The role of ?ideal? and ?real? crystal structure in the solid-state decomposition of silver oxalate: Experimental diffraction studies and theoretical calculations

1997 ◽  
Vol 101-103 ◽  
pp. 1315-1320 ◽  
Author(s):  
D NAUMOV
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Theoretical Calculations ◽  
Real Crystal ◽  
Solid State Decomposition ◽  
Silver Oxalate

scholarly journals The role of MgB12H12 in the hydrogen desorption process of Mg(BH4)2

2015 ◽  
Vol 51 (4) ◽  
pp. 700-702 ◽  
Author(s):  
Yigang Yan ◽  
Arndt Remhof ◽  
Daniel Rentsch ◽  
Andreas Züttel
Keyword(s):  
Solid State ◽  
Hydrogen Desorption ◽  
Decomposition Process ◽  
Desorption Process ◽  
Solid State Decomposition

Throughout the solid-state decomposition process of Mg(BH4)2, the MgB12H12 phase does not exist in the solid residues after decomposition.

scholarly journals Formation of interstellar propanal and 1-propanol ice: a pathway involving solid-state CO hydrogenation

2019 ◽  
Vol 627 ◽  
pp. A1 ◽  
Author(s):  
D. Qasim ◽  
G. Fedoseev ◽  
K.-J. Chuang ◽  
V. Taquet ◽  
T. Lamberts ◽  
...  
Keyword(s):  
Solid State ◽  
Co Hydrogenation ◽  
Theoretical Calculations ◽  
Interstellar Space ◽  
Activation Barriers ◽  
Reflection Absorption Infrared Spectroscopy ◽  
Core Phase ◽  
Temperature Programmed ◽  
Freeze Out

Context. 1-propanol (CH3CH2CH2OH) is a three carbon-bearing representative of the primary linear alcohols that may have its origin in the cold dark cores in interstellar space. To test this, we investigated in the laboratory whether 1-propanol ice can be formed along pathways possibly relevant to the prestellar core phase. Aims. We aim to show in a two-step approach that 1-propanol can be formed through reaction steps that are expected to take place during the heavy CO freeze-out stage by adding C2H2 into the CO + H hydrogenation network via the formation of propanal (CH3CH2CHO) as an intermediate and its subsequent hydrogenation. Methods. Temperature programmed desorption-quadrupole mass spectrometry (TPD-QMS) was used to identify the newly formed propanal and 1-propanol. Reflection absorption infrared spectroscopy (RAIRS) was used as a complementary diagnostic tool. The mechanisms that can contribute to the formation of solid-state propanal and 1-propanol, as well as other organic compounds, during the heavy CO freeze-out stage are constrained by both laboratory experiments and theoretical calculations. Results. Here it is shown that recombination of HCO radicals formed upon CO hydrogenation with radicals formed via C2H2 processing – H2CCH and H3CCH2 – offers possible reaction pathways to solid-state propanal and 1-propanol formation. This extends the already important role of the CO hydrogenation chain to the formation of larger complex organic molecules. The results are compared with ALMA observations. The resulting 1-propanol:propanal ratio concludes an upper limit of <0.35−0.55, which is complemented by computationally derived activation barriers in addition to the experimental results.

scholarly journals Solid state forms of 4-aminoquinaldine – from void structures with and without solvent inclusion to close packing

CrystEngComm ◽  
2015 ◽  
Vol 17 (12) ◽  
pp. 2504-2516 ◽  
Author(s):  
Doris E. Braun ◽  
Thomas Gelbrich ◽  
Volker Kahlenberg ◽  
Ulrich J. Griesser
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Carbon Tetrachloride ◽  
Structure Prediction ◽  
Experimental Studies ◽  
Close Packing ◽  
Crystal Structure Prediction ◽  
Role Of Solvent

Crystal structure prediction combined with experimental studies unveil the structural and thermodynamic features of three non-solvated forms and a carbon tetrachloride solvate of 4-aminoquinaldine and provide intriguing insights into void structures and the role of solvent inclusion.

Synthesis, crystal structure, and photoluminescence of a dumbbell-like sodium dicyanamide compound with 15-crown-5

2017 ◽  
Vol 72 (2) ◽  
pp. 167-170 ◽  
Author(s):  
Xi Liu ◽  
Wen-Juan Ru ◽  
Zhen Zhao
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Coordination Mode ◽  
Theoretical Calculations ◽  
Emission Mechanism ◽  
Gaseous Diffusion ◽  
Violet Luminescence

AbstractGaseous diffusion of n-hexane into the reaction mixture of sodium dicyanamide NaN(CN)2 with 15-crown-5 in tetrahydrofuran leads to a sodium dicyanamide compound [Na(15-crown-5)]N(CN)2 (1). Compound 1 exhibits a centrosymmetric dumbbell-like structure constructed by dicyanamide ligands double-bridging [Na(15-crown-5)]+ moieties with a μ-1,5 coordination mode. Solid-state photoluminescence experiments have shown that compound 1 emits violet luminescence, and its possible emission mechanism was investigated in detail based on theoretical calculations.

scholarly journals Effect of Annealing on the Crystal Structure of COSI2/SI(100) Formed By MBE, SSE and RE Epitaxy Techniques

2019 ◽  
Vol 9 (1) ◽  
pp. 4813-4818
Keyword(s):  
Thin Film ◽  
Crystal Structure ◽  
Heat Treatment ◽  
Solid State ◽  
Molecular Beam ◽  
Growth Conditions ◽  
Cobalt Ions ◽  
State Diagrams ◽  
Silicon Doped

The paper reports a number of new original experimental results related to the study of the effect of annealing on the crystal structure of the surface of silicon doped with cobalt ions. The results of studies of the CoSi2 /Si(100) epitaxial structures formed by molecular beam epitaxy (MBE), solid state epitaxy (SSE), and other techniques are presented. Relations between morphology, stoichiometry, and growth conditions of CoSi2 / Si structures were established. The ratio of the intensities of the Auger signals of cobalt and silicon in the CoSi2 film, as well as silicon in CoSi2 and the silicon substrate was determined by the Auger profile of the sample. The authors determined that under certain conditions of heat treatment of the radiation on the surface of a single crystal, the so-called epitaxial silicides are formed which can play the role of conductive layers or metal coated. The structural state diagrams of CoSi2 / Si (100) thin-film systems formed by the MBE, SSE and other methods were compiled..

scholarly journals Enaminone Substituted Resorcin[4]arene—Sealing of an Upper-Rim with a Directional System of Hydrogen-Bonds

2020 ◽  
Vol 21 (20) ◽  
pp. 7494
Author(s):  
Anna Szafraniec ◽  
Marcin Grajda ◽  
Hanna Jędrzejewska ◽  
Agnieszka Szumna ◽  
Waldemar Iwanek
Keyword(s):  
Crystal Structure ◽  
Experimental Data ◽  
Solid State ◽  
Hydrogen Bonds ◽  
Theoretical Calculations ◽  
The Other ◽  
Thermally Activated ◽  
Intramolecular Hydrogen ◽  
Semi Empirical ◽  
Upper Rim

The paper presents the synthesis of an enaminone resorcin[4]arene via a thermally activated o-quinomethide. The crystal structure indicates that in the solid state all enaminone units participate in a unidirectional seam of 12 intramolecular hydrogen bonds that are formed around the cavity. The molecule exhibits C2 symmetry, with two opposite-laying enaminone units directed inside the cavity (“in”), and the other two units outside the cavity (“out”). In the solution the enaminone resorcin[4]arene exists as a mixture of conformers with distribution controlled by temperature and solvent. The experimental data are compared with the results of theoretical calculations using DFT B3LYP/6-31G(d,p) and fast semi-empirical DFTB/GFN2-xTB method in various solvents.

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