Kinetics and Mechanism of the Sulfonation of 2-Phenyl-1-ethanesulfonic acid

1973 ◽  
Vol 51 (3) ◽  
pp. 462-465 ◽  
Author(s):  
A. Koeberg-Telder (Mrs.) ◽  
Z. R. H. Nienhuis (Mrs.) ◽  
H. Cerfontain
Keyword(s):  
Sulfonic Acid ◽  
Kinetics And Mechanism ◽  
Partial Rate ◽  
Ethanesulfonic Acid ◽  
Kinetics Of ◽  
Sulfonate Anion

The kinetics of the sulfonation of 2-phenyl-1-ethanesulfonic acid in 85.0–98.4% H2SO4 has been studied. The results are discussed in terms of sulfonation of the unionized sulfonic acid and its conjugated base, the sulfonate anion. Partial rate factors for the —CH2CH2SO3H substituent are reported.

Kinetics and mechanism of the reaction of iron(III) with 6-methyl-2,4-heptanedione and 3,5-heptanedione

1990 ◽  
Vol 55 (8) ◽  
pp. 1984-1990 ◽  
Author(s):  
José M. Hernando ◽  
Olimpio Montero ◽  
Carlos Blanco
Keyword(s):  
Aqueous Solution ◽  
Metal Ion ◽  
Activation Parameters ◽  
Enol Form ◽  
Kinetics And Mechanism ◽  
Kinetic Constants ◽  
Steric Factors ◽  
Kinetics Of ◽  
Mechanism Of The Reaction

The kinetics of the reactions of iron(III) with 6-methyl-2,4-heptanedione and 3,5-heptanedione to form the corresponding monocomplexes have been studied spectrophotometrically in the range 5 °C to 16 °C at I 25 mol l-1 in aqueous solution. In the proposed mechanism for the two complexes, the enol form reacts with the metal ion by parallel acid-independent and inverse-acid paths. The kinetic constants for both pathways have been calculated at five temperatures. Activation parameters have also been calculated. The results are consistent with an associative activation for Fe(H2O)63+ and dissociative activation for Fe(H2O)5(OH)2+. The differences in the results for the complexes of heptanediones studied are interpreted in terms of steric factors.

Degradation kinetics of 4-amino naphthalene-1-sulfonic acid by a biofilm-forming bacterial consortium under carbon and nitrogen limitations

2012 ◽  
Vol 39 (8) ◽  
pp. 1169-1177 ◽  
Author(s):  
C. Juárez-Ramírez ◽  
R. Velázquez-García ◽  
N. Ruiz-Ordaz ◽  
J. Galíndez-Mayer ◽  
O. Ramos Monroy
Keyword(s):  
Sulfonic Acid ◽  
Degradation Kinetics ◽  
Bacterial Consortium ◽  
Carbon And Nitrogen ◽  
Kinetics Of

Derivatives of isatin in aqueous solution. I. Kinetics of ring opening of Isatin-5-sulfonate

1981 ◽  
Vol 34 (2) ◽  
pp. 365 ◽  
Author(s):  
H Stunzi
Keyword(s):  
Ring Opening ◽  
Rate Of Change ◽  
Spectroscopic Methods ◽  
Ph Values ◽  
Buffer Region ◽  
Pka Value ◽  
Back Titration ◽  
Kinetics Of ◽  
Derivatives Of ◽  
Sulfonate Anion

The reactions of isatin-5-sulfonate anion (si-) which cause a hysteresis in pH titrations were studied by pH-metric and n.m.r, spectroscopic methods. Rapid alkalimetric titrations [I 0.15 M (KNO3),37�] gave the pKa value corresponding to the addition of OH- to si- [pKa(ring) 9.55]. The slow ring opening to the sulfonatoisatate dianion (sia2-) led to a drift of the pH values towards an equilibrium buffer region. Its pKa, value [pKa(eq) 3.44] corresponds to the reaction si-+H2O ↔ sia 2-+H+ Rapid back-titration gave the pKa value of the ring-opened species Hsia- [pKa(open) c. 1.3]. The rate law for the ring opening d[sia]/dt=k2 [siOH](OH)+k1*[si] was obtained from the rate of change of pH. N-Methylisatin-5-sulfonate behaves analogously.

Reactions of the radical cation derived from 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS·+) with amino acids. Kinetics and mechanism

2000 ◽  
Vol 78 (8) ◽  
pp. 1052-1059 ◽  
Author(s):  
C Aliaga ◽  
E A Lissi
Keyword(s):  
Amino Acids ◽  
Radical Cation ◽  
Sulfonic Acid ◽  
Biological Fluids ◽  
Reaction Rates ◽  
Kinetics And Mechanism ◽  
Specific Rate ◽  
Wide Range ◽  
Initial Ph ◽  
Secondary Reactions

Stable free radicals derived from 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS·+) have been extensively employed to monitor the antioxidant capacity of biological fluids and beverages. Besides reacting with typical antioxidants (such as phenols or thiols) these radicals react with a variety of hydrogen or electron donors. The present work reports on the kinetics and mechanism of these radical reactions with several amino acids. Reaction rates notably increase when the pH of the media increases and, when measured under similar conditions, follows the ordercysteine > > tryptophan > tyrosine > histidine > cystineThe kinetics of the process is interpreted in terms of a mechanism comprising an initial pH dependent reversible step, followed by secondary reactions of the substrate derived radical with itself or with another ABTS·+; this simple three-step mechanism leads to very complex kinetic expressions. The specific rate constants of several of the elementary steps were determined by working under a wide range of substrate, radical, and ABTS concentrations. The values obtained for the initial interaction between the ABTS derived radical and the substrate range from 0.5 M–1 s–1 to 1.9 × 106 M–1 s–1 for histidine and cysteine, respectively.Key words: ABTS radical cation, 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid), amino acids, kinetics.

scholarly journals Non-isothermal TGA study on the combustion reaction kinetics and mechanism of low-rank coal char

RSC Advances ◽  
2018 ◽  
Vol 8 (41) ◽  
pp. 22909-22916 ◽  
Author(s):  
Yingjie Hu ◽  
Zhiqiang Wang ◽  
Xingxing Cheng ◽  
Chunyuan Ma
Keyword(s):  
Thermal Analysis ◽  
Reaction Kinetics ◽  
Coal Char ◽  
Kinetics And Mechanism ◽  
Combustion Reaction ◽  
Low Rank ◽  
Low Rank Coal ◽  
Pyrolytic Char ◽  
Kinetics Of

The combustion reaction kinetics of pyrolytic char of low-rank coal was investigated by using thermal analysis technology.

Kinetics of the sorption of erythromycin by macroreticular sulfonic acid resins

1976 ◽  
Vol 10 (9) ◽  
pp. 1217-1221
Author(s):  
S. F. Klikh ◽  
G. �. El'kin ◽  
G. V. Samsonov
Keyword(s):  
Sulfonic Acid ◽  
Kinetics Of
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