Structure and Bonding of Bromoantimonate (III) Complexes with Unusual Valency by Means of NQR and Powder X-Ray Diffraction

1994 ◽  
Vol 49 (1-2) ◽  
pp. 185-192 ◽  
Author(s):  
Tsutomu Okuda ◽  
Yoshihiro Kinoshita ◽  
Hiromitsu Terao ◽  
Koji Yamada
Keyword(s):  
Crystal Structure ◽  
Phase Transition ◽  
Bond Length ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure And Bonding ◽  
Bond Character

Abstract NQR and powder X-ray diffraction were observed for several bromoantimonate (III) complexes which contain CnH2n+1NH3 (n = 1 -3) or (CnH2n+1)2NH2(n = 1 -4) as a cation. The bond character, anion structure, crystal structure, and phase transition are discussed on the basis of the three-center-four-electron bond. A good correlation was found between the halogen NQR frequency and the Sb-X bond length.

Nitrido-und Oxochlorokomplexe des Vanadiums(V); die Kristallstruktur von AsPh4 [V0C14] Nitrido and Oxochloro Complexes of Vanadium(V); the Crystal Structure of AsPh4[VOCl4]

1980 ◽  
Vol 35 (5) ◽  
pp. 522-525 ◽  
Author(s):  
Gisela Beindorf ◽  
Joachim Strähle ◽  
Wolfgang Liebelt ◽  
Kurt Dehnicke
Keyword(s):  
Crystal Structure ◽  
Ir Spectra ◽  
Bond Length ◽  
Bond Angle ◽  
Unit Cell ◽  
X Ray Diffraction ◽  
Linear Arrangement ◽  
Space Group ◽  
X Ray ◽  
Complex Anions

The complexes AsPh4[Cl4V = N-Cl] and AsPh4[VOCl4] are prepared by the reaction of AsPh4Cl with Cl3VNCl and VOCl3, respectively. The IR spectra indicate C4v symmetry for the complex anions with multiple VN and VO bonds and a linear arrangement for the VNCl-group. AsPh4[VOCl4] crystallizes in the tetragonal space group P4/n with two formula units in the unit cell. The crystal structure was solved by X-ray diffraction methods (R = 0,062, 1096 observed, independent reflexions). The structure consists of AsPh4+ cations and [VOCl4]- anions with symmetry C4v. The extremely short VO bond length corresponds with a VO triple; its steric requirements cause the relatively large bond angle OVCl of 103.4°.

Article

1998 ◽  
Vol 76 (3) ◽  
pp. 307-312
Author(s):  
A Wallace Cordes ◽  
Robert C Haddon ◽  
Robin G Hicks ◽  
Richard T Oakley ◽  
Kristen E Vajda
Keyword(s):  
Crystal Structure ◽  
Phase Transition ◽  
Magnetic Susceptibility ◽  
Electronic Structure ◽  
Charge Transfer ◽  
Electronic Structures ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
X Ray ◽  
Diamagnetic State

Electroreduction of the 2,5-thiophene-bridged bis(1,2,3,5-diselenadiazolylium) salt [T-2,5-Se][SbF6]2 in acetonitrile, at a Pt wire and in the presence of iodine, affords a highly conductive ( sigma = 102 S cm-1 at 293 K) 1:1 charge-transfer (CT) salt [T-2,5-Se][I], the crystal structure of which has been determined by single-crystal X-ray diffraction. The crystals belong to the orthorhombic space group Fm2m, a = 3.544(2), b = 10.9808(16), c = 31.464(5) Å , V = 1224.5(7) Å 3. The structure consists of perfectly superimposed pi -stacks of molecular units bridged by columns of disordered iodines. This packing motif is similar to that of the related 1,3-benzene-bridged derivative [1,3-Se][I], but the lateral intermolecular Se···Se interactions linking adjacent pi -stacks are considerably shorter, indicative of a more isotropic electronic structure for [T-2,5-Se][I]. Magnetic susceptibility measurements on [T-2,5-Se][I] nonetheless indicate a phase transition to a diamagnetic state near 200 K, behaviour similar to that observed for [1,3-Se][I]. The electronic structures and transport properties of the two compounds are discussed in the light of extended Hückel band-structure calculations.Key words: diselenadiazolyl, diradical, charge-transfer salt, magnetic susceptibility, crystal structure.

Preparation and Structure of Bis-μ-(Benzene-1,2-Dithiolato)-bis[(benzene-1,2-dithiolato)-technetium( IV)]-Chloroform (1:1)

1988 ◽  
Vol 41 (2) ◽  
pp. 269 ◽  
Author(s):  
SF Colmanet ◽  
MF Mackay
Keyword(s):  
Crystal Structure ◽  
Bond Length ◽  
Title Compound ◽  
Binuclear Complex ◽  
Aqueous Alcohol ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Sulfur Ligand ◽  
Trigonal Prismatic

After reaction of benzene-1,2-dithiol (bdtH2) with ammonium [99Tc] pertechnetate in aqueous alcohol, extraction of the reaction mixture with chloroform yielded wine-red crystals of the title compound, C24H16S8Tc2.CHCl3. The crystal structure of the binuclear complex has been determined by X-ray diffraction. Crystals are triclinic and belong to the space group Pī with a 8.534(1), b 8.842(2), c 11.192(3)Ǻ, α 107.02(2), β 98.13(1), γ 100.60(2)° with Z 1. Refinement on 1524 data measured with Cu Kα radiation converged at R 0.082. The complex has exact Ci point symmetry and pseudo-C2 symmetry. Each technetium atom is coordinated to a trigonal -prismatic array of six sulfur ligand atoms. These arrays are fused through a quadrilateral face defined by the four bridging sulfur atoms of two benzene-1,2- dithiolato ligands to give a Tc2S8 core of D2h pseudo-symmetry. As a Tc - Tc bond [bond length 2.591(3)Ǻ] passes through the mid point of the quadrilateral face, this novel geometry can be described in terms of capped trigonal prisms. The chloroform is disordered.

scholarly journals Crystal structure of the high-P polymorph of Ca2B6O6(OH)10·2(H2O) (meyerhofferite)

2021 ◽  
Vol 77 (6) ◽  
Author(s):  
Davide Comboni ◽  
Tomasz Poreba ◽  
Francesco Pagliaro ◽  
Tommaso Battiston ◽  
Paolo Lotti ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Phase Transition ◽  
High Pressure ◽  
Large Volume ◽  
Atomic Scale ◽  
Deformation Mechanisms ◽  
X Ray Diffraction ◽  
X Ray ◽  
First Order ◽  
Structural Differences

The crystal structure of the high-pressure polymorph of meyerhofferite, ideally Ca2B6O6(OH)10·2(H2O), has been determined by means of single-crystal synchrotron X-ray diffraction data. Meyerhofferite undergoes a first-order isosymmetric phase transition to meyerhofferite-II, bracketed between 3.15 and 3.75 GPa, with a large volume discontinuity. The phase transition is marked by an increase in the coordination number of the boron B1 site, from III to IV, leading to a more interconnected and less compressible structure. The main structural differences between the two polymorphs and the P-induced deformation mechanisms at the atomic scale are discussed.

Crystal structure and the equation of state of thorium monophosphide for pressures up to 50 GPa

1989 ◽  
Vol 22 (1) ◽  
pp. 61-63 ◽  
Author(s):  
J. S. Olsen ◽  
L. Gerward ◽  
U. Benedict ◽  
H. Luo ◽  
O. Vogt
Keyword(s):  
Crystal Structure ◽  
Phase Transition ◽  
High Pressure ◽  
Synchrotron Radiation ◽  
Diamond Anvil Cell ◽  
X Ray Diffraction ◽  
Pressure Derivative ◽  
X Ray ◽  
Cscl Structure ◽  
Diamond Anvil

High-pressure X-ray diffraction studies have been performed on ThP using synchrotron radiation and a diamond-anvil cell. The bulk modulus B 0 and its pressure derivative B′0 have been determined (B 0 = 137 GPa; B′0 = 5.1). A phase transition from the NaCl structure to the CsCl structure was observed at about 30 GPa.

scholarly journals Structural Study of Ferroelectric Phase Transition of Sn-doped SrTiO3

2014 ◽  
Vol 70 (a1) ◽  
pp. C61-C61 ◽  
Author(s):  
Hirofumi Kasatani ◽  
Shoichiro Suzuki ◽  
Akira Ando ◽  
Eisuke Magome ◽  
Chikako Moriyoshi ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Phase Transition ◽  
Local Structure ◽  
Ferroelectric Phase Transition ◽  
Nearest Neighbor ◽  
Ferroelectric Phase ◽  
Rietveld Analysis ◽  
Temperature Phase ◽  
X Ray Diffraction ◽  
X Ray

Recently, ferroelectricity was discovered in Sn-doped SrTiO3 (abbreviated by SSTO), in which Sr-atom was substituted by a few percent Sn-atom[1]. The ferroelctricity of SSTO was confirmed by means of the appearance of the dielectric anomaly, that reached several thousands and the clear D-E hysteresis loop in low temperature phase. In order to clarify the mechanism of ferroelectric phase transition of SSTO from the viewpoint of the crystal structure, we investigated the average crystal structure and the local structure around the substitutional Sn-atom of SSTO10 (10% Sn concentration, ferroelectric phase transition temperature 180K) by means of synchrotron-radiation powder X-ray diffraction and transmission XAFS spectrum of Sn:K-edge, respectively. From the results of MEM/Rietveld analysis of powder X-ray diffraction data, it was obtained that crystal structure of paraelectric phase of SSTO10 was cubic perovskite structure with the disorder state of Sn-atom. In ferroelectric phase, the crystal system was tetragonal, which was similar in structure to tetragonal ferroelectric structure of BaTiO3, and Sn-atom was order state. XAFS study revealed that the valence of Sn-ion was +2 charge and the local structure of Sn-atom was seemed as being the self-insistent state of SnO crystal structure. However, strangely, the coordination number of the nearest neighbor atom, that is O-atom, was 2 instead of 4. This is a mystery result and we have been analyzing. We have considered that the ferroelectricity of SSTO is induced by the distortion around the subsitituional Sn-atom. At the meeting, we are planning to discuss the precise crystal structure and the mechanism of the ferroelectric phase transition of SSTO.

Consolidation of Mg2Si Powder Using Shockwave Generated by Projectile Impact

2013 ◽  
Vol 767 ◽  
pp. 177-182 ◽  
Author(s):  
Hiroaki Kishimura ◽  
Yuki Yano ◽  
Hitoshi Matsumoto
Keyword(s):  
Crystal Structure ◽  
Phase Transition ◽  
Milled Powder ◽  
Shock Pressure ◽  
Original Structure ◽  
Ambient Conditions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Shock Compaction ◽  
Phase Transition Pressure

A series of shock compaction experiments on as-received and ball-milled Mg2Si powder were conducted. The crystalline size in the shocked compacts obtained from the ball-milled powder was equivalent to that of the compacts obtained from the as-received powder. Although the shock pressure was higher than the phase transition pressure, the crystal structure reverted to its original structure under ambient conditions. For the shocked compact obtained from the ball-milled powder, a MgO peak appeared in the X-ray diffraction pattern.

scholarly journals Crystal structure of 16-ferrocenylmethyl-3β-hydroxyestra-1,3,5(10)-trien-17-one: a potential chemotherapeutic drug

2016 ◽  
Vol 72 (6) ◽  
pp. 868-871 ◽  
Author(s):  
José A. Carmona-Negrón ◽  
Mariola M. Flores-Rivera ◽  
Zaibeth Díaz-Reyes ◽  
Curtis E. Moore ◽  
Arnold L. Rheigold ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Double Bond ◽  
Bond Length ◽  
Dimethyl Sulfoxide ◽  
Torsion Angle ◽  
Chemotherapeutic Drug ◽  
X Ray Diffraction ◽  
X Ray ◽  
Carbonyl Bond

A new ferrocene complex, 16-ferrocenylmethyl-3β-hydroxyestra-1,3,5(10)-trien-17-one dimethyl sulfoxide monosolvate, [Fe(C5H5)(C24H27O2)]·C2H6OS, has been synthesized and structurally characterized by single-crystal X-ray diffraction techniques. The molecule crystallizes in the space groupP21with one molecule of dimethyl sulfoxide. A hydrogen bond links the phenol group and the dimethyl sulfoxide O atom, with an O...O distance of 2.655 (5) Å. The ferrocene group is positioned in the β face of the estrone moiety, with an O—C—C—C torsion angle of 44.1 (5)°, and the carbonyl bond length of the hormone moiety is 1.216 (5) Å, typical of a C=O double bond. The average Fe—C bond length of the substituted Cp ring [Fe—C(Cp*)] is similar to that of the unsubstituted one [Fe—C(Cp)],i.e.2.048 (3)versus2.040 (12) Å. The structure of the complex is compared with those of estrone and ethoxymethylestrone.

scholarly journals Phase Transition and Crystal Structure of the Si(111)-.RAD.3*.RAD.3-Ag Surface Studied by X-ray Diffraction

Hyomen Kagaku ◽  
2005 ◽  
Vol 26 (6) ◽  
pp. 322-328
Author(s):  
Hiroo TAJIRI ◽  
Kazushi SUMITANI ◽  
Toshio TAKAHASHI
Keyword(s):  
Crystal Structure ◽  
Phase Transition ◽  
X Ray Diffraction ◽  
X Ray
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