The laser excitation spectrum of CH2Se and CD2Se in the near infrared

摘要

The polymers of CH2Se and CD2Se were pyrolyzed at 700thinsp;deg;C to yield monomeric selenoformaldehyde. Laser excitation spectra of these molecules were recorded. The origin of the weak singletndash;singletAtilde;thinsp;1A2larr;Xtilde;thinsp;1A1system in CD2Se was observed at 13thinsp;631.5 cmminus;1while that of CH2Se has been calculated to be at 13thinsp;555 cmminus;1. The much more extensive and intense singletndash;tripletatilde;thinsp;3A2larr;Xtilde;thinsp;1A1systems of CH2Se/CD2Se have origins at 12thinsp;171.0/12thinsp;262.7 cmminus;1. A double minimum potential energy function was used to fit the triplet state ngr;rsquo;4inversion levels and was found to be similar to that observed for thioformaldehyde.