Reaction rate of crosslinkings by using a metallated polymer. III. Solvent effects on rate constants of grafting and intramolecular crosslinking reactions.

1982 ◽  
Vol 20 (11) ◽  
pp. 3199-3205 ◽  
Author(s):  
Koji Ishizu ◽  
Atsushi Ohtaka ◽  
Takashi Fukutomi ◽  
Toshio Kakurai
Keyword(s):  
Solvent Effects ◽  
Rate Constants ◽  
Reaction Rate ◽  
Crosslinking Reactions

Solvent Effects on the Kinetics and Mechanism of the Acid-Catalysed Hydrolysis of Diterf.-butylsuccinate in Dioxane-Water Mixtures

1985 ◽  
Vol 40 (1) ◽  
pp. 84-91 ◽  
Author(s):  
Adel N. Asaad ◽  
Fayez Y. Khalil
Keyword(s):  
Dielectric Constant ◽  
Solvent Effects ◽  
Rate Constants ◽  
Mixed Type ◽  
Reaction Rate ◽  
Solvent Composition ◽  
Water Molecules ◽  
Molecular Dipole ◽  
First Order ◽  
Hydrolysis Of

The acid-catalysed hydrolysis of ditert.-butylsuccinate in dioxane-water mixtures proceeds via consecutive first-order reactions. The rate constants kI and kII corresponding to the two steps decrease with increasing dioxane content of the medium. After reaching a minimum at 90% (w/w) dioxane, both rate constants increase again with further addition of dioxane. The kinetic ratio kI/kII is smaller than the statistical value 2.0, and is markedly affected both by solvent composition and temperature. The maximum concentration of the intermediate half ester decreases with increasing dioxane content. The observed activation energies EI and EII of the two steps of the reaction are largely dependent on temperature as well as solvent composition indicating a mixed type of bond fission represented by the AAl 1 and AAC 2 mechanisms, whose relative contributions in the overall rate constants kI and kIIcould be calculated on the basis of the number of water molecules incorporated in the corresponding transition states. The effect of bulk dielectric constant on the reaction rate was investigated in the light of the available electrostatic theories and showed the reaction to be an ion-molecular dipole type of interaction. The activation thermodynamic parameters were computed and discussed as criteria of solvent effect and mechanism.

scholarly journals Investigation of the reactivity of 4-pyrimidinecarboxylic, 6-hydroxy-4-pyrimidinecarboxylic and 5-hydroxyorotic acids with diazodiphenylmethane in various alcohols: Part III

2007 ◽  
Vol 72 (3) ◽  
pp. 205-214 ◽  
Author(s):  
Fathi Assaleh ◽  
Aleksandar Marinkovic ◽  
Sasa Drmanic ◽  
Bratislav Jovanovic
Keyword(s):  
Solvent Effects ◽  
Spectrophotometric Method ◽  
Rate Constants ◽  
Alkyl Group ◽  
Relative Permittivity ◽  
Reaction Rate ◽  
Hydrogen Atoms ◽  
Protic Solvents ◽  
Hydroxybenzoic Acids ◽  
Polar Constant

Rate constants for the reaction of diazodiphenylmethane (DDM) with 4-pyrimidinecarboxylic, 6-hydroxy-4-pyrimidinecarboxylic and 5-hydroxyorotic acids were determined in twelve protic solvents at 30 ?C using the well known UV-spectrophotometric method. The second order rate contants for the examined acids were correlated using the appropriate solvent parameters by the equation log k = log k0 + af(e) + bs * + cngH were f(e) is the Kirkwood function of relative permittivity [(e-l)/(2e + 1 )], s * is the Taft polar constant for the alkyl group R in the alcohol ROH, and nyH is themumber of hydrogen atoms in the (-position in the alcohol. The results obtained for the investigated acids were compared with the corresponding results for benzoic, 2- and 3-hydroxybenzoic acids and the influence of the structure of the investigated acids on the reactivity in hydroxylic solvents is discussed. It was also possible to evaluate and distinguish the specific and non-specific solvent effects and their influence on the reaction rate.

Measurement of the OH Reaction Rate Constants for CF3CH2OH, CF3CF2CH2OH, and CF3CH(OH)CF3

1999 ◽  
Vol 103 (15) ◽  
pp. 2664-2672 ◽  
Author(s):  
Kazuaki Tokuhashi ◽  
Hidekazu Nagai ◽  
Akifumi Takahashi ◽  
Masahiro Kaise ◽  
Shigeo Kondo ◽  
...  
Keyword(s):  
Rate Constants ◽  
Reaction Rate ◽  
Reaction Rate Constants

scholarly journals PREDICTION OF REACTION RATE CONSTANTS OF HYDROXYL RADICAL WITH ORGANIC COMPOUNDS

2014 ◽  
Vol 59 (1) ◽  
pp. 2252-2259 ◽  
Author(s):  
ZHEN CHEN ◽  
XINLIANG YU ◽  
XIANWEI HUANG ◽  
SHIHUA ZHANG
Keyword(s):  
Hydroxyl Radical ◽  
Organic Compounds ◽  
Rate Constants ◽  
Reaction Rate ◽  
Reaction Rate Constants
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