Synthèse et caractérisation des oxypentafluorouranates(VI) NH4UOF5, KUOF5, RbUOF5 et CsUOF5

1978 ◽  
Vol 56 (14) ◽  
pp. 1874-1880 ◽  
Author(s):  
Philippe Joubert ◽  
Roland Bougon ◽  
Bernard Gaudreau
Keyword(s):  
Infrared Spectroscopy ◽  
Solid State ◽  
Alkali Metal ◽  
Vibrational Spectroscopy ◽  
Uranium Atom ◽  
The Other ◽  
Metal Fluoride ◽  
X Ray Diffraction ◽  
X Ray ◽  
Raman And Infrared Spectroscopy

The oxypentafluorouranates(VI) MUOF5, where M = NH4, K, Rb, Cs, have been synthetized from reaction of UOF4 with the ammonium or corresponding alkali metal fluoride in liquid SO2. According to X-ray diffraction, Raman and infrared spectroscopy, and from an isomorphism with the corresponding hexafluorouranates(V) MUF6, two different environments around the uranium atom are observed. In CsUOF5 the five fluorine atoms and the oxygen around the uranium result in a pseudo-octahedral surrounding whereas for the other complexes (M = NH4, K, Rb) each uranium is surrounded by eight light atoms forming a dodecahedron. In this structure the dodecahedra are linked together by fluorine atoms to form infinite chains. The UOF5− ion has been characterized by vibrational spectroscopy in the solid state. The proposed assignment, which was made with the assumption of a C4v symmetry of the UOF5− ion, was confirmed by a force constant calculation. From these data and contrary to the values reported for comparable oxypentafluoroanions, the axial fluorine is found to be less ionic than the equatorial ones.

Influence of Molecular Conformation on the Solid State Packing of 1,2-Diglycerides Study of 1,2-Dipalmitin and Some Structural Analogs by Electron Diffraction, X-Ray Diffraction, and Infrared Spectroscopy

1978 ◽  
Vol 33 (1-2) ◽  
pp. 39-49 ◽  
Author(s):  
Douglas L. Dorset ◽  
Walter A. Pangborn ◽  
Anthony J. Hancock ◽  
Iris S. Lee
Keyword(s):  
Infrared Spectroscopy ◽  
Solid State ◽  
Room Temperature ◽  
Molecular Conformation ◽  
Crystalline Solid ◽  
X Ray Diffraction ◽  
Chain Packing ◽  
X Ray ◽  
Monoclinic Form ◽  
Extended Chain

Abstract Diffraction studies on natural 1,2-dipalmitin and on analogs, including those based on the configurational isomers of cyclopentane-1,2,3-triol reveal that the 1,2-diglycerides crystallize from solvent with chain methylene packing identical to the monoclinic form of even-chain alkanes. The chains probably are folded back in “hairpin” fashion as found in phospholipid crystal structures. Acyl shifts are observed to occur in the crystalline solid state at room temperature to give the 1,3-diglyceride. Analogs based on the above-mentioned cyclitols show that isomers with adjacent chains trans to the ring (possibly extended chain packing) or with chains cis to the ring (“hair­ pin”) crystallize readily. Both possibly extended chain configurational isomers have the α-form as well as β′-forms and a β-polymorph. The hairpin isomers each give a β′-polymorph but only the all-cts isomer gives an α-form.

Powder X-Ray Data for Synthetic Anhydrous Sodium Zirconium Silicates

1987 ◽  
Vol 2 (3) ◽  
pp. 176-179 ◽  
Author(s):  
G. Wilson ◽  
F. P. Glasser
Keyword(s):  
Solid State ◽  
Diffraction Pattern ◽  
Powder Diffraction ◽  
Solid State Reaction ◽  
The Other ◽  
X Ray Diffraction ◽  
Powder Diffraction File ◽  
X Ray ◽  
Sodium Zirconium ◽  
Diffraction Patterns

AbstractA systematic survey of phase formation in the Na2O-ZrO2-SiO2 system has revealed inconsistencies in the number and identity of ternary phases, and of their X-ray powder data. The phases Na2ZrSiO5, Na4Zr2Si3O12, Na2ZrSi2O7 and Na2ZrSi4O11 were prepared by solid-state reaction and their experimental X-ray diffraction patterns measured. Calculated X-ray diffraction patterns were generated by computer, using published crystallographic data, and critically compared with the experimentally observed values. The unit-cell constants were redefined to a greater accuracy than the presently accepted values published in the Powder Diffraction File. Only Na4Zr2Si3O12 produced an X-ray diffraction pattern which agreed with that previously published; those from the other phases were significantly different in both the intensities and positions of the reflections. Data for synthetic Na2ZrSi4O11 identical to the mineral vlasovite are reported.

Interactions de l'ion Ag+ avec la glutarimide

1984 ◽  
Vol 62 (7) ◽  
pp. 1287-1291 ◽  
Author(s):  
Johanne Perron ◽  
André L. Beauchamp
Keyword(s):  
Infrared Spectroscopy ◽  
Infrared Spectrum ◽  
Nmr Spectra ◽  
The Other ◽  
Mirror Plane ◽  
Bond Orders ◽  
X Ray Diffraction ◽  
Complex Species ◽  
X Ray ◽  
C Nmr

The 1:1 complex formed between Ag+ ions and glutarimide was investigated by X-ray diffraction, infrared spectroscopy, and 1H and 13C nmr. The crystals are monoclinic, C2/c, a = 13.497(3) Å, b = 9.503(2) Å, c = 9.600(4) Å, β = 92.30(3)°, Z = 4 molecules per cell. The structure was refined on 1086 nonzero [Formula: see text] reflections to R = 0.027. One half of the Ag atoms are linearly coordinated to the N atoms of two deprotonated glutarimide ligands, whereas the other half are surrounded by an approximate tetrahedron of four carbonyl oxygens belonging to two adjacent [Glu–Ag–Glu]− units. The [Glu–Ag–Glu]− groups are joined by tetrahedrally coordinated Ag atoms into infinite chains along the c axis. Complexation introduces a number of changes in the infrared spectrum of glutarimide. They can be related to the disappearance of the N—H vibrator and the change of bond orders in the —C(O)—N—C(O)— portion of the ligand. The nmr spectra show that coordinated glutarimide retains a mirror plane when the Ag complex is dissolved in DMSO. This suggests that the O-bonded Ag atoms dissociate to a large extent in solution, leaving the linear [Glu–Ag–Glu]− ions as the major glutarimide complex species.

Syntheses and crystal structures of trigonal rare-earth dioxymonocyanamides, Ln2O2CN2 (Ln=Dy, Ho, Er, Tm, Yb)

2007 ◽  
Vol 22 (1) ◽  
pp. 59-63 ◽  
Author(s):  
Min Li ◽  
Wenxia Yuan ◽  
Jingfang Wang ◽  
Cong Gu ◽  
Huaizhou Zhao
Keyword(s):  
Rare Earth ◽  
Infrared Spectroscopy ◽  
Solid State ◽  
Rietveld Method ◽  
Reaction Pathways ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cell Parameters ◽  
Trigonal System ◽  
Xrd Patterns

Trigonal rare-earth dioxymonocyanamides Ln2O2CN2 (Ln=Dy, Ho, Er, Tm, Yb) were synthesized by the modified solid-state metathesis (SSM) method, in which Ln2O3 and melamine C3N6H6 were mixed and heated at 850 °C in vacuumed silica ampoules. Possible chemical reaction pathways are proposed. X-ray diffraction (XRD) patterns of Ln2O2CN2 were refined using the Rietveld method. Compounds Ln2O2CN2 crystallize in the trigonal system with space group P3m1, Z=1, and cell parameters of a and c varying from 3.7267(1) to 3.6407(1) Å and from 8.1848(3) to 8.1152(3) Å, respectively, as Ln atoms change from Dy to Yb. These compounds have stacking structures of Ln2O22+ and CN22− layers, similar to those of previously reported compounds Ln2O2CN2 (Ln=Ce, Pr, Nd, Sm, Eu, Gd). The presence of CN22− ions has been confirmed by infrared spectroscopy, with two characteristic peaks in the vicinity of 651 and 2075 cm−1.

scholarly journals Reduced roughness for improved mobility in benzodipyrrolidone-based, n-type OFETS

2014 ◽  
Vol 2 (41) ◽  
pp. 8822-8828 ◽  
Author(s):  
J. W. Rumer ◽  
S. Rossbauer ◽  
M. Planells ◽  
S. E. Watkins ◽  
T. D. Anthopoulos ◽  
...  
Keyword(s):  
Solid State ◽  
Electron Mobility ◽  
Film Surface ◽  
The Other ◽  
Surface Topology ◽  
X Ray Diffraction ◽  
X Ray ◽  
Bottom Contact ◽  
Out Of Plane

Six phenyl-flanked benzodipyrrolidone-based copolymers are designed, synthesised and characterised. Three exhibit backbone in-plane curvature or out-of-plane twisting, while the other three remain planar and co-linear. While the first three appear less crystalline by X-ray diffraction, they afford a smoother solid-state film surface topology and increased electron mobility in top-gate, bottom-contact OFETs.

High Pressure Study of Ru3(CO)12by X-ray Diffraction, Raman, and Infrared Spectroscopy

2004 ◽  
Vol 43 (17) ◽  
pp. 5245-5252 ◽  
Author(s):  
Carla Slebodnick ◽  
Jing Zhao ◽  
Ross Angel ◽  
Brian E. Hanson ◽  
Yang Song ◽  
...  
Keyword(s):  
High Pressure ◽  
Infrared Spectroscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Raman And Infrared Spectroscopy ◽  
High Pressure Study

Synthesis, Characterization, Crystal Structure and hybrid DFT Computation of the Chlorooxoarsenate(III), [NMe4]2[As4O2Cl10]·2 CH3CN

2001 ◽  
Vol 56 (3) ◽  
pp. 301-305 ◽  
Author(s):  
Thomas M. Klapötke ◽  
Thomas Schütt
Keyword(s):  
Crystal Structure ◽  
Infrared Spectroscopy ◽  
Normal Modes ◽  
Nbo Analysis ◽  
Crystallographic Data ◽  
Computational Results ◽  
X Ray Diffraction ◽  
Aerobic Conditions ◽  
X Ray ◽  
Raman And Infrared Spectroscopy

Abstract [NMe4]2 [As4O2Cl10] · 2 CH3CN was recovered by the reaction of [NMe4][N3] with AsCl3 in CH3CN under aerobic conditions. This compound was also obtained directly by the reaction of AsCl3, AS2O3 and [NMe4][Cl] in acetonitrile. The structure was determined by X-ray diffraction. [NMe4]2 [As4O2Cl10] · 2 CH3CN crystallizes in theoorthorhombic space group Fmmm with a = 11.4144(8), b = 14.732(1) and c = 19.803(2) Å, with 4 formula units per unit cell. The frequencies obtained by Raman and infrared spectroscopy were assigned to the normal modes of the [As4O2Cl10]2- anion in comparison with computational results. The bonding situation in the [As4O2Cl10]2- anion was elucidated on the basis of an NBO analysis on the crystallographic data.

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