Photooxidation of methyl ethyl ketone vapor

The photochemical reaction between methyl ethyl ketone and oxygen has been studied at 150 °C with light of 3 130 Å. Measurement of the quantum yields of the major products of the reaction indicates the chain nature of the reaction, the length of the chain decreasing with increase in time. Extrapolation of quantum yields of products to zero time allows the evaluation of several relative rate constants and at least an indication of the individual radical sources of the observed products. It is shown that abstraction of hydrogen atoms from the methyl group takes place at least at a quarter the rate of abstraction of a secondary hydrogen from the ethyl group at 150 °C. In the initial products the ethyl group gives mainly acetaldehyde or perpropionic acid, the methyl group gives formaldehyde and methanol, and the carbonyl group gives carbon dioxide and perpropionic acid with a little carbon monoxide.

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The addition of methyl radicals to ethylene, propylene, the butenes and higher 1-olefines

Proceedings of the Royal Society of London Series A - Mathematical and Physical Sciences ◽

10.1098/rspa.1957.0094 ◽

1957 ◽

Vol 240 (1222) ◽

pp. 396-407 ◽

Cited By ~ 15

Keyword(s):

Double Bond ◽

Carbon Atom ◽

Rate Constants ◽

Relative Rate ◽

Methyl Radicals ◽

Active Hydrogen ◽

Hydrogen Atoms ◽

Methyl Group ◽

Ethylene Propylene ◽

Relative Rate Constants

The addition of methyl radicals to ethylene and its homologues in iso -octane solution was studied over the temperature range 55 to 85°C. The relative rate constants of addition to ethylene, propylene and iso -butene determined at 65°C are 34, 22 and 36 respectively. Taking into account the statistical factor of 2 for ethylene, we conclude that the increasing ease of addition for this series of olefines reflects the increasing stability of the produced radicals. The rates of addition to trans - and cis -butene-2 are significantly lower (6.9 and 3.4 respectively), indicating a steric hindrance resulting from the presence of a methyl group on the carbon atom on which the reaction takes place. Identical rates of addition were found for propylene, butene-1,pentene-1, 3 methyl butene-1, heptene-1, decene-1 and hexadecene-1, indicating that the rates of addition are not affected by the length and the shape of the hydrocarbon ‘tail’. The rates of abstraction of hydrogen atoms by methyl radicals were determined. It was found that the rate constants for active hydrogen ( α to C=C double bond) fall into three distinctive classes characterizing the primary, the secondary, and the tertiary hydrogen atoms.

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Arrhenius-Parameter und kinetischer Isotopeneffekt für die Reaktion von Wasserstoffatomen mit Silan

Zeitschrift für Naturforschung A ◽

10.1515/zna-1974-0320 ◽

1974 ◽

Vol 29 (3) ◽

pp. 493-496 ◽

Cited By ~ 9

Author(s):

Peter Potzinger ◽

Louis C. Glasgow ◽

Bruno Reimann

Keyword(s):

Kinetic Isotope Effect ◽

Relative Rate ◽

Isotope Effects ◽

Preexponential Factor ◽

Kinetic Isotope Effects ◽

Hydrogen Atoms ◽

Kinetic Isotope ◽

Abstraction Reaction ◽

Upper Limits ◽

Relative Rate Constants

The Reaction of Hydrogen Atoms with Silane; Arrhenius Parameters and Kinetic Isotope Effect Relative rate constants were measured for the systems H + C2H4/SiD4 and D + C2D4/SiH4 over a wide temperature range. From the known arrheniusparameter for the reaction H + C2H4 the activation energy EA and the preexponential factor A of the abstraction reactionH + SiD4 → HD + SiD3may be calculated. Values of EA = 3.2 kcal/Mol and A = 4.92 • 1013 cm3 Mol-1 sec-1 were obtained. Upper limits for the kinetic isotope effects are given in the paper

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Photo degradation kinetics of insensitive munitions constituents nitroguanidine, nitrotriazolone, and dinitroanisole in natural waters

10.21079/11681/41900 ◽

2021 ◽

Author(s):

Lee Moores ◽

Stacy Jones ◽

Garrett George ◽

David Henderson ◽

Timothy Schutt

Keyword(s):

Laboratory Experiments ◽

Natural Waters ◽

Matrix Effects ◽

Degradation Kinetics ◽

Relative Rate ◽

Ph Dependence ◽

Degradation Pathway ◽

Quantum Yields ◽

The Individual ◽

Kinetics Of

Herein the matrix effects on the kinetics of aqueous photolysis for the individual munitions constituents of IMX-101: nitroguanidine (NQ), dinitroanisole (DNAN), and nitrotriazolone (NTO) are reported along with the environmentally relevant kinetics and quantum yields. Photolysis potentially represents a major degradation pathway for these munitions in the environment and further understanding the complex matrices effects on photolytic kinetics was needed. Aqueous systems are of particular interest due to the high solubility of NQ (3,800 ppm) and NTO (16,642 ppm) compared to the traditional munitions trinitrotoluene (TNT, 100.5 ppm) and 1,3,5-trinitro-1,3,5-triazine (RDX, 59.9 ppm). Environmental half-lives (and quantum yields) were found to be 0.44 days, 0.83 days, and 4.4 days for NQ, DNAN, and NTO, respectively, under natural sunlight. In laboratory experiments using nominally 300 nm bulbs in a merry-go-round style reactor in DI water the relative rate of photolysis for the three munitions constituents followed the same order NQ > DNAN > NTO, where DNAN and NTO reacted 57 and 115 times more slowly, respectively, than NQ. In the various environmentally relevant matrices tested in the laboratory experiments NQ was not significantly affected, DNAN showed a faster degradation with increasing ionic strength, and NTO showed a modest salinity and pH dependence on its rate of photolysis.

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Partial methylation of methyl α-D- and β-D-threofuranoside

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19901777 ◽

1990 ◽

Vol 55 (7) ◽

pp. 1777-1782 ◽

Cited By ~ 1

Author(s):

Jiří Jarý ◽

Miroslav Marek ◽

Ivan Raich

Keyword(s):

Sodium Hydroxide ◽

Methyl Iodide ◽

Rate Constants ◽

Relative Rate ◽

Hydroxyl Groups ◽

Partial Methylation ◽

Methylation Rate ◽

Consecutive Reactions ◽

Relative Rate Constants ◽

The Individual

The methylation rate of hydroxyl groups of the title glycosides I and II has been studied in their reaction with methyl iodide and sodium hydroxide in acetonitrile. From the relative rate constants determined for the side and consecutive reactions taking place the differences in methylation rate of the individual hydroxyl groups have been deduced and are discussed from the standpoint of possible steric and polar effects.

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Photochemistry of Methyl Ethyl Ketone: Quantum Yields and S 1 /S 0 ‐Diradical Mechanism of Photodissociation

ChemPhysChem ◽

10.1002/cphc.201000522 ◽

2010 ◽

Vol 11 (18) ◽

pp. 3883-3895 ◽

Cited By ~ 18

Author(s):

Rebeka Nádasdi ◽

Gábor L. Zügner ◽

Mária Farkas ◽

Sándor Dóbé ◽

Satoshi Maeda ◽

...

Keyword(s):

Methyl Ethyl Ketone ◽

Quantum Yields ◽

Methyl Ethyl

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Selective Accessibilities of Hydroxyl Groups in the Microstructure of Cotton Cellulose

Textile Research Journal ◽

10.1177/004051756903900606 ◽

1969 ◽

Vol 39 (6) ◽

pp. 530-542 ◽

Cited By ~ 24

Author(s):

S. P. Rowland ◽

E. J. Roberts ◽

C. P. Wade

Keyword(s):

Sodium Hydroxide ◽

Rate Constants ◽

Relative Rate ◽

Heterogeneous Systems ◽

Heterogeneous Reactions ◽

Cotton Cellulose ◽

Hydroxyl Groups ◽

Relative Rate Constants ◽

The Individual ◽

Liquid Chromatographic

The reactions of 2-chloroethyldiethylamine with the hydroxyl groups at C-2, C-3, and C-6 of the d-glucopyranosyl unit of cotton cellulose were investigated as a means of evaluating the relative accessibilities of these hydroxyl groups in heterogeneous reactions of fibrous cellulose. The relative rate constants for reactions of the individual types of hydroxyl groups were determined from reactions of cellulose in solution and from reactions of disordered cellulose in heterogeneous systems. Quantitative determinations of the distributions of 2-(diethylamino)ethyl substituents in the mono-substituted d-glucopyranosyl units involved hydrolysis of the chemically modified cellulose to glucose and substituted glucoses followed by gas-liquid chromatographic analysis. The relative accessibilities of the hydroxyl groups at C-2 and C-3 vs those at C-6 were estimated for crystalline celluloses by employing the relative rate constants (noted above) together with the experimentally measured distributions of substituents resulting from heterogeneous reactions of crystalline celluloses and appropriate kinetic expressions. The relative accessibilities of the hydroxyl groups at C-2, C-3, and C-6 in cellulose in strong mercerizing media approach those of cellulose in solution. In media of lower concentration of sodium hydroxide (i.e., 4 N or 13.9%), selective accessibilities of the individual types of hydroxyl groups become evident, and these selective accessibilities become pronounced in sodium hydroxide solutions of still lower concentrations (e.g., N and 2 N).

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