Features of the thermal decomposition of diacylic diperoxides in various organic solvents

Thermal decomposition of diacylic diperoxides of various structures was studied: R 1 -C(O)O-O-C(O)-R 2 -C(O)-O-O(O)C-R 1 .It has been shown that the frontier radicals R 1 of the diperoxide molecule influence the rate of the thermal decomposition of diperoxide. The located R 2 radicals that are between peroxide groups practically do not affect the rate of decomposition of peroxide groups. Thethermolysis of didekanoildiperoxyadipinate in various organic solvents has been studied. It has been shown that the primary homolytic dissociation of the peroxide group is accompanied by secondary reactions of chain-inducted decomposition. The reaction medium affects the rate of both primary homolytic dissociation and secondary induced decomposition processes. Correlation equations between the rate constants of the reactions in study and the physicochemical parameters of the solvents were suggested. The correlation equation for effective thermolysis rate constants and the basic physicochemical parameters of solvents at 338 K is the following: k=51.0872+(0.0840±0.0067)В-(0.7854±0.1528)E T - (0.2273±0.0335)V M   (3) N=19; R=0.9548; S=±2.6880; F=1.2519. The basicity, electrophilicity and molar volume of solvent have effect of thermolysis process. The influence of polarization, polarizability and Hilderbrand's function on the thermal decay process is negligible.Correlation equations for effective rate constants for other temperatures are similar. The suggested correlation equations relate the parameters of the transition state of the thermolysis process and the physic-chemical parameters of solvents. Keywords : thermolysis, solvent effects, correlations equations, diperoxide, activation energy.