Collision‐induced emission of O₂(b¹Σ → a¹Δg) in the gas phase

In flow tube studies of the quenching of O 2 ( b 1 Σ ), broad band emission of O 2 ( b ): M collision complexes was found to appear under the discrete rotational lines of the 0–0 band of the b 1 Σ → a 1 Δ g electric quadrupole transition at higher oxygen pressures and on addition of foreign gases. Bimolecular rate constants for the collision‐induced emission processes have been derived from the ratio of the intensities of the discrete lines and the continuum as well as from low‐resolution measurements of the relative intensities of the b → a and b → X bands as a function of O 2 and added gas pressure. They range from ≈10 −21 cm 3 s −1 for He to ≈4 × 10 −19 cm 3 s −1 for PCl 3 vapor.