Uncatalysed and metal ion-catalysed hydrolysis of 8-quinolyl sulphate

Abstract

The acid-catalysed hydrolysis of 8-quinolyl sulphate has been studied over the acidity range 1·06–5·29M-HCl at 30 °C. A plot of log k_obs against –H₀ is linear with a slope of 0·99, and Bunnett–Olsen plots give a value of ϕ=+0·04. The solvent deuterium isotope effect, k_D2O/k_H2O= 1·9, and the effect of dioxan content on the rate are all consistent with an A-1 mechanism for the hydrolysis.

The reaction is subject to pronounced catalysis by copper(II) ions in the pH range 5·4–5·8 at 39·8 °C and l= 0·1 M. Possible mechanisms for the metal ion catalysis are considered.