The past 25 years in chemical kinetics have seen major advances in studyiqg the mechanisms of complex chemical re­ actions, in particular free radical reactions. Many differ­ ent methods have been developed for quantitative studies of elementary chemical reactions. Thousands of rate constants have been measured, for hundreds of diverse chemical reac­ tions. It is becoming more and more difficult for the chemist to orient himself in the voluminous and rapidly growing liter­ ature of chemical reaction kinetics. This leads to major expenditures of time in searching out, collecting. and eval­ uating quantitative kinetic data; to unnecessary repetition (duplication) of research; and to a situation in which the rich material already accumulated in the field of chemical kinetics is very often not fully utilized in comparing, interpreting, and analyzing new experimental data. There is a pressing need for the creation of a series of handbooks on reaction rate constants. Such work was begun several years ago at the initiative of V. N. Kondrat'ev, and is now going forward under his direction at the Institute of Chemical Physics of the USSR Academy of Sciences. This book is devoted to liquid-phase, homolytic reactions. Part One contains data on monomolecular reactions in which molecules decompose to form radicals, as well as data on bi­ molecular and trimolecular reactions that form free radicals.