An electron impact study of the appearance energies of positive ions from Asf3, AsCl3, AsBr3 and AsF5

Abstract A study of the appearance energies of the various positive ions formed by electron impact upon AsF 3 , AsCl 3 , AsBr 3 and AsF 5 has been made. The reactions forming most of the ions have been deduced and heats of formation of either the ions or their accompanying fragments have been determined. All appearance energies were evaluated by the extrapolated voltage difference method. In addition, the translational energies of the fragment ions from AsF 3 were measured and were found to give a linear dependence upon electron energy. Extrapolation to the thermal energy of the ion gave the electron energy equivalent to the heat of the decomposition reaction. In two instances there was excellent agreement with the more conventional appearance energy, in one instance the heat of reaction was less than the conventional appearance energy, and in one the results were not comparable.