Collision-energy-resolved Penning ionization electron spectroscopy of substituted ethylenes

Abstract

Collision-energy-resolved Penning ionization electron spectra of NH 2CH 2CH 2CN and HOCH 2CH 2CN by He ∗(2 3S) metastable atoms were observed. Ionization from orbitals extending around CN groups shows large intensity, negative collision energy dependence of partial ionization cross sections (CEDPICS) and negative peak energy shift with respect to the estimated peak positions at ionization energies, and attractive interactions around the nitrile group were obtained by model potential energy calculations. Attractive interactions around NH 2 and OH groups also result in negative CEDPICS and negative peak energy shift. Observed bands in photoelectron spectrum and Penning ionization electron spectrum of NH 2CH 2CH 2CN can be ascribed to ionization from two conformers as calculated by a theoretical method.