Quenching Rate Constants for PCl(bΣ+, v‘ = 0)

Abstract

The reaction of metastable Ar(3P0,2) atoms with PCl3 has been developed as a source of metastable PCl(b1Σ+) molecules in a flow reactor at 300 K. The total quenching rate constants were measured for 23 molecules, and they are in the 2 × 10-14 to 3 × 10-11 cm3 molecule-1 s-1 range. An electronic-to-vibrational (E−V) energy-transfer mechanism is used to discuss the quenching of PCl(b1Σ+), and the experimental rate constants are compared to similar data for PF(b1Σ+), NF(b1Σ+), and NCl(b1Σ+) molecules. An influence of the type of halogen substituent in the reagent molecule on the quenching rate constants is identified, and a role for attractive molecular interactions needs to be added to the E−V model. The Ar(3P0,2) + PCl3 reaction gives vibrationally excited PCl(b1Σ+) molecules and the Δv = +1 and +2 sequences were observed in addition to the Δv = 0 main sequence.