Low-Temperature Structure and Magnetic Properties of Tetraphenylarsonium Tetrachloronitridotechnetate(VI)

1996 ◽  
Vol 49 (5) ◽  
pp. 633 ◽  
Author(s):  
BN Figgis ◽  
PA Reynolds ◽  
FK Larsen ◽  
GA Williams ◽  
CD Delfs

The crystal structure of [As(C6H5)4] [TcNCl4] was determined at 120 K by X-ray diffraction and at 28 K by neutron diffraction. The crystals are tetragonal, space group P4/n, with a 1260.4(3) and c 773.2(2) pm at 120 K. The [TcNCl4]-anion possesses exact C4v symmetry, with Tc≡N distances of 160.3(2) and 162.5(4)pm at 120 and 28 K respectively. Magnetic susceptibilities were measured on single crystals from 300 to 4.5 K. The results indicate a well behaved S ½ system following the Curie-Weiss law with θ -0.13 K

1998 ◽  
Vol 53 (12) ◽  
pp. 1528-1530 ◽  
Author(s):  
Karna Wijaya ◽  
Oliver Moers ◽  
Armand Blaschette ◽  
Peter G. Jones

Abstract Benzo-18 -crown-6 -Acetonitrile (1/2), Crystal Structure Single crystals of the title complex resulted fortuitously during an attempt to co-crystallise MeN(SO2Me)2 with benzo-18-crown-6 from an MeCN solution at -30 °C. The crystal structure has been determined via data collection at -100 °C (monoclinic, space group P21/n, Z = 4). The nitrile molecules are located with their me­ thyl groups above and below the plane of the 18-membered crown ring, the Me hydrogen atoms being rotationally disordered about the MeCN axes; C(methyl)···O(crown) distances range from 309.4(3) to 384.9(3) pm.


1990 ◽  
Vol 04 (12) ◽  
pp. 791-794 ◽  
Author(s):  
YANG JI-LIAN ◽  
YE CHUN-TANG ◽  
ZHANG BAI-SHENG ◽  
LI JI-ZHOU ◽  
KANG JIAN ◽  
...  

The polycrystalline sample of (Bi–Pb)2Sr2Ca2Cu3O10 with Tc=107 K was prepared. The X-ray diffraction proved that the sample is single phase. The crystal structure study on the sample has been carried out by neutron diffraction. The result shows that its structure is tetragonal body-centre structure with space group of I4/mmm, containing a few oxygen atoms at 4e site in Bi–Pb layers.


1998 ◽  
Vol 53 (5-6) ◽  
pp. 634-636 ◽  
Author(s):  
Martina Näveke ◽  
Armand Blaschette ◽  
Peter G. Jones

Abstract The crystal structure of the known title compound was determined by low-temperature X-ray diffraction (orthorhombic, space group Pbcn, Z = 4). The molecule displays an unusually short O-N bond, a relatively long C-O bond and a moderately pyramidal O-NS2 skeleton (O-N 133.1, C-O 148.5 pm, sum of bond angles at N: 347.4°).


1997 ◽  
Vol 53 (1) ◽  
pp. 135-142 ◽  
Author(s):  
D. L. Corker ◽  
A. M. Glazer ◽  
J. Dec ◽  
K. Roleder ◽  
R. W. Whatmore

The crystal structure of the perovskite lead zirconate PbZrO3 has been redetermined using single-crystal X-ray diffraction (Mo Kα radiation, λ = 0.71069 Å). Single-crystal data at 100 K: space group. Pbam, a = 5.884 (1), b = 11.787 (3), c = 8.231 (2) Å, V = 570.85 Å3 with Z = 8, μ = 612.6 cm−1, D x = 8.06 Mg m−3, F(000) = 1168, final R = 0.033, wR = 0.061 over 555 reflections with I > 2σ(I). An investigation is made into previous contradicting reports of a possible disorder in the O atoms and their origin by examining the crystal pseudo-symmetry. Information distinguishing an ordered and disordered oxygen substructure is shown to reside in weak l odd reflections. Because of their extremely low intensities these reflections have not contributed sufficiently in previous X-ray structure investigations and hence, to date, conclusive evidence differentiating between ordered and disordered models has not been possible. By collecting single-crystal X-ray data at low temperature and by using exceptionally long scans on selected hkl, l odd, reflections, a new accurate structure determination is presented and discussed, showing the true ordered oxygen positions. Because of the large difference in scattering factors between lead and oxygen when using X-rays, a neutron diffraction Rietveld refinement using polycrystalline samples (D1A instrument, ILL, λ = 1.90788 Å) is also reported as further evidence to support the true ordered oxygen structure revealed by the low-temperature X-ray analysis.


2011 ◽  
Vol 66 (11) ◽  
pp. 1087-1091 ◽  
Author(s):  
Olaf Reckeweg ◽  
Francis J. DiSalvo

Colorless and transparent single crystals of Ba2H3I were obtained by reacting Ba with dried and sublimed NH4I in a 4 : 1 molar ratio in silica-jacketed Nb ampoules at 1100 K for 13 h. The crystal structure of the title compound was determined and refined by means of single-crystal X-ray diffraction. Ba2H3I crystallizes in a stuffed anti-CdI2 structure isotypic to Sr2H3I in the space group P3̄m1 (no. 164) with the lattice parameters a = 451.86(12) and c = 811.84(23) pm. The structural results for Ba2H3I are consistent with bond lengths and coordination geometries of related binary and ternary hydrides


1975 ◽  
Vol 30 (3-4) ◽  
pp. 277-278 ◽  
Author(s):  
Hans-L. Keller ◽  
Karl-H. Meier ◽  
Hk. Müller-Buschbaum

Single crystals of SrPbO3 could be prepared by oxygen-high-pressure-synthesis (PO2 > 3500 at, t = 450°C). Single crystal X-ray diffraction data confirm the space group D2h16-Pnma. SrPbO3 belongs to the orthorhombic distorted Perowskit type with a = 5.964, b = 8.320, c = 5.860 Å. The atomic positions were refined.


1991 ◽  
Vol 46 (3) ◽  
pp. 395-399 ◽  
Author(s):  
Ursula Bentrup ◽  
Werner Massa

Single crystals of [(CH3)4N]FeF4·H2O have been prepared from aqueous HF solution. The crystal structure was determined by X-ray diffraction: space group P1̄, Z = 2 (or 1 dimeric unit), a = 705.7(5), b = 818.5(8), c = 915.2(12) pm, α = 65.46(10)°, β = 82.90(9)°, γ = 72.76(7)°, R/wR = 0.047/0.021. The structure consists of centrosymmetrical dimeric anions [Fe2F8(H2O)2]2- with fluorine double bridges and is isotypic with [(CH3)4N]VOF3 · H2O. Intramolecular H-bonds are found between the axial water and fluoride ligands. By additional strong intermolecular H-bonds (O ··· F 258 pm) the anions are connected to form infinite parallel chains between which the TMA cations are located. [(CH3)4N]AlF4 · H2O is shown to be isotypic.


1993 ◽  
Vol 48 (12) ◽  
pp. 1835-1836 ◽  
Author(s):  
Horst Sabrowsky ◽  
Rolf-Dieter Hitzbleck ◽  
Petra Vogt

The crystal structure of KLiTe described earlier as a dark grey powder compound has been determined by X-ray diffraction of single crystals. Very hygroscopic KLiTe crystallizes in the tetragonal space group P4/nmm (Z = 2) with the cell parameters a = 483.0(1) and c = 770.4(2) pm. The structure was determined from 211 independent reflections by Patterson and Fourier methods (R = 0.013; wR = 0.013).


1976 ◽  
Vol 31 (6) ◽  
pp. 885 ◽  
Author(s):  
H.-L. Keller.

Single crystals of TlPb2Cl5 and NH4Pb2Cl5 were prepared. X-ray diffraction data confirm the space group C2h5—P21/c (No. 14). Crystal structure determination shows a new typ, belonging to the PbCl2-structure.


2008 ◽  
Vol 63 (3) ◽  
pp. 237-243 ◽  
Author(s):  
Maria L. Fornasini ◽  
Pietro Manfrinetti ◽  
Donata Mazzone ◽  
Sudesh K. Dhar

The title compounds were synthesized and their crystal structures determined by single crystal X-ray diffraction data. Both compounds crystallize with the cubic space group Im3̄̅. Yb(Zn,Al)∽6: a = 14.299(4) Å , wR(F2) = 0.041, with Yb25.39(2)Zn138.2(3)Al7.7(3) as the refined composition; YbZn∽6: a = 14.298(4) Å , wR(F2) = 0.079, with Yb25.05(3)Zn146.83(9) as the refined composition. Their crystal structures are closely related to the YCd6 type, with two different details: Zn/Al (or Zn) atoms in the 8c sites center the cubic interstices of the structure; the pentagonal dodecahedron cavities are partially filled by ytterbium atoms in the 2a sites, with an environment topologically similar to that found in the clathrate-I compounds. Magnetic properties of the two compounds are also reported.


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