Catalyzed thermal decomposition of organic acids. Part 2.—Catalyzed decomposition of cyclopentane- and cycloheptane-carboxylic acids by hydrogen bromide

Abstract

Cyclopentane- and cycloheptane-carboxylic acids decompose by a molecular mechanism into carbon monoxide, water and the corresponding alkene on catalysis by HBr in a seasoned Pyrex vessel. The decomposition is homogeneous and first order in acid and catalyst, HBr. The second order rate constants, expressed by the Arrhenius equations are: k₂= 10^12.17e^{–29 550/RT} cm³ mol^–1 s^–1 for cycloheptanecarboxylic acid and k₂= 10^13.49e^{–34 590/RT} cm³ mol^–1 s^–1 for cyclopentanecarboxylic acid over the temperature range 369.0–434.0°C (R in cal mol^–1).