Kinetics of the base-catalyzed bromination of nitroacetone

1962 ◽  
Vol 270 (1342) ◽  
pp. 411-416 ◽  
Keyword(s):  
Zero Order ◽  
Aqueous Buffer ◽  
Buffer Solutions ◽  
Carboxylate Anions ◽  
Kinetics Of ◽  
Catalytic Effects

The kinetics of the bromination of nitroacetone at 0 °C have been studied in aqueous buffer solutions, the disappearance of bromine being followed by measuring the redoxpotential. The reaction is of zero order with respect to bromine and exhibits general catalysis by bases, so that the observed rate is that of the ionization of the ketone. The catalytic effects of five carboxylate anions are closely related to the basic strengths of the catalysts. The results are discussed in relation to the behaviour of analogous substances.

Kinetics of the base-catalyzed bromination of ethyl nitroacetate

1959 ◽  
Vol 251 (1264) ◽  
pp. 41-45 ◽  
Keyword(s):  
Zero Order ◽  
Aqueous Buffer ◽  
First Order ◽  
Keto Esters ◽  
Buffer Solutions ◽  
Pyridine Bases ◽  
Carboxylate Anions ◽  
Ethyl Nitroacetate ◽  
Kinetics Of ◽  
Catalytic Effects

The kinetics of the bromination of ethyl nitroacetate have been studied in aqueous buffer solutions. The reaction is of the first order with respect to the ester, and of zero order with respect to bromine; it exhibits general catalysis by bases. The catalytic effects of six carboxylate anions and two pyridine bases are closely related to their basic strengths, but in other respects the reaction does not conform to the regularities previously found for the rates of ionization of ketones and keto-esters.

Kinetics of the base-catalyzed bromination of s -dichloroacetone

1960 ◽  
Vol 255 (1281) ◽  
pp. 214-217 ◽  
Keyword(s):  
Aqueous Solution ◽  
Carbonyl Group ◽  
Zero Order ◽  
Degree Of Hydration ◽  
Aqueous Buffer ◽  
Buffer Solutions ◽  
Polar Groups ◽  
Carboxylate Anions ◽  
Kinetics Of ◽  
Catalytic Effects

The kinetics of the bromination of s -dichloroacetone have been studied in aqueous buffer solutions. The reaction is of zero order with respect to bromine and exhibits general catalysis by bases, so that the observed rate is that of the ionization of the ketone. The catalytic effects of four carboxylate anions and of water are closely related to the basic strengths of the catalysts. In relating rates of ionization to the structures of substituted ketones it is neces­sary to correct the observed rates for the degree of hydration of the carbonyl group in aqueous solution. The corrected rates for acetone and its chloro-derivates are discussed in terms of the polar groups which they contain.

Kinetics of the base-catalyzed halogenation of 2-carbetboxycyclobexanone

1952 ◽  
Vol 210 (1102) ◽  
pp. 322-326 ◽  
Keyword(s):  
Carboxylic Acids ◽  
Opposite Direction ◽  
Zero Order ◽  
Water Molecules ◽  
Ring Strain ◽  
Aqueous Buffer ◽  
First Order ◽  
Buffer Solutions ◽  
Carboxylate Anions ◽  
Kinetics Of

The kinetics of iodination of 2-carbethoxycyclohexanone have been studied colorimetrically in aqueous buffer solutions. The reaction is of the first order with respect to the ester, of zero order with respect to iodine, and is catalyzed by water molecules and by the anions of carboxylic acids. The catalytic constants of four carboxylate anions obey a relation of the Bronsted type, the exponent of which conforms to regularities previously established for a series of ketones and esters. Under comparable conditions 2-carbethoxycyclohexanone is halogenated 100 to 400 times more slowly than is 2-carbethoxycyclopentanone. This difference is in the opposite direction to that anticipated on the basis of ring strain, though it is paralleled by some other observations on 5- and 6-membered rings.

scholarly journals Kinetics of the base-catalyzed bromination of ethyl cyclopentanone 2 -carboxylate

1948 ◽  
Vol 192 (1031) ◽  
pp. 479-489 ◽  
Keyword(s):  
Aqueous Solution ◽  
Acid Catalysis ◽  
Bromine Atom ◽  
Acid Solutions ◽  
Buffer Solutions ◽  
Hydrochloric Acid Solutions ◽  
Carboxylate Anions ◽  
Basic Catalysts ◽  
Bromine Concentration ◽  
Kinetics Of

The kinetics of the bromination of ethyl cyclopentanone 2-carboxylate in the presence o f a number of basic catalysts have been investigated in aqueous solution at 25° C. Under the conditions chosen the bromination proceeds to completion and its rate is independent o f the bromine concentration, being determined by the rate of transfer of a proton to the catalyzing species. Since only one bromine atom is introduced, the kinetics are free from com plications due to successive stages. N o detectable acid catalysis occurs. Values o f the catalytic constants o f seven basic species have been determined from measurements in buffer solutions and in hydrochloric acid solutions. The relation between the catalytic constants o f the four carboxylate anions studied is accurately expressed by an equation of the form due to Bronsted. The ion H 2 P0 4 does not obey this equation. In its general kinetic behaviour the bromination of ethylcyclopentanone 2-carboxylate is found to conform to the regularities previously shown in the ionization of related substrates.

Kinetics of the iodination of ethyl pyruvate

1967 ◽  
Vol 298 (1453) ◽  
pp. 178-183 ◽  
Keyword(s):  
Aqueous Solution ◽  
Complex Formation ◽  
Equilibrium Constant ◽  
Pyruvic Acid ◽  
Ethyl Pyruvate ◽  
Acid Strength ◽  
Zero Order ◽  
Carboxylate Anions ◽  
Iodination Reaction ◽  
Kinetics Of

The iodination of ethyl pyruvate in aqueous solution is kinetically of zero order with respect to iodine and is catalysed by bases: the observed rate is therefore the rate of ionization of the ester. The rate of ionization in the absence of catalysts other than water is approxi­mately the same as that found previously for pyruvic acid, which weakens the evidence for intramolecular catalysis in the ionization of the latter substance. Basic catalysis by carboxylate anions in the iodination of ethyl pyruvate obeys the Brönsted relation, but the value of the exponent β does not fall into line with values previously found for monoketones or β -diketones. No complex formation is detectable between iodine and ethyl pyruvate. The iodination reaction does not go to completion, and its equilibrium constant was measured. Values for the acid strength of ethyl pyruvate estimated from this equilibrium constant and from the rate of ionization are p K = 16.6 and p K = 15.4 respectively.

Kinetics of catalytic reduction of nitrogen oxide by carbon monoxide on CuO/Al2O3 catalyst

1983 ◽  
Vol 48 (11) ◽  
pp. 3202-3208 ◽  
Author(s):  
Zdeněk Musil ◽  
Vladimír Pour
Keyword(s):  
Carbon Monoxide ◽  
Nitrogen Oxide ◽  
Rate Equation ◽  
Catalytic Reduction ◽  
Zero Order ◽  
Spectroscopic Measurements ◽  
First Order ◽  
Ir Spectroscopic ◽  
Kinetics Of ◽  
Al2o3 Catalyst

The kinetics of the reduction of nitrogen oxide by carbon monoxide on CuO/Al2O3 catalyst (8.36 mass % CuO) were determined at temperatures between 413 and 473 K. The reaction was found to be first order in NO and zero order in CO. The observed kinetics are consistent with a rate equation derived from a mechanism proposed on the basis of IR spectroscopic measurements.

Micellar Catalytic Effects on the Kinetics of the Ionization of Basic Amino Acid and Acidic Amino Acid Studied by the Ultrasonic Absorption Method

Langmuir ◽  
1995 ◽  
Vol 11 (5) ◽  
pp. 1477-1481
Author(s):  
Teruyo Yamashita ◽  
Miyuki Yamasaki ◽  
Takayuki Sano ◽  
Shoji Harada ◽  
Hiroshige Yano
Keyword(s):  
Amino Acid ◽  
Basic Amino Acid ◽  
Ultrasonic Absorption ◽  
Absorption Method ◽  
Acidic Amino Acid ◽  
Kinetics Of ◽  
Catalytic Effects

Supercritical Fluid Deposition of Ruthenium Thin Films: A Kinetic Study

2007 ◽  
Vol 992 ◽  
Author(s):  
Christos F. Karanikas ◽  
James J. Watkins
Keyword(s):  
Thin Films ◽  
Growth Rate ◽  
Deposition Temperature ◽  
Zero Order ◽  
Measurable Effect ◽  
Deposition Rates ◽  
Reaction Pressure ◽  
Deposition Kinetics ◽  
First Order ◽  
Kinetics Of

AbstractThe kinetics of the deposition of ruthenium thin films from the hydrogen assisted reduction of bis(2,2,6,6-tetramethyl-3,5-heptanedionato)(1,5-cyclooctadiene)ruthenium(II), [Ru(tmhd)2cod], in supercritical carbon dioxide was studied in order to develop a rate expression for the growth rate as well as to determine a mechanism for the process. The deposition temperature was varied from 240°C to 280°C and the apparent activation energy was 45.3 kJ/mol. Deposition rates up to 30 nm/min were attained. The deposition rate dependence on precursor concentrations between 0 and 0.2 wt. % was studied at 260°C with excess hydrogen and revealed first order deposition kinetics with respect to precursor at concentrations lower then 0.06 wt. % and zero order dependence at concentrations above 0.06 wt. %. The effect of reaction pressure on the growth rate was studied at a constant reaction temperature of 260°C and pressures between 159 bar to 200 bar and found to have no measurable effect on the growth rate.

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