Servizio Comunitario di Informazione in materia di Ricerca e Sviluppo - CORDIS

Kinetics and mechanisms of catalytic chemical reactions in solution

The study concerns reactions yielding various organic compounds and polymeric materials. This involves investigations in the field of kinetics, mechanism and catalysis of nucleophilic addition and substitution reactions in which reagents able to form autoassociates and/or heteroassociates are taking part. These molecular organizations lead to specific kinetic pecularities, which result from processes evolving through different parallel routes, which, in turn, are dependent on the content variations of the reacting species in solution. The concept of optimal pre-reaction complexes of microreactors lying on the reaction path is being developed, involving the idea that the reaction characteristics are directly connected to the molecular structure of liquids. To determine the way these microstructural factors act on the properties of such reaction systems, the study compares the kinetic behaviour of these systems in various solution media and investigate the formation of associations and complexes involving the reactive species.

Model reactions of isocyanates with alcohols and activated esters with amines have been investigated. Organotin compounds, carboxylic acids, tertiary amines were used as a catalysts. Some of these catalysts were immobilized on a polymer carrier. Influence of heterogenization of soluble polymer supported catalysts on their catalytic activity in urethane formation have been studied. The activating role of auto-solvation of pre-reaction complex by polymer chain of COOH-group containing catalyst in esters aminolysis reaction is estimated. The catalytic assistance of alcohol in aminolysis of esters in solution is found as result of alcohol participation in the stage of proton transfer from amine nitrogen atom to ester molecule. The reaction urethane formation in solution was studied too under the action of ultrasound and absent of the effect irradiation is estimated.

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Université de Mons-Hainaut
Avenue Maistriau 19
7000 Mons
Belgium
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