Spectroscopic, thermodynamic, and kinetic evidence for a hydrogen-bonded intermediate in fast proton-transfer reactions in aprotic solvents
Abstract
The system Bromophenol Blue + 2,4,6-trimethylpyridine in chlorobenzene shows appreciable quantities of both hydrogen-bonded and ion-pair complex species in protomeric equilibrium; the proton-transfer within the hydrogen bond proceeds at a rate of about 105 sā1, which is much slower than has been generally supposed.