Activité estérolytique de 5(6)-N-Alkyl-2-Benzimidazolemethanethiols en présence de micelles cationiques, influence de l'hydrophobicité des réactifs, évolution du système au cours du temps

Abstract : A general synthetic approach of 3,4-diaminophenylalcanes is decribed with their transformation into a2-benzimidazolemethanethiols series substitued in 5(6) position by an aliphatic chain containing 1 to 12 carbon atoms. The esterolytic activity of these new heterocyclic thiols towards hydrophobic p-nitrophenylalkanoates has been studied in the presence of cationic micelles (CTABr, STACI). Kinetic results evidence a dual behavior according to the state of ageing of the micellar medium : with a freshly prepared solution the kinetic process is fast while it becomes slow for a ready-to-use store solution. This duration increases with the thiol and surfactant alkyl chain lengh. The determination of the specific activity of the present nucleophilic species (pH dependence, modelling approach, optimized calculation) shows that the rapid process, at neutral pH, is the result of a cooperative effect of the non-ionic from the benzimidazolethiol. Moreover, a very strong acceleration is observed in that case with reference to a hydro-alcoholic medium. For the slow process, this effect is inhibited by a micellar aggregation
Document type :
Theses
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http://docnum.univ-lorraine.fr/prive/INPL_T_1991_KRATI_N.pdf
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https://hal.univ-lorraine.fr/tel-01752135
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Submitted on : Thursday, March 29, 2018 - 1:33:02 PM
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  • HAL Id : tel-01752135, version 1

Citation

Noureddine Krati. Activité estérolytique de 5(6)-N-Alkyl-2-Benzimidazolemethanethiols en présence de micelles cationiques, influence de l'hydrophobicité des réactifs, évolution du système au cours du temps. Autre. Institut National Polytechnique de Lorraine, 1991. Français. ⟨NNT : 1991INPL121N⟩. ⟨tel-01752135⟩

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