Determination by the mass spectrometric Knudsen cell method and discussion of the dissociation energies of the molecules Se2(g), SSe(g) and SeTe(g)

Abstract

The dissociation energies of the molecules Se₂(g), SSe(g) and SeTe(g), D^°₀(Se₂)= 78.1 ± 2.0, D^°₀(SSe)= 87.8 ± 1.6 and D^°₀(SeTe)= 70.1 ± 1.2 kcal mol^–1 are determined by the mass spectrometric Knudsen cell method. For Se₂, the result confirms the higher of two spectroscopically possible values, D^°₀(Se₂)= 78.65 ± 0.06 kcal mol^–1, which has not been favoured hitherto on spectroscopic grounds. The spectroscopic observations are, therefore, critically examined to show that they allow this value.