Isotopically selective ir photodissociation of SeF6

The isotopically selective ir photodissociation of SeF6 is reported. The output from an NH3 laser (780.5 cm−1, 50 mJ, 200 nsec FWHM) is used to photodissociate SeF6, and the five abundant isotopes of Se are all enriched despite the rather small (∼1.6 cm−1/amu) isotope shift of the ν3 vibration. These results are predictable using a simple empirical technique which can be applied equally well to the ir photodissociation of other molecules.