The kinetics of nucleophilic aromatic substitution of three nitrothiophene derivatives in different[1-butyl-3-methylimidazolium][N3]/ionic liquid binary mixtures was studied spectrophotometricallyat 298 K. Ionic liquids differing for cation structure (imidazolium or pyrrolidinium) and for size,shape, and coordination ability of the anion ([BF4-], [PF6-], [SbF6-], and [NTf2-]) were used.Furthermore, in order to have a comparison with conventional organic solvents, the target reactionwas also carried out in DMF solution at increasing concentration of NaN3 or [bmim][N3]. Datacollected show that the reaction occurs faster inDMFthan in ionic liquid solution. Furthermore, as aconsequence of the ability of all solvent media to favor the leaving group departure, a simple lineardependence of the pseudo-first-order kinetic constant from nucleophile concentration was detected.The results of this kinetic investigation once more underline that ionic liquids are able to exertpeculiar effects that can be understood also considering their three-dimensional organization.
|Numero di pagine||5|
|Rivista||Journal of Organic Chemistry|
|Stato di pubblicazione||Published - 2010|
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