| Citation | Distinguished in the study of atom and free radical reactions in the gas phase of spectroscopic methods. He assisted in the first comprehensive examination of the spectra of free radicals in homogeneous explosions using flash photolysis. He discovered the absorption spectra of several free radicals (e.g. the azide, cyclopentdienyl and tropyl radicals): he determined the ionisation potential of the tropyl radical. Later he developed a new method of studying hydrogen atom reactions, and determined the rate constants of a series of nitrogen, hydrogen and oxygen atom reactions important in combustion and in the upper atmosphere. His interest in chemiluminescence yielded a series of important papers on the formation of electronically excited molecules in transfer reactions and recombination reactions. He has developed a photochemical method for studying unimolecular reactions of molecules with known energies. Recently he has studied the rotational spectra of free radicals (NH-2, PH-2, Ph, etc.) by using the Zeeman effect to bring them into resonance with a far infra-red laser. During the last year he has been appointed to be one of the two European members of the U.S. National Academy of Sciences Panel on Atmospheric Chemistry which will report on the effect of chlorofluorocarbons etc. on atmospheric ozone. This shows his high international standing. (Attached: List of 150 publications together with reprints) |