Doppler-limited laser spectroscopy of electronic transitions in SnO

Abstract

Laser-induced fluorescence with narrow-band excitation and time resolution has been used for the first time to investigate the quantum-resolved dynamics of excited states of ¹²⁰SnO. Transitions to both the A¹Π and b′³Π(1) excited states were observed. The 1–0 band of SnO A–X is unperturbed, whilst the v′= 3 and v′= 4 levels of SnO A¹Π are perturbed. The v′= 3 level of A¹Π and the v′≈ 13 level of b′³Π(1) show a strong mutual perturbation. The v′= 4 level of A¹Π is somewhat more weakly perturbed by a ¹Δ(1) or ³Π(2) state. Analysis of the spectra of the A–X and b′–X transitions is described.

Lifetimes (τ₀) of selected ro-vibrational states of the A¹Π and b³Π(1) manifolds, and quenching rate constants with O₂(k_M), are reported for the first time as follows:—A¹Π, v′= 1 : τ₀= 160 ± 20 ns; k_M=(2.2 ± 0.6)× 10^–10 cm³ s^–1; A¹Πv′= 3 : τ₀= 140 ± 10 ns; k_M=(6.9 ± 0.6)× 10^–10 cm³ s^–1; A¹Πv′= 4 : τ₀= 130 ± 20 ns; k_M≤ 1.4 × 10^–10 cm³ s^–1; b′³Π(1), v′= 14 : τ₀= 580 ± 34 ns; k_M=(3.6 ± 1.0)× 10^–11 cm³ s^–1