Free radicals by mass spectrometry. XLIL Ionization potentials and ionic heats of formation for C1—C4 alkyl radicals

摘要: Ionization potentials for C1—C4 alkyl free radicals have been re-measured by electron impact, using an energy-resolved beam from a double-hemispherical electrostatic monochromator. From these values and kinetic data heats of formation the radicals, ionic ions calculated. New four isomeric butyl are given. The ionization efficiency curves simpler show linear sections corresponding to excitation vibrational levels; larger segments not resolved only smooth upward curvature is seen. In disagreement with earlier results, no evidence low-lying excited states could be found, either parent or fragment ions.