◽  
Rodrigo González-Prieto ◽  
Santiago Herrero ◽  
Reyes Jiménez-Aparicio ◽  
...  

In this article, we describe the preparation of anionic heteronuclear one-dimensional coordination polymers made by dirhodium paddlewheels and tetracyanido-metallatate building blocks. A series of complexes of (PPh4)2n[{Rh2(µ-O2CCH3)4}{M(CN)4}]n (M = Ni (1), Pd (2), Pt (3)) formulae were obtained by reaction of [Rh2(μ-O2CCH3)4] with (PPh4)2[M(CN)4] in a 1:1 or 2:1 ratio. Crystals of 1−3 suitable for single crystal X-ray diffraction were grown by slow diffusion of a dichloromethane solution of the dirhodium complex into a chloroform solution of the corresponding tetracyanido–metallatate salt. Compounds 1 and 2 are isostructural and crystallize in the triclinic P-1 space group, while compound 3 crystallizes in the monoclinic P21/n space group. A detailed description of the structures is presented, including the analysis of the packing of anionic chains and PPh4+ cations.


1986 ◽  
Vol 64 (1) ◽  
pp. 174-179 ◽  
Author(s):  
Michael D. Fryzuk ◽  
May-Ling Jang ◽  
Terry Jones ◽  
Frederick W. B. Einstein

The reaction of phenol with the binuclear rhodium hydride [{(i-Pr)2PCH2CH2P(i-Pr)2}Rh]2(μ-H)2 generates [{(i-Pr)2PCH2CH2P(i-Pr)2}Rh]2(μ-H)(μ-OC6H5), 2, which was characterized by both solution spectroscopic techniques and a single crystal X-ray diffraction study. The structure was solved using Patterson and Fourier methods and refined to R = 0.019 (Rw = 0.027) for 6062 reflections; crystals of the compound are triclinic, space group [Formula: see text], with a = 9.018(2), b = 12.988(2), c = 17.558(3) Å, α = 99.42(1), β = 92.62(2), γ = 91.85(2)°, and Z = 2. Further reaction with excess phenol leads to the mononuclear complex (η5-C6H5O)Rh{(i-Pr)2PCH2CH2P(i-Pr)2}•2C6H5OH, which contains two phenol units hydrogen bonded to the oxygen of the η5-cyclohexy]dienylone ligand. The presence of the bridging phenoxide ligand in 2 results in reduced reactivity as compared to the starting binuclear hydride dimer.


2003 ◽  
Vol 56 (7) ◽  
pp. 671 ◽  
Author(s):  
Hong-Bo Liu ◽  
Shu-Yan Yu ◽  
Hui Huang ◽  
Zhong-Xing Zhang

Two infinite complexes {[Cu2(O2CCH3)4](3-tpt)(CH3OH)2}∞ (1) and {[Cu2(O2CPh)4](3-tpt)(C6H6)1.5}∞ (2) were obtained by reactions of 2,4,6-tris(3′-pyridyl)-1,3,5-triazine (3-tpt) with Cu2(O2CCH3)4 and Cu2(O2CPh)4, respectively, which have been structurally established by single-crystal X-ray diffraction. Complex (1) consists of one-dimensional zig-zag chains in its solid state, which can encapsulate methanol molecules; complex (2) consists of one-dimensional helical chains in its solid state, providing large channels which can selectively enclathrate benzene molecules. (1) crystallizes in the monoclinic space group P21/c with a 8.2892(4), b 22.8479(8), c 16.9258(10) Å, β 99.1480(10)°, V 3164.8(3) Å3, and Z 4; (2) crystallizes in the triclinic space group P1 with a 10.7641(8), b 12.0908(8), c 18.9039(12) Å, α 82.514(3)°, β 85.268(2)°, γ 79.746(4)°, V 2395.9(3) Å3, and Z 2. The inclusion selectivity toward aromatic molecules was discussed.


2010 ◽  
Vol 65 (4) ◽  
pp. 528-532 ◽  
Author(s):  
Olaf Reckeweg ◽  
Armin Schulz ◽  
Brian Leonard ◽  
Francis J. DiSalvo

The unit cell of Na[OCN] has been determined on single crystals at 170 K to have rhombohedral symmetry with the lattice parameters a = 356.79(10) and c = 1512.3(5) pm (hexagonal setting). According to the only model for which a converging refinement could be achieved, Na[OCN] crystallizes isopointal to β -NaN3 in the space group R¯3m (no. 166, Z = 3) with a statistically disordered [OCN]− anion. The positional coordinates and displacement parameters could not be separated for the O and N end atoms of the triatomic anion. The vibrational spectra show the frequencies typical for an [OCN]− moiety with Fermi resonance between the 2δ and the νsym vibrations for which the undisturbed frequencies were calculated.


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