Quenching processes and rate constants for interaction of metastable argon atoms with diatomic and triatomic molecules

Abstract

The rate constants for quenching of metastable Ar(³P₂) atoms by some diatomic and triatomic molecules have been measured in a discharge-flow apparatus at room temperature. The concentration of argon (³P₂) atoms was monitored by absorption spectroscopy as a function of time and of concentration of various quenching gases. The rate constants varied from 1.5 to 50 × 10^–11 cm³ molecule^–1 s^–1. The magnitudes of the rate constants are discussed in relation to the products observed in previous studies from this laboratory. Observations of the electronic quenching and vibrational relaxation of CS(a³Π) by CS₂ and argon, respectively, are reported; the CS(a³Π) molecule was formed by the dissociative excitation reaction between Ar(³P₂) and CS₂.