Thermal Decomposition of Alliin, the Major Flavor Component of Garlic, in an Aqueous Solution

1993 ◽  
pp. 144-152 ◽  
Author(s):  
Tung-Hsi Yu ◽  
Chi-Kuen Shu ◽  
Chi-Tang Ho
Keyword(s):  
Aqueous Solution ◽  
Thermal Decomposition ◽  
Flavor Component

Preparation and characterisation of vanadium pentoxide supported rhodium catalyst

1988 ◽  
Vol 46 ◽  
pp. 946-947
Author(s):  
A. Legrouri
Keyword(s):  
Aqueous Solution ◽  
Thermal Decomposition ◽  
Physicochemical Properties ◽  
Surface Area ◽  
Vanadium Pentoxide ◽  
High Purity ◽  
Gas Adsorption ◽  
Rhodium Catalyst ◽  
Optical Methods ◽  
Reducible Oxides

The industrial importance of metal catalysts supported on reducible oxides has stimulated considerable interest during the last few years. This presentation reports on the study of the physicochemical properties of metallic rhodium supported on vanadium pentoxide (Rh/V2O5). Electron optical methods, in conjunction with other techniques, were used to characterise the catalyst before its use in the hydrogenolysis of butane; a reaction for which Rh metal is known to be among the most active catalysts.V2O5 powder was prepared by thermal decomposition of high purity ammonium metavanadate in air at 400 °C for 2 hours. Previous studies of the microstructure of this compound, by HREM, SEM and gas adsorption, showed it to be non— porous with a very low surface area of 6m2/g3. The metal loading of the catalyst used was lwt%Rh on V2Q5. It was prepared by wet impregnating the support with an aqueous solution of RhCI3.3H2O.

Kinetics and Mechanism of the Thermal Decomposition of Hexaamminecobalt(III) and Aquopentaamminecobalt(III) Ions in Acidic Aqueous Solution

1974 ◽  
Vol 52 (15) ◽  
pp. 2751-2759 ◽  
Author(s):  
Anthony Martin Newton ◽  
Thomas Wilson Swaddle
Keyword(s):  
Aqueous Solution ◽  
Thermal Decomposition ◽  
Rate Coefficient ◽  
Initial Step ◽  
Hydrogen Ion ◽  
Minor Amount ◽  
Acidic Aqueous Solution ◽  
First Order ◽  
Independent Path ◽  
A Minor

The initial step in the thermal decomposition of Co(NH3)63+ in acidic aqueous solution is the replacement of NH3 by H2O, which occurs by a hydrogen-ion independent path, first order in complex, with rate coefficient k1 = 7.9 × 10−5 s−1 (140.4°), ΔH* = 36.6 kcal mol−1 and ΔS* = 10.7 cal deg−1 mol−1 in 0.1 M HClO4. For Co(NH3)5OH23+, there is a similar initial aquation path with k1 = 12.6 × 10−5 s−1 (140.6°), ΔH* = 41.9 kcal mol−1 and ΔS* = 24 cal deg−1 mol−1 and also a path first order in complex but inverse first order in [H+] with k2′ = 6.2 × 10−1 M s−1 (140.6°), ΔH* = 43.5 kcal mol−1 and ΔS* = 26.7 cal deg−1 mol−1 in perchlorate media of ionic strength 1.0 M. The effects of electrolyte type and concentration on the rates of these reactions have been examined. Subsequent aquation steps are relatively rapid because of the predominance of inversely [H+]-dependent pathways and are followed by redox to Co(H2O)62+, NH4+, N2, N2O, and a minor amount of O2. A mechanism involving OH and NH2 radicals is proposed for the redox step.

Optimizing the silanization of thermally-decomposed iron oxide nanoparticles for efficient aqueous phase transfer and MRI applications

RSC Advances ◽  
2016 ◽  
Vol 6 (96) ◽  
pp. 93784-93793 ◽  
Author(s):  
Xin-Yang Wang ◽  
Damien Mertz ◽  
Cristina Blanco-Andujar ◽  
Anindita Bora ◽  
Mathilde Ménard ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Thermal Decomposition ◽  
Iron Oxide ◽  
Iron Oxide Nanoparticles ◽  
Aqueous Phase ◽  
Phase Transfer ◽  
Oxide Nanoparticles

A facile silanization method allows to efficiently stabilise in aqueous solution iron oxide NPs synthesized by thermal decomposition for MRI applications.

Preparation and Thermal Decomposition of the Polyoxometalate Complexes of Ciprofloxacin with HnXW12O40 (X=B, Si, P)

2011 ◽  
Vol 335-336 ◽  
pp. 1075-1078
Author(s):  
Dun Jia Wang ◽  
Yan Fang Kang ◽  
Ben Po Xu
Keyword(s):  
Aqueous Solution ◽  
Thermal Decomposition ◽  
Functional Group ◽  
Heteropoly Acids ◽  
X Ray Diffraction ◽  
Keggin Anion ◽  
Characteristic Functional ◽  
X Ray ◽  
Dta Curves ◽  
Preparation And Thermal Decomposition

The polyoxometalate complexes of ciprofloxacin with HnXW12O40(X=B, Si, P) were prepared from ciprofloxacin hydrochloride and HnXW12O40·nH2O (X=B, Si, P) in aqueous solution, and characterized by elemental analysis, IR spectra and TG-DTA. The IR spectrum confirmed the presence of Keggin-type anion of heteropoly acids and the characteristic functional group of ciprofloxacin after the polyoxometalate complexes are formed. The TG/DTA curves showed that their thermal decomposition was a more-steps process consisting of simultaneous processes involving also Keggin anion. The residue of decomposition is a mixture of WO3and B2O3, SiO2or P2O5, confirmed by X-ray diffraction and IR spectroscopy. And the possible thermal decomposition mechanisms of the complexes are proposed.

Synthese und Kristallstruktur von Dinatrium-di-μ/-oxo-bis[trihydroxo-methylantimonat(V)] / Synthesis and Crystal Structure of Disodium-di-μ-oxo-bis[trihydroxo-methylantimonate(V)]

1991 ◽  
Vol 46 (2) ◽  
pp. 139-142 ◽  
Author(s):  
Markus Wieber ◽  
Udo Simonis ◽  
Dieter Kraft
Keyword(s):  
Crystal Structure ◽  
Aqueous Solution ◽  
Hydrogen Peroxide ◽  
Thermal Decomposition ◽  
Sodium Hydroxide ◽  
Spectroscopic Properties ◽  
Membered Ring ◽  
Dimeric Molecule ◽  
Synthesis And Crystal Structure

The oxidation of dialkoxymethylstibine with hydrogen peroxide in the presence of sodium hydroxide leads to the formation of disodium-di-μ-oxo-bis[trihydroxo-methylantimonate(V)]. The salt can be synthesized also by dissolving methanestibonic acid in an aqueous solution of sodium hydroxide. The crystal structure has been determined; it shows a dimeric molecule containing a four-membered ring with Sb -O -Sb linkages. Thermal decomposition and spectroscopic properties o f the com pound are discussed.

Synthesen, Kristallstrukturen und Eigenschaften von Trisilber-und Trikalium-tri-μ-imido-cyclotriphosphat, Ag3(PO2NH)3 und K3(PO2NH)3 / Syntheses, Crystal Structures, and Properties of Trisilver and Tripotassium Tri-μ-im ido Cyclotriphosphate, Ag3(PO2NH)3 and K3(PO2NH)3

1997 ◽  
Vol 52 (2) ◽  
pp. 251-255 ◽  
Author(s):  
N. Stock ◽  
W. Schnick
Keyword(s):  
Aqueous Solution ◽  
Thermal Decomposition ◽  
Nitrogen Atom ◽  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Chair Conformation ◽  
X Ray ◽  
Diffusion Controlled ◽  
Structures And Properties ◽  
Ray Methods

Abstract Coarse crystalline Ag3(PO2NH)3 (1) and K3(PO2NH)3 (2) are obtained by addition of an aqueous solution of AgNO3 to an acidified solution of Na3(PO2NH)3 · 4H2O and by diffusion controlled addition of ethanol to a solution of K3(PO2NH)3 in water, respectively. The crystal structures of 1 and 2 have been determined by single crystal X-ray methods (Ag3(PO2NH)3: P21/c; a = 1166.6(1), b = 786.4(1), c = 997.8(1) pm, β = 106.91(1)°; Z = 4. K3(PO2NH)3: R3̄; a = 1271.4(2), c = 1017.9(2) pm, Z = 6). In Ag3(PO2NH)3 the cyclic anion is markedly distorted because of interactions between Ag+ and one nitrogen atom of the anion. In K3(PO2NH)3 the trimetaphosphimate ring shows a chair conformation and two cyclic anions are connected to each other by hydrogen bonds. DTA/TG investigations show thermal decomposition above 275 and 250 °C for 1 and 2, respectively.

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