The three-body recombination and dissociation of diatomic molecules: A comparison between theory and experiment

Abstract

The modified phase-space theory of reaction rates has been used to predict the three-body recombination and dissociation rate coefficients of the diatomic gas molecules: H2, N2, O2, F2, Cl2, Br2, I2, HF, HCl, CO and NO, in the presence of argon as a collision partner. The ability of the theory to quantitatively predict and correlate both low-temperature recombination rate measurements and high-temperature dissociation rate measurements is substantial. The success of the theory clearly illustrates the importance of the weak attractive forces between the recombining atoms and argon atoms for recombination at low temperatures, the marked reduction in the rates at high temperatures due to nonequilibrium distributions in the vibrational state populations of the molecules, and the major contributions to reaction progress via electronically excited molecular states at all temperatures for such molecules as N2 and CO.