Spectroscopic studies of the products of reactions of yttrium and scandium atoms with halogen molecules. I. The origin of chemiluminescence

Abstract
Observations of laser induced fluorescence from the products of the reactions of yttrium and scandium atoms with halogen molecules have shown that chemiluminescence does not originate from electronically excited metal monohalide molecules, as previously suggested, but instead arises from electronically excited dihalide molecules,MX2*. Production of the metal dihalides appears to require the formation of vibrationally excited metal monohalides, MX°, in a precursor reaction. Radiative lifetime measurements for chemiluminescent bands are presented.