A study of the thermal decomposition of Se2O2F8 and Te2O2F8, using molecular beam techniques

The thermal decomposition of the vapor phases of the oxygen bridged dimers Se₂O₂F₈ and Te₂O₂F₈ has been studied by mass spectrometry, electric deflection and flight time analysis on a molecular beam generated directly from the decomposition products. Se₂O₂F₈ begins to decompose at ?250°C; the principal products are SeF₄ and O₂, with SeOF₂ as a minor product. Decomposition is complete by ?500°C. There is some decomposition to monomeric SeOF₄ between 200 and 350°C. Te₂O₂F₈ did not begin to decompose until a temperature of 400°C was reached. Again, the principal products observed were TeF₄, O₂, and TeOF₂ with no evidence for decomposition to the monomeric TeOF₄.