Abstract:
Reaction mechanism in aromatic nucleophilic substitution reactions is discussed using kinetic study
complemented with quantum chemical calculations. The model system is the reaction of a series of
biothiols toward atrazine (ATZ) in aqueous media. The proposed reaction mechanism discloses a
non-catalyzed pathway and the presence of a deprotonated (thiolate) nucleophile in water suggests
that the reaction mechanism is borderline between a stepwise route and a concerted process. The
full analysis of the potential energy surface reinforces the addition/elimination mechanism. Despite
of numerous attempts to locate transition structures associated with the leaving group departure
were unsuccessful, presumably because this step is extremely fast.
