Ionization and appearance potentials in organic chemistry

Abstract

1. The first adiabatic potentials of the ionization of cis and trans iosmers with respect to the linkage of the rings of bicyclo[4.3.0]nonane and bicyclo [4.4.0] decane are practically identical. The relative ionization potentials of the stereoisomers measured by the electron-impact method differ by ∼0.05 eV. 2. The “relative” appearance potentials of the ions with masses of 109, 96, 95, 82, 81, 68, and 67 for the stereoisomers of these two series have been measured. The difference in the appearance potentials of the ions with a mass of 96 is equal to the difference in the enthalpy of formation of the geometric isomers, with reversed sign. For the other ions, either only qualitative correlation of this type is observed or it is completely absent. 3. The “relative” appearance potentials can apparently be used to determine the difference in the heats of formation of the geometric isomers in the case of substituted bicyclo[4.3.0]nonanes and bicyclo[4.4.0]decanes.