KINETICS OF INTRAMOLECULAR AND INTERMOLECULAR REACTIONS OF BENZYLCHLOROCARBENE

Photolysis of 3-chloro-3-benzyldiazirine in tetramethylethylene gives E- and Z-beta-chlorostyrenes and cyclopropane. Relative rate studies show that the styrenes to cyclopropane ratio increases with increasing diazirine concentration. This permits the determination of the ratio k(D)/k(i) = 8 where k(D) is the rate constant for the reaction of carbene with diazirine and k(i) is the rate constant for the 1,2-hydrogen atom shift of carbene. Laser flash photolysis yields the first absolute rate constant for the reaction of a chlorocarbene with diazirine and a value of 7.7 for k(D)/k(i).