Abstract

Two different cases, (1) thermal initiation and (2) collisionless IR multiple photon (MP) initiation, of initiating the model reaction of the successive decay of polyatomic molecules ABCAB + C,ABA + B are considered for the case when the intermediate product AB is desired. In the case when the desired product AB is thermally less stable than the original one ABC the high output of AB under the thermal initiation is impossible. However by means of IR MP initiation one can obtain a high yield of the desired product, i.e., nearly 100%. The reduction of the chemical reaction pathways takes place for the IR MP initiation. This is due to the extreme intermolecular nonequilibrium achieved under IR MP initiation of the reaction. Unlike the thermal initiation when all the reaction products are of equally high temperature, under IR MP initiation the temperature of the intermediate product TAB is lower than that of the original one TABC and a further decay of the AB species does not occur.