Predicting solvent effects in ionic liquids: Extension of a nucleophilic aromatic substitution reaction on a benzene to a pyridine was written by Hawker, Rebecca R.;Haines, Ronald S.;Harper, Jason B.. And the article was included in Journal of Physical Organic Chemistry in 2018.Quality Control of 2,3,4,5,6-Perfluoropyridine The following contents are mentioned in the article:
A nucleophilic aromatic substitution reaction involving a halopyridine electrophile was examined in a series of ionic liquid solvents. This reaction was chosen to test the known solvent effects of ionic liquids on this type of reaction mechanism, previously described with a halobenzene electrophile. The effect of varying the proportion of the ionic liquid in solution was determined, and it was shown that the more ionic liquid present in the reaction mixture, the greater the rate constant enhancement. Temperature-dependent kinetic analyses yielded activation parameters that showed that the rate constant enhancements are controlled by a balance between enthalpic and entropic effects, depending upon the proportion of ionic liquid present. Overall, the rate enhancement is entropically driven, due to organization of the ionic liquid about the electrophile. These results are consistent with what has been observed previously for the nucleophilic aromatic substitution reaction involving a halobenzene electrophile, demonstrating that the solvent effects observed for ionic liquids are general for this type of reaction mechanism and opening the possibility for extending their use through rational selection for reaction control. This study involved multiple reactions and reactants, such as 2,3,4,5,6-Perfluoropyridine (cas: 700-16-3Quality Control of 2,3,4,5,6-Perfluoropyridine).
2,3,4,5,6-Perfluoropyridine (cas: 700-16-3) belongs to pyridine derivatives. In contrast to benzene, Pyridine’s electron density is not evenly distributed over the ring, reflecting the negative inductive effect of the nitrogen atom. Pyridine derivatives are also useful as small-molecule 伪-helix mimetics that inhibit protein-protein interactions, as well as functionally selective GABA ligands.Quality Control of 2,3,4,5,6-Perfluoropyridine