Mass Spectra at Low Ionizing Voltage and Bond Dissociation Energies of Molecular Ions from Hydrocarbons

Abstract

Relative yields of parent and principal fragment ions from four paraffins and olefins by electron impact are measured for the first time. The characteristic features of the ion yields can be classified into four types related with the ionizing voltages. The decomposition processes for some fragment ions can be explained under some assumptions, and those for forbidden ions C₂H₅⁺ from isobutane and cis-2-butene under the assumption of hydrogen rerrangement.