Visible and near infrared emission spectra of PCl excited in the reaction of [formula omitted] with PCl 3: Vibrational analysis of PCl A3Π → X3Σ − and b1Σ + → X3Σ −

Abstract

Two band systems of PCl, A 3Π r → X 3Σ − and b 1Σ + → X 3Σ −, have been observed from the reaction of Ar( 3P 2, 0) with PCl 3 at pressures of 1–2 Torr. Seventy-eight bands of P 35Cl and 31 bands of P 37Cl in the region 4000–6000 Å have been assigned to the A 3Π r → X 3Σ − system and include levels with v′ = 0, 1, 2 and v″ = 3–18. The ground state numbering was obtained from a study of the vibrational isotope effect. The (0,0) sequence of the b 1Σ + → X 3Σ − system occurs near 8200 Å and has been observed up to v′ = 10. Vibrational constants for all three states are derived from least-squares fits of the measured bandhead wavenumbers. The A ← X absorption system of PCl reported by Basco and Yee in flash photolysis of PCl 3 was not observed, and is probably due to absorption to a Rydberg state of PCl.