THERMAL DECOMPOSITION OF BENZYL PHENYL ETHER AND BENZYL PHENYL KETONE IN THE PRESENCE OF TETRALIN.

Rates of decomposition of benzyl phenyl ether and benzyl phenyl ketone have been measured in liquid phase over the temperature range 260-440 degree C in the presence of a large excess of Tetralin as a hydrogen donating agent. The decompositions obey the first-order rate law with the values of activation energy and A factor being 53. 2 kcal/mol and 10**1**5**. **2 s** minus **1 for benzyl phenyl ether and 60. 1 kcal/mol and 10**1**3**. **8 s** minus **1 for benzyl phenyl ketone, respectively. The kinetic parameters as well as product distributions can be interpreted by a consecutive mechanism in which the dissociation of the central C-O or C-C bond controls overall rate. The resonance stabilization energies of phenoxy and benzoyl radicals in conform with the proposed mechanism are 10-17 and 13 kcal/mol, respectively. The effect of various solvents or additives on the decomposition is also discussed.