REACTION OF SR WITH CH2CL2, CHCL3, AND CCL4 - LASER-INDUCED FLUORESCENCE STUDIES ON RELAXED AND UNRELAXED SRCL

A combined spectroscopic and chemical study is performed on thermal an d nonthermal SrCl. The DELTAnu = 0 sequence of the B2SIGMA <-- X2SIGMA electronic transition is used for absorption spectroscopy up to high vibrational quantum numbers nu with the technique of laser-induced flu orescence. Effective spectroscopic constants are derived that are vali d up to high nu. SrCl is investigated both as a product of oven reacti ons and of the reaction of Sr beam atoms with the chlorinated methane molecules in the observation region (henceforth referred to as the gas -phase reaction), leading to thermal and nonthermal spectra, respectiv ely. One of the possible oven reactions, the metal-salt reaction Sr SrCl2 --> 2SrCl, yields a thermal spectrum with a vibrational temperat ure equal to the oven temperature. The reaction Sr + CH2Cl2 --> SrCl CH2Cl apparently has a small cross section for the gas phase, since o nly a thermal spectrum is observed. The reaction Sr + CHCl3 --> SrCl CHCl2 yields a combined thermal and nonthermal spectrum. The gas-phas e reaction leads to SrCl product molecules with a vibrational populati on distribution peaked around nu = 17. The reaction Sr + CCl4 --> SrCl + CCl3 has a large cross section for the gas phase with a distributio n peaked around nu = 27. In this reaction, nearly all available energy is disposed into internal energy of the SrCl product.