scholarly journals Synthesis, PtS-type structure, and anomalous mechanics of the Cd(CN)2 precursor Cd(NH3)2[Cd(CN)4]

2018 ◽  
Vol 47 (21) ◽  
pp. 7263-7271 ◽  
Author(s):  
Chloe S. Coates ◽  
Joshua W. Makepeace ◽  
Andrew G. Seel ◽  
Mia Baise ◽  
Ben Slater ◽  
...  
Keyword(s):  
Liquid Ammonia ◽  
Type Structure ◽  
Cadmium Metal ◽  
Nonaqueous Synthesis

We report the nonaqueous synthesis of Cd(CN)2 by oxidation of cadmium metal with Hg(CN)2 in liquid ammonia.

scholarly journals Synthesis, PtS-Type Structure, and Anomalous Mechanics of the Cd(CN)2 Precursor Cd(NH3)2[Cd(CN)4]

2018 ◽  
Author(s):  
Andrew Goodwin ◽  
Chloe Coates ◽  
Joshua Makepeace ◽  
Andrew Seel ◽  
Mia Baise ◽  
...  
Keyword(s):  
Density Functional ◽  
Mechanical Response ◽  
Variable Temperature ◽  
Negative Thermal Expansion ◽  
Process Variable ◽  
X Ray Diffraction ◽  
Prolonged Heating ◽  
X Ray ◽  
Cadmium Metal ◽  
Nonaqueous Synthesis

We report the nonaqueous synthesis of Cd(CN)<sub>2</sub> by oxidation of cadmium metal with Hg(CN)<sub>2</sub> in liquid ammonia. The reaction proceeds <i>via</i> an intermediate of composition Cd(NH<sub>3</sub>)<sub>2</sub>[Cd(CN)<sub>4</sub>], which converts to Cd(CN)<sub>2</sub> on prolonged heating. Powder X-ray diffraction measurements allow us to determine the crystal structure of the previously-unreported Cd(NH<sub>3</sub>)<sub>2</sub>[Cd(CN)<sub>4</sub>], which we find to adopt a twofold interpenetrating PtS topology. We discuss the effect of partial oxidation on the Cd/Hg composition of this intermediate, as well as its implications for the reconstructive nature of the deammination process. Variable-temperature X-ray diffraction measurements allow us to characterise the anisotropic negative thermal expansion (NTE) behaviour of Cd(NH<sub>3</sub>)<sub>2</sub>[Cd(CN)<sub>4</sub>] together with the effect of Cd/Hg substitution; <i>ab initio</i> density functional theory (DFT) calculations reveal a similarly anomalous mechanical response in the form of both negative linear compressibility (NLC) and negative Poisson's ratios.

scholarly journals Darstellung und Kristallstruktur des Cs2Se5 mit einer Anmerkung zum Rb2TeSe4

1985 ◽  
Vol 40 (7) ◽  
pp. 895-899 ◽  
Author(s):  
Uwe Kretschmann ◽  
Peter Böttcher
Keyword(s):  
Liquid Ammonia ◽  
Type Structure ◽  
Melting Reaction ◽  
Trans Conformation ◽  
Space Group ◽  
Structure Space

Cs2Se5 results from the reaction of the elements in liquid ammonia. It crystallizes with the K2S5- type structure (space group P212121; Z = 4). The cell constants are as follows: a - 7.420(2) Å , b - 18.879(4) Å , c = 7.105(1) Å. The structure is characterized by unbranched chains Se52- with a trans conformation. Rb2TeSe4 is synthesized from a mixture of Rb2Se3, Se, and Te (melting-reaction, 600 °C, 5 days). Its structure is isotypic with Rb2Te5 (space group C2/m, Z = 2). The cell constants are: a = 11.473(3) Å , b - 8.590(1) Å, c = 5.253(1) Å, β = 119.75(2)°. The structure contains an infinite polyanion of sixmembered rings of tellurium and selenium, connected via common vertices.

scholarly journals Synthesis, PtS-Type Structure, and Anomalous Mechanics of the Cd(CN)2 Precursor Cd(NH3)2[Cd(CN)4]

2018 ◽  
Author(s):  
Andrew Goodwin ◽  
Chloe Coates ◽  
Joshua Makepeace ◽  
Andrew Seel ◽  
Mia Baise ◽  
...  
Keyword(s):  
Density Functional ◽  
Mechanical Response ◽  
Variable Temperature ◽  
Negative Thermal Expansion ◽  
Process Variable ◽  
X Ray Diffraction ◽  
Prolonged Heating ◽  
X Ray ◽  
Cadmium Metal ◽  
Nonaqueous Synthesis

We report the nonaqueous synthesis of Cd(CN)<sub>2</sub> by oxidation of cadmium metal with Hg(CN)<sub>2</sub> in liquid ammonia. The reaction proceeds <i>via</i> an intermediate of composition Cd(NH<sub>3</sub>)<sub>2</sub>[Cd(CN)<sub>4</sub>], which converts to Cd(CN)<sub>2</sub> on prolonged heating. Powder X-ray diffraction measurements allow us to determine the crystal structure of the previously-unreported Cd(NH<sub>3</sub>)<sub>2</sub>[Cd(CN)<sub>4</sub>], which we find to adopt a twofold interpenetrating PtS topology. We discuss the effect of partial oxidation on the Cd/Hg composition of this intermediate, as well as its implications for the reconstructive nature of the deammination process. Variable-temperature X-ray diffraction measurements allow us to characterise the anisotropic negative thermal expansion (NTE) behaviour of Cd(NH<sub>3</sub>)<sub>2</sub>[Cd(CN)<sub>4</sub>] together with the effect of Cd/Hg substitution; <i>ab initio</i> density functional theory (DFT) calculations reveal a similarly anomalous mechanical response in the form of both negative linear compressibility (NLC) and negative Poisson's ratios.

New semiconducting compounds of diamond type structure

Physica ◽  
1954 ◽  
Vol 3 (7-12) ◽  
pp. 1107-1109 ◽  
Author(s):  
C GOODMAN ◽  
R DOUGLAS
Keyword(s):  
Type Structure ◽  
Semiconducting Compounds ◽  
Diamond Type

Ammonolysis of titanium tetrachloride in liquid ammonia

1976 ◽  
Vol 73 ◽  
pp. 849-851 ◽  
Author(s):  
Thomas Kottarathil ◽  
Gérard Lepoutre
Keyword(s):  
Liquid Ammonia ◽  
Titanium Tetrachloride

Study of Natural Minerals of U-Ryrochlore-Type Structure as Analogues of Plutonium Ceramic Waste-form

2002 ◽  
Vol 713 ◽  
Author(s):  
Roman V. Bogdanov ◽  
Yuri F. Batrakov ◽  
Elena V. Puchkova ◽  
Andrey S. Sergeev ◽  
Boris E. Burakov
Keyword(s):  
Chemical Shifts ◽  
Pyrochlore Structure ◽  
Type Structure ◽  
Waste Form ◽  
X Ray ◽  
Ceramic Waste ◽  
Natural Minerals ◽  
The Us ◽  
Pyrochlore Type

ABSTRACTAt present, crystalline ceramic based on titanate pyrochlore, (Ca,Gd,Hf,Pu,U)2Ti2O7, is considered as the US candidate waste form for the immobilization of weapons grade plutonium. Naturally occuring U-bearing minerals with pyrochlore-type structure: hatchettolite, betafite, and ellsworthite, were studied in orders to understand long-term radiation damage effects in Pu ceramic waste forms. Chemical shifts (δ) of U(Lδ1)– and U(Lβ1) – X-ray emission lines were measured by X-ray spectrometry. Calculations were performed on the basis of a two-dimensional δLá1- and δLδ1- correlation diagram. It was shown that 100% of uranium in hatchettolite and, probably, 95-100% of uranium in betafite are in the form of (UO2)2+. formal calculation shows that in ellsworthite only 20% of uranium is in the form of U4+ and 80% of the rest is in the forms of U5+ and U6+. The conversion of the initial U4+ ion originally occurring in the pyrochlore structure of natural minerals to (UO2)2+ due to metamict decay causes a significant increase in uranium mobility.

SEARCH FOR A NEW MANAGEMENT MODEL FOR THE DEVELOPMENT, PRODUCTION AND IMPLEMENTATION OF WORLD-CLASS HYDROGEN TECHNOLOGIES

2020 ◽  
Vol 3 (7) ◽  
pp. 114-119
Author(s):  
V. F. UKOLOV ◽  
◽  
E. N. OZHIGANOV ◽  
Yu. V. RAGULINA ◽  
V. V. ARKHIPOV ◽  
...  
Keyword(s):  
Large Scale ◽  
The State ◽  
Type Structure ◽  
Management Model ◽  
World Class ◽  
Hydrogen Technologies

After the research, the authors came to the conclusion: it is necessary to get a new, interstate platform-type structure for the development, production and large-scale implementation of civil hydrogen technologies for various fields of activity and the state.

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