Molecular Beam Investigations of Bimolecular Reactions

Abstract

AbstractIn the present review the attempt has been made to relate the molecular beam results on chemical reactions to the macroscopic reaction rate constants. The review starts with a summary of the phenomenological description of bimolecular reactions. The advantages and disadvantages of this simple description are pointed out. In the second section the collision theory of rate constants is derived and the Boltzmann equation for calculating the rate of a macroscopic reaction under extreme conditions is introduced. The connection between reactive cross sections and chemical forces is emphasized. In the third section the crossed molecular beam method is decribed. Recent measurements of the following properties of reactive collisions are then reviewed: angular distribution of products, integral reactive cross sections, internal excitation of the products and, finally, orientation dependence of reactive cross sections. The review ends with a brief interpretation of the beam data in terms of chemical forces.