scholarly journals THE RESEARCH OF THE THERMOLYSIS PRODUCTS OF CESIUM TUNGSTOPHOSPHATES

2021 ◽  
Vol 5 (12) ◽  
pp. 126-135
Author(s):  
Y. Moroz ◽  
M. Lozynskyy ◽  
A. Lopanov ◽  
K. Chebyshev ◽  
V. Burkhovetsky
Keyword(s):  
Thermal Decomposition ◽  
Heterogeneous Catalysts ◽  
Materials Science ◽  
Copper Ions ◽  
Tungsten Bronze ◽  
Pyrochlore Structure ◽  
Research Results ◽  
Cell Parameters ◽  
Oxidation Of Organic Compounds ◽  
New Compounds

The article deals with the synthesis, study of thermal decomposition and identification of the thermolysis products of cesium tungstophosphates that are promising compounds in the field of materials science, catalysis and other fields of science and technology. Compounds with the Keggin anion structure are synthesized from aqueous solutions: Cs3[PW12O40] ∙ 9H2O; Cs5Na2[PW11O39(H2O)] ∙ 5H2O and Cs5[PW11O39Ni0,5Cu0,5(H2O)] ∙ 4H2O. The processes of their thermal decomposition are investigated and some regularities of their thermolysis are established. Thermolysis products are identified: Cs3PW12O40, phases with the structure of pyrochlore and hexagonal tungsten bronze of the composition Cs10/13Na4/13P2/13W22/13O6 and Cs10/13P2/13Ni1/13Cu1/13W22/13O6. The unit cell parameters of the phase with the pyrochlore structure are determined. Research results confirm that phosphorus, nickel and copper ions are included in the structure of pyrochlore and hexagonal tungsten bronze. Phases similar to this chemical composition are not previously known in the literature. The studied tungstophosphates and their thermolysis products are promising compounds for obtaining heterogeneous catalysts for the oxidation of organic compounds and selective sorbents. The research results can be useful for predicting the thermal properties and phase composition of thermolysis products of similar polyoxometallates in order to obtain new compounds with the structure of pyrochlore and hexagonal tungsten bronze, as well as composite materials based on them.

Two lithium tricyanomethanide compounds: syntheses and single-crystal structure determination of LiK[C(CN)3]2 and Li[C(CN)3]·½ (H3C)2CO

2015 ◽  
Vol 70 (3) ◽  
pp. 191-196 ◽  
Author(s):  
Olaf Reckeweg ◽  
Francis J. DiSalvo
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Single Crystals ◽  
Structure Determination ◽  
Monoclinic Space Group ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
Cell Parameters ◽  
New Compounds

AbstractThe new compounds LiK[C(CN)3]2 and Li[C(CN)3]·½ (H3C)2CO were synthesized and their crystal structures were determined. Li[C(CN)3]·½ (H3C)2CO crystallizes in the orthorhombic space group Ima2 (no. 46) with the cell parameters a=794.97(14), b=1165.1(2) and c=1485.4(3) pm, while LiK[C(CN)3]2 adopts the monoclinic space group P21/c (no. 14) with the cell parameters a=1265.7(2), b=1068.0(2) and c=778.36(12) pm and the angle β=95.775(7)°. Single crystals of K[C(CN)3] were also acquired, and the crystal structure was refined more precisely than before corroborating earlier results.

TUNGSTEN OXIDES AND BRONZES: SYNTHESIS, DIFFUSION AND REACTIVITY

1993 ◽  
Vol 07 (23n24) ◽  
pp. 4145-4164 ◽  
Author(s):  
JING-DONG GUO ◽  
M. STANLEY WHITTINGHAM
Keyword(s):  
Tungsten Bronze ◽  
Pyrochlore Phase ◽  
Reaction Medium ◽  
Pyrochlore Structure ◽  
Ionic Mobility ◽  
Soft Chemistry ◽  
Quarter Century ◽  
Tungsten Oxides ◽  
Hydronium Ion ◽  
Wide Range

The tungsten oxides and bronzes have been extensively studied since their discovery in the last century, because of their brilliant colors and high electrical conductivity. More recently the driving interest resulted from their potential use in electrochromic displays and other electrochemical systems. Their crystalline structures are generally based on the corner sharing of WO 6 octahedra giving tunnels of variable size and shape leading to exciting intercalation chemistry. These structures readily undergo redox reactions, and in the last quarter century these reactions have often involved soft chemistry. Most recently hydrothermal techniques have been used to prepare new sodium tungstates with the hexagonal tungsten bronze and the pyrochlore structures. The phase formed is a function of the pH of the reaction medium. The pyrochlore phase readily undergoes ion-exchange with a wide range of monovalent cations giving the compounds, M x W 2 O 6+x/2 · y H 2 O ; the value of y is strongly dependent on the identity of the cation, M. WO 3 with the pyrochlore structure could be formed from the hydronium and ammonium complexes. Lithium can be readily intercalated either chemically and electrochemically into both these phases, just as in the previously-known bronze phases. Surprisingly more lithium is incorporated in most cases in the hexagonal than in the pyrochlore phase. The ions in the pyrochlore structure show rapid ionic mobility, with the hydronium ion showing the greatest mobility.

Reactions of t-Butyl Peresters, XVI Reactions of Diakyl t-Butylperoxy Phosphates and Alkyl t-Butylperoxy Alkylphosphonates with Cycloalkenes in the Presence of Copper Ions

1978 ◽  
Vol 33 (10) ◽  
pp. 1165-1176 ◽  
Author(s):  
George Sosnovsky ◽  
Gary Karas
Keyword(s):  
Thermal Decomposition ◽  
Thermal Instability ◽  
Copper Ions ◽  
Copper Ion ◽  
Analogous Reaction ◽  
Imidazole Derivatives

Abstract The reactions of dialkyl t-butylperoxy phosphates (1) and alkyl t-butylperoxy alkylphosphonates (2) with cyclohexene in the presence of a catalyticamount of copper (I) bromide at 80 °C in benzene afforded the corresponding phosphates (3) and phosphonates (4) in 50 to 70% yield. The analogous reaction of 1 (R = i-C3H7) with cycloheptene also gave the corresponding phosphate (8, n = 3)in 71% yield. However, phosphorylated cyclopentene (8, n = 1) and cyclooctene (8, n - 4) derivatives could not be isolated because of their thermal instability, and only the corresponding 1,3-cyclopentadiene and 1,3-cyclooctadiene were obtained in 92 and 38% yields, respectively. Thermal decomposition of 3 and 4 in the absence of a solvent at 110-115 °C gave 1,3-cyclohexadiene in 70 to 90% yield. For identification purposes, compounds 3 and 4 were prepared from the corresponding imidazole derivatives 5 and 6 and 2-cyelohexen- l-ol (7).A mechanism is proposed for the copper ion catalyzed reaction of 1 and 2 with cycloalkenes.

Electrical Conduction of New Compounds (Ca, Ce)2Sn2O7 and (Sr, Ce)2Sn2O7 with Pyrochlore Structure

1993 ◽  
Vol 102 (2) ◽  
pp. 349-353 ◽  
Author(s):  
Naoki Wakiya ◽  
Shin Nishiyama ◽  
Kazuo Shinozaki ◽  
Nobuyasu Mizutani
Keyword(s):  
Electrical Conduction ◽  
Pyrochlore Structure ◽  
New Compounds

From Coordination Complexes to Potential Heterogeneous Catalysts via Solid‐State Thermal Decomposition: Precursor, Atmosphere and Temperature as Tuning Variables

2019 ◽  
Vol 4 (28) ◽  
pp. 8365-8371
Author(s):  
José Pérez ◽  
José L. Serrano ◽  
Gregorio Sánchez ◽  
Pedro Lozano ◽  
Ivan da Silva ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Solid State ◽  
Heterogeneous Catalysts ◽  
Coordination Complexes

scholarly journals New Poly(Propylene Imine) Dendrimer Modified with Acridine and Its Cu(II) Complex: Synthesis, Characterization and Antimicrobial Activity

Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 3020 ◽  
Author(s):  
Paula Bosch ◽  
Desislava Staneva ◽  
Evgenia Vasileva-Tonkova ◽  
Petar Grozdanov ◽  
Ivanka Nikolova ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Copper Ions ◽  
Spectral Characteristics ◽  
Dilution Method ◽  
Pathogenic Microorganisms ◽  
Paramagnetic Resonance ◽  
Poly Propylene ◽  
New Compounds ◽  
First Time

A second-generation poly(propylene imine) dendrimer modified with acridine and its Cu(II) complex have been synthesized for the first time. It has been found that two copper ions form complexes with the nitrogen atoms of the dendrimeric core by coordinate bonds. The new compounds have been characterized by nuclear magnetic resonance (NMR), electron paramagnetic resonance (EPR), fourier-transform infrared spectroscopy (FTIR) and fluorescence spectroscopy. The spectral characteristics of the modified dendrimer have been measured in different organic solvents, and a negative fluorescence solvatochromism has been observed. The antimicrobial activity of the dendrimers has been tested against model pathogenic microorganisms in agar and by broth dilution method. The cotton fabric treated with both dendrimers has been evaluated towards pathogenic microorganisms. The obtained modified cotton fabrics have been shown to hamper bacterial growth and to prevent biofilm formation. Dendrimer cytotoxicity has been investigated in vitro in the model HEp-2 cell line.

scholarly journals Study of Tantalum Substituted Potassium Tungsten Bronzes

2012 ◽  
Vol 25 (1) ◽  
pp. 38-45 ◽  
Author(s):  
Md Mahbubur R Shakil ◽  
Tapas Debnath ◽  
Claus H Ruscher ◽  
Altaf Hussain
Keyword(s):  
Cell Parameter ◽  
Tungsten Bronze ◽  
Chemical Society ◽  
Metallic Phase ◽  
Solid State Method ◽  
X Ray ◽  
Cell Parameters ◽  
Conventional Solid State Method ◽  
Infrared Absorption Spectra ◽  
Two Phases

A series of compounds KxTayW1-yO3 with x = 0.30, 0.00 ? y ? 0.30 and x = 0.55, 0.00 ? y ? 0.10 were synthesized by conventional solid-state method. The samples were characterized using XRD and FTIR spectroscopy. X-ray powder patterns reveal that the samples with compositions x = 0.30, y ? 0.30 show hexagonal tungsten bronze (HTB) type phase and the samples with x = 0.55, 0.02 ? y ? 0.10 show a mixture of two phases (K-HTB and tetragonal potassium tungsten bronze, K-TTB). The samples of the system, K0.30TayW1-yO3 with 0.00 ? y ? 0.15 shows no significant change in the cell parameters. However, for the composition y > 0.15, the cell parameter a decreases and c increases with increasing Ta content, which may be  explained by the ordering of Ta for y > 0.15 suggesting the transformation to another  space group. The appearance of absorption peak in the infrared absorption spectra of K0.3TayW1-yO3, y > 0.10 samples indicate the transition to non-metallic phase. DOI: http://dx.doi.org/10.3329/jbcs.v25i1.11770 Journal of Bangladesh Chemical Society, Vol. 25(1), 38-45, 2012

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