Keith McLauchlan pioneered flash photolysis electron spin resonance (ESR), to provide identification of free radicals in solution, using novel concepts and new technology. It led to the discovery of ‘chemically induced dynamic electron polarisation’ which links photophysics and photochemistry.
This enabled the determination of radical singlet and triplet reaction pathways and the relaxation times of doublets and triplets, and novel studies of site exchange, electron exchange and proton exchange in transient species; the theory was also provided and methods for analysis of polarised spectra delineated. This contributed to the concept of the ‘new’ reaction intermediate, the ‘spin-correlated radical pair’.
Keith has studied this using both transient ESR and reaction yield magnetic resonance (RYDMR) methods, in experiments uniquely designed for normal solution studies. Novel measurements of the electron exchange interaction have resulted. He studied the effects of low magnetic fields on chemical and biochemical reactions via this intermediate, again using original experiments. He is a pioneer of ‘spin chemistry’ and also performed pioneering NMR studies on oriented molecules, double quantum effects and double resonance.