A kinetic study of the influence of alcohols on the nitrosation of morpholine in acid media. Equilibrium constants for the formation of alkyl nitrites

1984 ◽  
Vol 62 (1) ◽  
pp. 136-138 ◽  
Author(s):  
Julio Casado ◽  
Francisco Manuel Lorenzo ◽  
Manuel Mosquera ◽  
Maria Flor Rodriguez Prieto
Keyword(s):  
Kinetic Study ◽  
Nitrous Acid ◽  
Kinetic Data ◽  
Catalytic Effect ◽  
Equilibrium Constants ◽  
Inhibitory Effect ◽  
Aliphatic Alcohols ◽  
Acid Media ◽  
Alkyl Nitrites ◽  
Alkyl Nitrite

The effect of the aliphatic alcohols methanol, ethanol, propanol, isopropanol, 2-butanol, isobutanol, and tert-butanol on the rate of nitrosation of morpholine at pH 3 and 25 °C has been studied. The inhibition observed is attributed to the formation of alkyl nitrites, which are poor nitrosating agents in acid media. The equilibrium constants for the formation of alkyl nitrites from nitrous acid and alcohols have been calculated both spectrophotometrically and from kinetic data for the inhibitory effect, and there is agreement between the two sets of results. The molar absorptivities at 265 nm of the alkyl nitrites have also been determined. When the concentration of alkyl nitrite is very low, a slight catalytic effect considered to be an effect of the medium has been observed.

Reesterification of ethyl acetate by propanol catalysed by glycidyl methacrylate copolymers containing sulphonic acid groups

1981 ◽  
Vol 46 (8) ◽  
pp. 1941-1946 ◽  
Author(s):  
Karel Setínek
Keyword(s):  
Liquid Phase ◽  
Ethyl Acetate ◽  
Kinetic Study ◽  
Gas Phase ◽  
Nonlinear Regression ◽  
Kinetic Data ◽  
Glycidyl Methacrylate ◽  
Kinetic Equations ◽  
Methacrylate Copolymers ◽  
Styrene Divinylbenzene

A series of differently crosslinked macroporous 2,3-epoxypropyl methacrylate-ethylenedimethacrylate copolymers with chemically bonded propylsulphonic acid groups were used as catalysts for the kinetic study of reesterification of ethyl acetate by n-propanol in the liquid phase at 52 °C and in the gas phase at 90 °C. Analysis of kinetic data by the method of nonlinear regression for a series of equations of the Langmuir-Hinshelwood type showed that kinetic equations which describe best the course of the reaction are the same as for the earlier studied sulphonated macroporous styrene-divinylbenzene copolymers. Compared types of catalysts differ, however, in the dependence of their activity on the degree of crosslinking of the copolymer used.

Surface catalytic effect of liposome formation on lecithin-iodine interaction. A kinetic study

Langmuir ◽  
1989 ◽  
Vol 5 (4) ◽  
pp. 1035-1037
Author(s):  
Ira Chatterjee ◽  
Benoy B. Bhowmik ◽  
Papiya Nandy
Keyword(s):  
Kinetic Study ◽  
Catalytic Effect

Performance of Chitosan Micro/Nanoparticles to Remove Hexavalent Chromium From Residual Water

2017 ◽  
pp. 262-288
Author(s):  
Jimena Bernadette Dima ◽  
Noemí Zaritzky
Keyword(s):  
Chemical Analysis ◽  
Hexavalent Chromium ◽  
Kinetic Data ◽  
Chitosan Nanoparticles ◽  
Living Systems ◽  
Cross Linking ◽  
Residual Water ◽  
Acid Media ◽  
Best Fitting ◽  
Pseudo Second Order

Hexavalent chromium Cr(VI) is toxic to living systems and must be removed from wastewater. Chitosan is a cationic, biocompatible, biodegradable, biopolymer obtained from marine wastes. The performance of chitosan particles (CH) and chitosan nanoparticles (CHN) to remove Cr(VI) from aqueous solutions is discussed in the present chapter. CHN were obtained by reticulation with tripolyphosphate (TPP), and physico-chemically characterized. The performance of CHN decreased at higher pH due to the cross-linking process with TPP. Langmuir isotherm described the equilibrium adsorption values and pseudo-second order rate provided the best fitting to the kinetic data. Chemical analysis to determine the oxidation state of the adsorbed Cr, showed that Cr(VI) was adsorbed on CH particles without further reduction; in contrast Cr(VI) removed from the solution was reduced and bound to the CHN as Cr(III). Chitosan crosslinking was essential to adsorb Cr(VI) at pH<3 due to the dissolution of CH in acid media.

scholarly journals HO<sub><i>x</i></sub> and NO<sub><i>x</i></sub> production in oxidation flow reactors via photolysis of isopropyl nitrite, isopropyl nitrite-d<sub>7</sub>, and 1,3-propyl dinitrite at <i>λ</i> = 254, 350, and 369 nm

2019 ◽  
Vol 12 (1) ◽  
pp. 299-311 ◽  
Author(s):  
Andrew T. Lambe ◽  
Jordan E. Krechmer ◽  
Zhe Peng ◽  
Jason R. Casar ◽  
Anthony J. Carrasquillo ◽  
...  
Keyword(s):  
Oxidation Products ◽  
Ionization Mass ◽  
Nitrite Concentration ◽  
Flow Reactors ◽  
Oxidative Aging ◽  
Complementary Method ◽  
Alkyl Nitrites ◽  
Aerosol Mass ◽  
Alkyl Nitrite

Abstract. Oxidation flow reactors (OFRs) are an emerging technique for studying the formation and oxidative aging of organic aerosols and other applications. In these flow reactors, hydroxyl radicals (OH), hydroperoxyl radicals (HO2), and nitric oxide (NO) are typically produced in the following ways: photolysis of ozone (O3) at λ=254 nm, photolysis of H2O at λ=185 nm, and via reactions of O(1D) with H2O and nitrous oxide (N2O); O(1D) is formed via photolysis of O3 at λ=254 nm and/or N2O at λ=185 nm. Here, we adapt a complementary method that uses alkyl nitrite photolysis as a source of OH via its production of HO2 and NO followed by the reaction NO + HO2 → NO2 + OH. We present experimental and model characterization of the OH exposure and NOx levels generated via photolysis of C3 alkyl nitrites (isopropyl nitrite, perdeuterated isopropyl nitrite, 1,3-propyl dinitrite) in the Potential Aerosol Mass (PAM) OFR as a function of photolysis wavelength (λ=254 to 369 nm) and organic nitrite concentration (0.5 to 20 ppm). We also apply this technique in conjunction with chemical ionization mass spectrometer measurements of multifunctional oxidation products generated following the exposure of α-Pinene to HOx and NOx obtained using both isopropyl nitrite and O3 + H2O + N2O as the radical precursors.

A kinetic study of phenol nitration and nitrosation with nitrous acid in the dark

2004 ◽  
Vol 2 (3) ◽  
pp. 135-139 ◽  
Author(s):  
Davide Vione ◽  
Simone Belmondo ◽  
Lorenzo Carnino
Keyword(s):  
Kinetic Study ◽  
Nitrous Acid

Reaction of Glutathione with Conjugated Carbonyls

1975 ◽  
Vol 30 (7-8) ◽  
pp. 466-473 ◽  
Author(s):  
Hermann Esterbauer ◽  
Helmward Zöllner ◽  
Norbert Scholz
Keyword(s):  
Catalytic Effect ◽  
Biological Activities ◽  
Equilibrium Constants ◽  
Reverse Reaction ◽  
Mesityl Oxide ◽  
Forward Reaction ◽  
First Order ◽  
First Order Kinetics ◽  
Proton Donors ◽  
The Stability

Abstract 1. GSH reacts with conjugated carbonyls according to the equation: G SH+R-CH=CH-COR⇆R-CH(SG)-CH2-COR. The forward reaction follows second order, the reverse reaction first order kinetics. It is assumed that this reaction reflects best the ability of conjugated carbonyls to inactivate SH groups in biological systems. 2. The rate of forward reaction increases with pH approx. parallel with αSH. Besides OH- ions also proton donors (e. g. buffers) increase the rate. The catalytic effect of pH and buffer is inter­ preted in view of the reaction mechanism. 3. The equilibrium constants as well as the rate constants for forward (k1) and reverse reaction show an extreme variation depending on the carbonyl structure. Acrolein and methyl vinyl ketone (kt = 120 and 32 mol-1 sec-1 , resp.) react more rapidly than any other carbonyl to give very stable adducts (half-lives for reverse reaction 4.6 and 60.7 days, resp.). Somewhat less reactive are 4-hydroxy-2-alkenals and 4-ketopentenoic acid (k1 between 1 and 3 mol-1 sec-1), but they also form very stable adducts showing half-lives between 3.4 and 19 days. All other carbonyl studied react either very slowly (e. g. citral, ethly crotonate, mesityl oxide, acrylic acid) or form very labile adducts (crotonal, pentenal, hexenal, 3-methyl-butenone). Comparing biological activities of con­ jugated carbonyls their reactivity towards HS (k1) and the stability of the adducts must be considered.

EFFECTS OF ALIPHATIC ALCOHOLS ON THE METABOLISM OF GLUCOSE AND FRUCTOSE IN RAT LIVER SLICES

1963 ◽  
Vol 41 (3) ◽  
pp. 793-803 ◽  
Author(s):  
Edward Majchrowicz ◽  
J. H. Quastel
Keyword(s):  
Rat Liver ◽  
Liver Slice ◽  
Inhibitory Effect ◽  
Aliphatic Alcohols ◽  
Isotopic Dilution ◽  
Acetyl Coa ◽  
Radioactive Carbon ◽  
Liver Slices ◽  
The Difference ◽  
Ethanol Ethanol

Ethanol, at concentrations up to 3 mM, whilst having little inhibitory effect on the production of respiratory CO2of rat liver slices, has a marked suppressing action on the formation of labelled CO2from labelled glucose. The suppression of C14O2formation by ethanol from radioactive glucose is independent of the concentration of the latter and amounts to 57% with 3 mM ethanol after 1 hour's incubation. The results are consistent with the conclusion that ethanol gives rise more rapidly than glucose to acetyl CoA and that the large suppressing action of ethanol in rat liver slices is due to isotopic dilution of labelled acetyl CoA derived from the labelled sugars with the unlabelled acetyl CoA derived from ethanol. Ethanol exercises a larger inhibition of the rate of C14O2formation from glucose-6-C14than from glucose-1-C14. The difference between the effects of ethanol on C14O2formation from glucose-1-C14and glucose-6-C14is presumably due to operation of the hexosemonophosphate shunt.The higher aliphatic alcohols have about the same diminishing effect on C14O2formation from glucose-U-C14and fructose-U-C14as does ethanol. This observation may also be a consequence of dilution of labelled acetyl CoA derived from the sugars by unlabelled acetyl CoA coming from the added alcohol. Incorporation of radioactive carbon from the labelled sugars into liver proteins and lipids is inhibited by ethanol and higher aliphatic alcohols, and the inhibitions are similar in magnitude to those of C14O2formation. These may be accounted for by isotopic dilution. The amounts of C14incorporated into lipids and proteins from radioactive glucose and fructose are small, being about 1/10th of that appearing in the CO2.The higher aliphatic alcohols suppress total CO2formation during rat liver slice respiration much more than does ethanol at equivalent concentrations.

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