ChemInform Abstract: KINETICS OF FORMATION OF ELECTRONICALLY EXCITED CHLORINE, BROMINE CHLORIDE AND BROMINE IN THE RECOMBINATION OF GROUND-STATE HALOGEN ATOMS

A detailed study of the kinetics of the raction H + NO + M = HNO + M + 49.9 kcal/mole (1) shows that all the third bodies examined except H 2 O give similar relative efficiencies for the formation of ground state ( 1 A ') and electronically excited ( 1 A ") HNO. The overall rate constants found at 293°K (in cm 6 mole -2 s -1 x 10 -16 ) are: Ar, 1.11 ± 0.15; H 2 , 2.07 ± 0.18; CO 2 , 2.26 ± 0.23; N 2 O, 2⋅45 ± 0⋅44; SF 6 , 3.96 ± 0.46; H 2 O, 6.8 ± 1.2. For the reaction D + NO + Ar = DNO + Ar a rate constant of (1.28 ± 0.21) x 10 16 cm 6 mole -2 s -1 was obtained. The relative third body efficiencies in reaction (1) were less similar to the closely related Process H + O 2 + M = HO 2 + M + 47.1 kcal/mole than to the reaction O + NO + M = NO 2 + M + 73.2 kcal/mole.

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Reactions of diatomic molecules. IV. Kinetics of formation of bromine chloride

The Journal of Physical Chemistry ◽

10.1021/j100865a073 ◽

1967 ◽

Vol 71 (6) ◽

pp. 1952-1953 ◽

Cited By ~ 7

Author(s):

Peter R. Walton ◽

Richard M. Noyes

Keyword(s):

Diatomic Molecules ◽

Bromine Chloride ◽

Kinetics Of Formation ◽

Kinetics Of

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Recombination of ground state halogen atoms. Part 4.—Kinetics of recombination of bromine atoms

Journal of the Chemical Society Faraday Transactions 2 Molecular and Chemical Physics ◽

10.1039/f29736900412 ◽

1973 ◽

Vol 69 (0) ◽

pp. 412-418 ◽

Cited By ~ 6

Author(s):

Michael A. A. Clyne ◽

A. R. Woon-Fat

Keyword(s):

Ground State ◽

Halogen Atoms ◽

Kinetics Of

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Kinetics of cyclization of S-ethoxycarbonylmethylisothiouronium chloride to 2-imino-4-thiazolidone

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19790912 ◽

1979 ◽

Vol 44 (3) ◽

pp. 912-917 ◽

Cited By ~ 1

Author(s):

Vladimír Macháček ◽

Said A. El-bahai ◽

Vojeslav Štěrba

Keyword(s):

Hydrochloric Acid ◽

Dilute Hydrochloric Acid ◽

Base Catalysis ◽

General Base ◽

Rate Limiting Step ◽

Limiting Step ◽

Kinetics Of Formation ◽

Acid Catalyzed ◽

Rate Limiting ◽

Kinetics Of

Kinetics of formation of 2-imino-4-thiazolidone from S-ethoxycarbonylmethylisothiouronium chloride has been studied in aqueous buffers and dilute hydrochloric acid. The reaction is subject to general base catalysis, the β value being 0.65. Its rate limiting step consists in acid-catalyzed splitting off of ethoxide ion from dipolar tetrahedral intermediate. At pH < 2 formation of this intermediate becomes rate-limiting; rate constant of its formation is 2 . 104 s-1.

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Cyclization and acid-catalyzed hydrolysis of O-benzoylbenzamidoximes

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19862786 ◽

1986 ◽

Vol 51 (12) ◽

pp. 2786-2797

Author(s):

František Grambal ◽

Jan Lasovský

Keyword(s):

Reaction Rate ◽

Kinetic Isotope ◽

Acid Base Equilibrium ◽

Mineral Acids ◽

Kinetics Of Formation ◽

Acid Catalyzed ◽

Ph Scale ◽

Kinetics Of ◽

Hydrolysis Of ◽

Derivatives Of

Kinetics of formation of 1,2,4-oxadiazoles from 24 substitution derivatives of O-benzoylbenzamidoxime have been studied in sulphuric acid and aqueous ethanol media. It has been found that this medium requires introduction of the Hammett H0 function instead of the pH scale beginning as low as from 0.1% solutions of mineral acids. Effects of the acid concentration, ionic strength, and temperature on the reaction rate and on the kinetic isotope effect have been followed. From these dependences and from polar effects of substituents it was concluded that along with the cyclization to 1,2,4-oxadiazoles there proceeds hydrolysis to benzamidoxime and benzoic acid. The reaction is thermodynamically controlled by the acid-base equilibrium of the O-benzylated benzamidoximes.

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Fluorescence Quenching of Aminodiphenylamines with Chloromethanes

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc20021154 ◽

2002 ◽

Vol 67 (8) ◽

pp. 1154-1164 ◽

Cited By ~ 2

Author(s):

Nachiappan Radha ◽

Meenakshisundaram Swaminathan

Keyword(s):

Charge Transfer ◽

Fluorescence Quenching ◽

Ground State ◽

Rate Constants ◽

Quenching Mechanism ◽

Quenching Rate ◽

Charge Transfer Interaction ◽

Electronically Excited ◽

A Charge

The fluorescence quenching of 2-aminodiphenylamine (2ADPA), 4-aminodiphenylamine (4ADPA) and 4,4'-diaminodiphenylamine (DADPA) with tetrachloromethane, chloroform and dichloromethane have been studied in hexane, dioxane, acetonitrile and methanol as solvents. The quenching rate constants for the process have also been obtained by measuring the lifetimes of the fluorophores. The quenching was found to be dynamic in all cases. For 2ADPA and 4ADPA, the quenching rate constants of CCl4 and CHCl3 depend on the viscosity, whereas in the case of CH2Cl2, kq depends on polarity. The quenching rate constants for DADPA with CCl4 are viscosity-dependent but the quenching with CHCl3 and CH2Cl2 depends on the polarity of the solvents. From the results, the quenching mechanism is explained by the formation of a non-emissive complex involving a charge-transfer interaction between the electronically excited fluorophores and ground-state chloromethanes.

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