Kinetics and mechanism of the hydrolysis of dichloranhydrides of carboxylic acids

Abstract

1. A spectrophotometric method has been used to investigate hydrolysis of the chloranhydridcs of phthalic (PC) and terephthalic (TPC) acids in aqueous dioxan in the temperature range 10–65°. 2. The constant concentration activation energy of the reaction and the preexponential multiplier increase with increase in water concentration in the mixture. 3. The relations between the reaction rate and the polarity of the medium have been used to find the isodielectric activation energies for different values of ɛ in the medium, and it has been shown that Ee increases with increase in dielectric constant of the solution. Hydrolysis of both chloranhydrides shows a “compensation effect” between Ee and log10A. 4. A reaction mechanism is proposed for the hydrolysis of chloranhydrides, and the dimensions and polarity of the activated complex have been found.