Rate constants for concurring radical reactions in solution obtained by kinetic electron spin resonance

It is shown how kinetic electron spin resonance spectroscopy with intermittent radical generation can be used to obtain rate constants of various simultaneous reactions in systems containing more than one kind of transient radicals. The technique is applied to reactions of tert-butyl [(CH₃)₃?] and isopropylol [(CH₃)₂?OH] radicals generated by photolysis of di-tert-butyl ketone and acetone in 2-propanol/acetone mixtures. It yields the rates of generation of the two radicals, the rate constants for their self- and crossterminations and for the reaction of tert-butyl with 2-propanol. The extent of diffusion control of the termination constants is discussed.