Kinetic aspects of spin trapping

Abstract

Kinetics are described of the spin-trapping process itself, based on indirect methods such as radical clocks and other competition methods, and also direct methods based on flash photolysis and pulse radiolysis. The stability of spin traps and their dimerization are discussed, as is the stability of spin adducts, once formed. Caution is given over the utilisation of spin traps in photo - and redox systems where the spin trap can undergo excitation and/or dissociation to lead to radicals which undergo trapping processes to give potentially misleading spectral data. The use of well-authenticated spin trapping kinetic data to examine rates of ring-opening and - closing and isomerization reactions is covered. The role of spin trapping as a probe of biochemical processes is also included, with particular reference to the trapping of hydroxyl and Superoxide radicals.