Abstract

Many chemical and biological reactions proceed on a potential surface with a low barrier or lack of barrier from reactant to product along the reaction coordinate¹,². In a barrierless case, the interaction between the surrounding medium and reactants (or products) provide the only frictional force in affecting the chemical reactions. In general, the frictional force includes two parts: frictional force from the solvent and from non-reactive vibrational modes of reactants or products. Thus, from the perspective of chemical reactions in solution, a barrierless reaction is a prototype in studying both the interactions between reactants(or products) with the surrounding medium and the role of vibrational relaxation during the course of chemical reaction. In this work, we choose triphenylmethane dye molecules: malachite green and crystal violet in alcohol solutions as two model systems to investigate the nature of the barrierless process at initial time and the effect of both solvent and intramolecular vibrational modes during the reaction.

© 1994 Optical Society of America