Crossed molecular beam study of chemiluminescent reactions of Group IIIb atoms with O2

Crossed-molecular beams have been used to study reaction of O2 with La to form electronically excited LaO (A 2Π, B 2Σ+, and C 2Π), with Y to form YO (A 2Π), and with Sc to form ScO (A 2Π). No other emitters are observed under single-collision conditions. Relative rate constants for forming product vibrational and electronic states, extracted from wavelength scans, are found to be close to predictions made by prior statistical distributions obtained with no dynamical constraints. The collision energy dependences of the rate constants for forming specific vibrational states, determined by varying the O2 beam velocity, also are close to the prior predictions over a range of about 2–8 kcal/mole.