REACTIONS OF CYANOGEN IODIDE

1953 ◽  
Vol 31 (10) ◽  
pp. 923-936
Author(s):  
L. E. Bodnar ◽  
A. B. Van Cleave
Keyword(s):  
Carbon Dioxide ◽  
Aqueous Solution ◽  
Reaction Mechanism ◽  
Hydrogen Chloride ◽  
Ammonium Chloride ◽  
Starting Material ◽  
Iodine Monochloride ◽  
Reaction Products ◽  
Catalyzed Reactions ◽  
Cyanogen Iodide

A series of hydrogen chloride catalyzed reactions involving cyanogen iodide as the starting material have been investigated in dioxane and in aqueous solution at 30°and 45 °C. The course of the reaction was followed by determining the decrease in the number of oxidation equivalents present. Reaction products identified were: iodine monochloride, iodine, ammonium chloride, and carbon dioxide. A possible reaction mechanism has been suggested.

THE HYDROLYSIS AND POLYMERIZATION OF CYANOGEN CHLORIDE IN THE PRESENCE OF HYDROGEN CHLORIDE

1947 ◽  
Vol 25b (5) ◽  
pp. 430-439 ◽  
Author(s):  
A. B. Van Cleave ◽  
H. E. Mitton
Keyword(s):  
Carbon Dioxide ◽  
Hydrochloric Acid ◽  
Hydrogen Chloride ◽  
Ammonium Chloride ◽  
Pressure Increase ◽  
Polymerization Reaction ◽  
Cyanogen Chloride ◽  
Rate Of Hydrolysis ◽  
Acid Catalyzed ◽  
Autocatalytic Effect

Cyanogen chloride reacts quantitatively with water in the presence of hydrochloric acid according to the equation: CNCl + 2H2O → CO2 + NH4Cl. As the percentage of hydrochloric acid is reduced towards zero, the rate of hydrolysis at 30 °C. becomes exceedingly slow. The rate of hydrolysis, as indicated by the pressure increase, shows an increase with time which is particularly marked when the concentration of hydrogen chloride is less than 1%. This apparent autocatalytic effect is not due to the accumulation of solid ammonium chloride. A polymerization reaction, the rate of which is increased by the addition of dry hydrogen chloride, proceeds simultaneously with the hydrolysis reaction. Pure cyanogen chloride shows little or no tendency to polymerize at 30 °C. Carbon dioxide has been shown to be quite soluble in liquid cyanogen chloride and an explanation has been suggested for the form of the pressure vs. time curves obtained in studying the acid catalyzed hydrolysis and polymerization of cyanogen chloride.

Atom Condensed Fukui Function for Condensed Phases and Biological Systems and Its Application to Enzymatic Fixation of Carbon Dioxide

2019 ◽  
Author(s):  
Javier Oller ◽  
David A. Sáez ◽  
Esteban Vöhringer-Martinez
Keyword(s):  
Carbon Dioxide ◽  
Aqueous Solution ◽  
Molecular System ◽  
Chemical Reactivity ◽  
Nucleophilic Attack ◽  
Stable Conformation ◽  
Fukui Functions ◽  
Reactivity Descriptors ◽  
Dynamics Simulations ◽  
Fixation Of Carbon Dioxide

<div><div><div><p>Local reactivity descriptors such as atom condensed Fukui functions are promising computational tools to study chemical reactivity at specific sites within a molecule. Their applications have been mainly focused on isolated molecules in their most stable conformation without considering the effects of the surroundings. Here, we propose to combine QM/MM Born-Oppenheimer molecular dynamics simulations to obtain the microstates (configurations) of a molecular system using different representations of the molecular environment and calculate Boltzmann weighted atom condensed local reac- tivity descriptors based on conceptual DFT. Our approach takes the conformational fluctuations of the molecular system and the polarization of its electron density by the environment into account allowing us to analyze the effect of changes in the molecular environment on reactivity. In this contribution, we apply the method mentioned above to the catalytic fixation of carbon dioxide by crotonyl-CoA carboxylase/reductase and study if the enzyme alters the reactivity of its substrate compared to an aqueous solution. Our main result is that the protein en- vironment activates the substrate by the elimination of solute-solvent hydrogen bonds from aqueous solution in the two elementary steps of the reaction mechanism: the nucleophilic attack of a hydride anion from NADPH on the α, β unsaturated thioester and the electrophilic attack of carbon dioxide on the formed enolate species.</p></div></div></div>

Chlorination of 2,4,6-trichlorophenol in acidic aqueous medium

1985 ◽  
Vol 50 (8) ◽  
pp. 1842-1851 ◽  
Author(s):  
Petr Švec
Keyword(s):  
Reaction Mechanism ◽  
Aqueous Medium ◽  
Hydrogen Chloride ◽  
Reaction Medium ◽  
Model Experiments ◽  
Sulfuric And Hydrochloric Acids

The course of chlorination of 2,4,6-trichlorophenol (I) in water and approximately 20% sulfuric and hydrochloric acids has been investigated. In all these media the reaction gives primarily 2,4,6,6-tetrachloro-2,4-cyclohexadienone (II) which is subsequently chlorinated under formation of polychlorinated alicyclic ketones or isomerized to give the more stable 2,4,6,6-tetrachloro-2,5-cyclohexadienone (III), the precursor of further arising chlorinated 1,4-benzoquinones. The ratio of the arising polychlorinated alicyclic ketones to chlorinated 1,4-benzoquinones is significantly influenced by concentration of hydrogen chloride in the reaction medium. On the basis of model experiments, the reaction mechanism of exhaustive chlorination of 2,4,6-trichlorophenol has been suggested.

Photooxidation at Platinum Colloidal TiO2 Aqueous-Solution Interfaces. I. Ethylenediaminetetraacetic Acid and Related-Compounds

1986 ◽  
Vol 39 (5) ◽  
pp. 757 ◽  
Author(s):  
DN Furlong ◽  
D Wells ◽  
WHF Sasse
Keyword(s):  
Carbon Dioxide ◽  
Aqueous Solution ◽  
Ethylenediaminetetraacetic Acid ◽  
Oxidation Potential ◽  
Illumination Time ◽  
Carbonium Ions ◽  
Production Of Hydrogen ◽  
Glycine Derivatives ◽  
Lactic Acids ◽  
Exhaustive Oxidation

The photooxidation of ethylenediaminetetraacetic acid ( edta ) and related glycine derivatives, at Pt/TiO2/aqueous solution interfaces, has been monitored via the production of hydrogen and carbon dioxide. Yields are consistent with the exhaustive oxidation of methoxycarbonyl groups and the rate varied with the number and distribution of such groups. A photooxidation pathway is proposed which involves the oxidation of intermediate carbonium ions. Plausible molecular intermediates, such as formic acid and formaldehyde in the case of edta , have been shown in separate experiments to be photooxidized according to the proposed pathway. The maximum rate of oxidation for each donor depends on its oxidation potential and its tendency to adsorb on TiO2 surfaces. Desorption due to pH increase, as well as consumption of the donor, causes the rate to decline rapidly with illumination time. Acetic and malonic acids gave some hydrogen but underwent mainly (> c. 80%) photo-Kolbe decarboxylation to yield carbon dioxide and methane. By contrast the oxidation of oxomalonic, pyruvic and lactic acids proceeded mainly via a H2 producing pathway similar to that established for edta. The oxidation of pyruvic and lactic acids ceased at a yield of one mole of CO2 per mole of acid.

Notizen:Phosphorescence Decay in Thallium-Doped Ammonium Chloride

1978 ◽  
Vol 33 (10) ◽  
pp. 1241-1242 ◽  
Author(s):  
S. Chaudhari ◽  
T. R. Joshi ◽  
R. V. Joshi
Keyword(s):  
Aqueous Solution ◽  
Ammonium Chloride ◽  
Mechanical Treatment ◽  
Room Temperature ◽  
Host Lattice ◽  
Luminescence Decay ◽  
Decay Rates ◽  
Negative Ion ◽  
Ultraviolet Emission ◽  
Near Ultraviolet

Abstract The phosphorescence decay rates of thallium-doped ammonium chloride (NH4Cl:Tl) phosphors, prepared by crystallization from aqueous solution, have been studied at room temperature for near-ultraviolet emission. The effects of impurity concentration as well as thermal and/or mechanical treatment on the decay rates have been examined. Phosphorescence centres consisting of a Tl+ion and a nearby negative ion vacancy are suggested to be responsible for the observed luminescence decay. The changes in the decay characteristics after pretreatments are explained on the basis of the location of the centres in normal and distorted regions of the host lattice.

Chemical Absorption of Carbon Dioxide into Aqueous Solution of Potassium Threonate

2010 ◽  
Vol 45 (4) ◽  
pp. 497-507 ◽  
Author(s):  
Kyu-Suk Hwang ◽  
Dae-Won Park ◽  
Kwang-Joong Oh ◽  
Seong-Soo Kim ◽  
Sang-Wook Park
Keyword(s):  
Carbon Dioxide ◽  
Aqueous Solution ◽  
Chemical Absorption

Reaction Mechanism of Perovskite KNbO3 in Aqueous Solution

2003 ◽  
Vol 248 ◽  
pp. 27-30
Author(s):  
Kenji Toda ◽  
Saori Tokuoka ◽  
Naotaka Ohtake ◽  
Kazuyoshi Uematsu ◽  
Mineo Sato
Keyword(s):  
Aqueous Solution ◽  
Reaction Mechanism
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