Mechanism of nucleophilic substitution of N-methyl-4-substituted pyridinium salts

Abstract

variable-temperature accessory, was used to record esr spectra. Computer-simulated spectra were obtained using a computer program written by Griffin.38 Esr spectra recorded at room temperature were produced from solutions electrolyzed in a Varían E-3 electrochemical cell under oxygen-free nitrogen. At low temperatures, radicals were electrolytically generated in an esr vacuum cell designed by Holz89 and modified by Rieke and Rich.40 The cell was degassed by five freeze-pump-thaw cycles before sealing and could maintain a vacuum of at least 10~1 2345678 9Torr for the duration of the experiment. A silver bead reference electrode was used in the cell.Standard three-electrode operational amplifier circuitry was used. All electrical measurements are vs. the saturated sodium chloride colomel reference electrode (SSCE) and are un corrected for junction potentials. The cell design and instrumentation (38) B.

Microenvironment Effects on the Kinetics of the Alkaline Hydrolysis of Bispyridinium Conformers

“…Easy synthetic procedures allow a variety of structural designs for probing microenvironment features. In contraposition, several reactions involving substituted‐pyridinium are highly sensitive to the microenvironment that affects rate constants and products compositions .…”