Crystal structure, powder X-Ray diffraction, Hirshfeld, thermal, Infrared-Raman studies, and symmetry analysis of the relationship between the novel tetragonal [(CH3)4N]2SiF6 and the cubic Fm3m antifluorite structure

2021 ◽  
pp. 131455
Author(s):  
A. Ouasri ◽  
A. Rhandour ◽  
M. Saadi ◽  
L. El Ammari
Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 4067
Author(s):  
Giovanni Ricci ◽  
Giuseppe Leone ◽  
Giorgia Zanchin ◽  
Benedetta Palucci ◽  
Alessandra Forni ◽  
...  

Some novel cobalt diphenylphosphine complexes were synthesized by reacting cobalt(II) chloride with (2-methoxyethyl)diphenylphosphine, (2-methoxyphenyl)diphenylphosphine, and 2-(1,1-dimethylpropyl)-6-(diphenylphosphino)pyridine. Single crystals suitable for X-ray diffraction studies were obtained for the first two complexes, and their crystal structure was determined. The novel compounds were then used in association with methylaluminoxane (MAO) for the polymerization of 1,3-butadiene, and their behavior was compared with that exhibited in the polymerization of the same monomer by the systems CoCl2(PnPrPh2)2/MAO and CoCl2(PPh3)2/MAO. Some significant differences were observed depending on the MAO/Co ratio used, and a plausible interpretation for such a different behavior is proposed.


2018 ◽  
Vol 74 (8) ◽  
pp. 936-943
Author(s):  
Galina V. Kiriukhina ◽  
Olga V. Yakubovich ◽  
Ekaterina M. Kochetkova ◽  
Olga V. Dimitrova ◽  
Anatoliy S. Volkov

Caesium manganese hexahydrate phosphate, CsMn(H2O)6(PO4), was synthesized under hydrothermal conditions. Its crystal structure was determined from single-crystal X-ray diffraction data. The novel phase crystallizes in the hexagonal space group P63 mc and represents the first manganese member in the struvite morphotropic series, AM(H2O)6(TO4). Its crystal structure is built from Mn(H2O)6 octahedra and PO4 tetrahedra linked into a framework via hydrogen bonding. The large Cs atoms are encapsulated in the framework cuboctahedral cavities. It is shown that the size of the A + ionic radius within the morphotropic series AM(H2O)6(XO4) results is certain types of crystal structures and affects the values of the unit-cell parameters. Structural relationships with Na(H2O)Mg(H2O)6(PO4) and the mineral hazenite, KNa(H2O)2Mg2(H2O)12(PO4)2, are discussed.


2019 ◽  
Vol 75 (5) ◽  
pp. 504-507 ◽  
Author(s):  
Hui-Ru Chen

Excellent fluorescence properties are exhibited by d 10 metal compounds. The novel three-dimensional ZnII coordination framework, poly[[{μ2-bis[4-(2-methyl-1H-imidazol-1-yl)phenyl] ether-κ2 N 3:N 3′}(μ2-furan-2,5-dicarboxylato-κ2 O 2:O 5)zinc(II)] 1.76-hydrate], {[Zn(C6H2O5)(C20H18N4O)]·1.76H2O} n , has been prepared and characterized using IR spectroscopy, elemental analysis and single-crystal X-ray diffraction. The crystal structure analysis revealed that the compound exhibits a novel fourfold interpenetrating diamond-like network. This polymer also displays a strong fluorescence emission in the solid state at room temperature.


1992 ◽  
Vol 47 (8) ◽  
pp. 1075-1078 ◽  
Author(s):  
Karin Ruhlandt-Senge ◽  
Ulrich Müller

When hexymethylbenzene-cyclopentadienyl-iron reacts with ozone in dichloromethane, the title compound is one of the products. Its crystal structure was determined by X-ray diffraction (R = 0.145 for 1412 unique reflexions). Crystal data: a = 1815.1(8), b = 1314.8(5), c = 1823.0(8) pm, space group Pbca, Z = 8. The sandwich-like [η6-C6Me6Fe-η5-C5H5]+ ions exhibit large thermal motions, and the CH2C12 molecules are disordered in two orientations. The novel [Fe2Cl6]2- ion has the structure of two tetrahedra sharing an edge. Its IR spectrum is reported.


2021 ◽  
Vol 26 (1(77)) ◽  
pp. 16-25
Author(s):  
Yu. I. Slyvka ◽  
E. A. Goreshnik ◽  
N. T. Pokhodylo ◽  
М. G. Mys’kiv

This work is focused on the synthesis and structure characterization of the novel Cu(I) π-complex [Cu2(Thiaz1)2(ClO4)2] (1) with 2-allylamino-5-methyl-1,3,4-thiadiazole (Thiaz1) ligand. The crystals of the compound were obtained by means of the alternating-current electrochemical technique and studied using single crystal X-ray diffraction. The crystal structure of the complex 1 is constructed from the centrosymmetric dimers, in which two copper(I) ions are coordinated by two Thiaz1 molecules through thiadiazole N atoms and allylic C=C bond. Energy framework computational analysis for structure 1 has been performed.  


2008 ◽  
Vol 41 (3) ◽  
pp. 584-591 ◽  
Author(s):  
Jiandong Fan ◽  
Huaijin Zhang ◽  
Wentao Yu ◽  
Haohai Yu ◽  
Jiyang Wang ◽  
...  

A transparent Yb3+:NaY(WO4)2single crystal with dimensions of 30 mm (diameter) × 40 mm has been grown by the Czochralski method. The high crystalline quality of the as-grown Yb3+:NaY(WO4)2crystals was confirmed by high-resolution X-ray diffraction. The effective segregation coefficients of elemental Yb, Na, Y and W in Yb3+:NaY(WO4)2were measured using the X-ray fluorescence method. Powder and single-crystal X-ray diffraction data of NaYb0.05Y0.95(WO4)2are reported. The structure refinement shows that NaYb0.05Y0.95(WO4)2crystallizes in the tetragonal space groupI41/a, witha=b= 5.2039 (2),c= 11.2838 (9) Å, α = β = γ = 90°,V= 305.57 (3) Å3andZ= 2. A series of possible growth faces (hkl) were determined from the crystal lattice and symmetry according to the Bravais–Friedel Donnay–Harker theory, and the relationship among crystal structure, growth habits and crystal morphology is discussed. In addition, the thermal properties of the crystal, including the specific heat, thermal expansion, thermal diffusion and thermal conductivity, were carefully investigated. The anisotropy of the crystal thermal conductivities is explained from the point of view of the crystal structure.


1987 ◽  
Vol 40 (7) ◽  
pp. 1169 ◽  
Author(s):  
JA Elix ◽  
KL Gaul ◽  
M Sterns ◽  
MW Binsamsudin

The structure determination of thiomelin (2,4-dichloro-1,8-dihydroxy-5-methoxy-6-methyl-9H-xanthen-9-one) (3), an unusual lichen metabolite probably derived biosynthetically by oxidative ring opening of a precursor anthraquinone, is reported. The crystal structure of thiomelin diacetate (4) was determined by X-ray diffraction, while that of the cogenors 8-O-methylthiomelin (5), 4-dechlorothiomelin (7), 4-dechloro-8- O- methylthiomelin (9), 2-dechloro-8- O- methylthiomelin (10) and 2,4-dichloro-l-hydroxy-7-methoxy-6,8-dimethyl-9H-xanthen-9-one (12) were deduced from spectroscopic data.


2007 ◽  
Vol 350 ◽  
pp. 209-212 ◽  
Author(s):  
Hiroshi Yoshida ◽  
Masayuki Takada ◽  
Shinzo Yoshikado

The relationship between the crystal structure of Bi2O3 and the recovery of the electrical degradation of ZnO varistors was investigated. The evaluation methods used were analysis of the voltage-current (V-I) characteristics, scanning electron microscopy (SEM), energy-dispersion X-ray spectroscopy (EDX), and X-ray diffraction (XRD) measurements. The electrical degradation was estimated by the nonlinearity of the V-I characteristics. A marked recovery of the nonlinearity of the V-I characteristics was observed for a sample having the crystal structure of δ-type Bi2O3. It is speculated that the electrical degradation is markedly recovered for optimum conditions of both the amount and the crystal structure of the added Bi2O3, because, for samples sintered for a long time, the recovery speed is shorter than that for samples sintered for a shorter time. During long-time sintering, the amount of Bi2O3 decreased because of evaporation. No change of the crystal structure of Bi2O3 was observed upon repeated the electrical degradation and the recovery. It is suggested that another mechanism apart from the diffusion of oxygen ions through the grain boundaries of ZnO particles contributes to the electrical degradation and recovery of the nonlinearity of V-I characteristics.


1992 ◽  
Vol 247 ◽  
Author(s):  
Jun Tsukamoto ◽  
Akio Takahashi

ABSTRACTWe have carried out structural analyses of highly conductive polyacetylene in order to elucidate the relationship between stucture and electrical properties. Sharp X-ray diffraction lines were observed for the heavily iodine-doped polyacetylene showing high conductivity, in contrast with the diffused diffractions of the conventional one. SEM observation reveals that granular structure of the new polyacetylene is composed of densely packed micro-fibrils. The result from the resonance Raman analysis indicates that the new cis-polyacetylene contains more longer conjugated segments than conventional polyacetylene. The relationship between the structure and conductivity is discussed, basing on the crystal structure and morphology observed.


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