The ethyl radical: Photoionization and theoretical studies

Abstract

The ethyl radical has been produced by the F+C2H6 reaction, and studied by photoionization mass spectrometry. The adiabatic ionization potential (IP) is found to be 8.117±0.008 eV. The radical and cation have been studied by the G1 level of molecular orbital theory. The calculated adiabatic ionization potential is 8.06 eV. On the basis of both experiment and theory, it is concluded that the cation in its ground state has a bridged structure. The adiabatic value resolves a previous inconsistency involving ΔH○f(C2H5), ΔH○f(C2H+5) and IP (C2H5). Broad autoionizing structures are observed at higher energy. These features can be rationalized as Rydberg states converging to the first excited state 3A″ calculated to be at 12.05 eV.