Kinetics and Mechanism of the Thermal and Hydrolytic Decomposition Reaction of Rosocyanin

ABSTRACT Spiroborate esters of curcumin find applications in the field of medicinal and analytical chemistry. The present paper reports the hydrolytic and thermal stability of rosocyanin, a 1:2 spiroborate ester of curcumin used for the photometric estimation of boron in different matrices. The effect of temperature, pH, and solvents was monitored spectrophotometrically for the hydrolysis of rosocyanin. The reaction followed first‐order kinetics, and the reaction rate enhanced with an increase in the percentage of water in an aqueous organic mixture, temperature, and pH. 11B NMR and UV–visible spectra were used to identify the hydrolysis product. The possible mechanistic route for the hydrolysis of rosocyanin was proposed. Solid‐state stability of rosocyanin was investigated by thermogravimetric analysis, and the data were analyzed using different solid‐state reaction models to find the suitable reaction model. Kinetic parameters associated with its thermal decomposition were calculated using Flynn–Wall–Ozawa and Kissinger–Akahira–Sunose isoconversional methods and were compared.