The monomeric character of xenon hexafluoride vapor. The mass spectroscopy of noble gas binary fluorides and xenon oxide tetrafluoride

Positive ion mass spectra have been obtained for KrF2, XeF2, XeF4, XeF6, and XeOF4 using 60 or 70 V electron impact ionization and a molecular beam source designed especially for reactive fluorides. Flight time distribution measurements have been made for neutral XeF6. Both these and the mass spectrometric fragmentation pattern indicate monomeric species in the saturated vapor. Associated (dimer) molecules can be obtained by isentropic expansion of XeF6; these are detected as dimer ions at one part in 104 of the monomeric ions in the mass spectrum. Electric deflection measurements on XeF6 vaporizing from inlets at temperatures from −19 to 40 °C showed no focusing effect.