Reaction between bromophenol blue and aromatic nitrogen bases in chlorobenzene studied with a laser temperature-jump apparatus

Abstract

The kinetics and equilibria involved in the reactions of the indicator acid bromophenol blue (BPB) with pyridine and 2,6-lutidine in chlorobenzene have been investigated with a laser temperature-jump apparatus. The results demonstrate that an intermediate is involved, and may be interpreted in terms of a hydrogen-bonded complex. An enthalpy profile for the reaction is proposed, showing the detailed energetics of the reaction scheme.