scholarly journals Activity Coefficients for Liquid Organic Reactions: Towards a Better Understanding of True Kinetics with the Synthesis of Jasmin Aldehyde as Showcase

2019 ◽  
Vol 20 (15) ◽  
pp. 3819 ◽  
Author(s):  
Philippe M. Heynderickx
Keyword(s):  
Liquid Phase ◽  
Activity Coefficients ◽  
Aldol Condensation ◽  
Product Distribution ◽  
Organic Reactions ◽  
Parameter Estimates ◽  
Yield Values ◽  
Average Activity ◽  
Pronounced Deviation ◽  
Acceptable Parameter

The aldol condensation of benzaldehyde and heptanal is taken as an example of reversible liquid phase organic reactions to show that inclusion of activity coefficients reveal distinct differences in conversion and product distribution when different solvents methanol, ethanol, n-propanol, or n-butanol are used. The purpose of this work is to show a pronounced solvent effect for a given set of identical kinetic parameters, i.e., the same liquid phase kinetics can result in different conversion and yield values, depending on the choice of solvent. It was shown that subsequent parameter estimation without inclusion of the activity coefficients resulted in a pronounced deviation from the ‘true’ kinetics, up to a factor of 30. It is proposed that the usage of average activity coefficients gives already a significant improvement, resulting in acceptable parameter estimates.

Esterification of 1,4-dichlorobutane with sodium formate under solid–liquid phase transfer catalysis. A kinetic study

1989 ◽  
Vol 67 (2) ◽  
pp. 245-249 ◽  
Author(s):  
Hayder A. Zahalka ◽  
Yoel Sasson
Keyword(s):  
Liquid Phase ◽  
Kinetic Study ◽  
Quaternary Ammonium ◽  
Phase Transfer Catalysis ◽  
Phase Transfer ◽  
Sodium Formate ◽  
Product Distribution ◽  
Quaternary Ammonium Salts ◽  
Ammonium Salts ◽  
Solid Liquid

Kinetic data are reported regarding the esterification of 1,4-dichlorobutane with sodium formate catalyzed by quaternary ammonium salts as a model for reactions in series, under solid–liquid phase transfer conditions. The process was found to follow a consecutive first-order mechanism of the general type A → R → S. The reactivity of the quaternary ammonium salts with regard to the counteranion was Cl− > Br− > 1− > HSO4−. The reaction rate was linearly dependent on catalyst concentration up to 12 mol% of catalyst relative to the substrate. Above this concentration the rate was constant and independent of the amount of the catalyst. The activation energy of the two consecutive steps was found to be similar (21 kcal/mol). Therefore, the product distribution (R/S) is not appreciably affected by temperature. A mechanism termed "Thin aqueous boundary layer" is suggested for nucleophilic displacement reactions under solid–liquid phase transfer conditions. Keywords: phase transfer catalysis, series reactions, kinetic study.

Isobaric vapour-liquid equilibrium data of the 1,2-dichloroethane-water system at 101.3 kPa

1989 ◽  
Vol 54 (11) ◽  
pp. 2848-2855 ◽  
Author(s):  
Daniel Bobok ◽  
Elemír Kossaczký ◽  
Július Surový
Keyword(s):  
Liquid Phase ◽  
Activity Coefficients ◽  
Water System ◽  
Vapour Phase ◽  
Solubility Data ◽  
Liquid Equilibrium ◽  
Equilibrium Data ◽  
Van Laar Equation

Isobaric vapour-liquid equilibrium data for the 1,2-dichloroethane-water system were calculated on the assumption of ideal behaviour of the vapour phase on using the van Laar equation for activity coefficients of the components in the liquid phase. The parameters of the van Laar equation were calculated from the solubility of 1,2-dichloroethane in water and of water in 1,2-dichloroethane determined experimentally in this work. On using the solubility data, the parameters of the heteroazeotropic point at the pressure of 101.3 kPa were also calculated.

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