Cation spectra of p-chloroanisole and the heavy atom effect on ionization energy

Abstract

Abstract Vibrationally resolved cation spectra of p-chloroanisole were recorded by ionizing via four vibronic levels through two-color resonant two-photon mass-analyzed threshold ionization (MATI) spectroscopy techniques. The results indicated that the geometry and molecular vibrations 7a, 16b, and 6a of p-chloroanisole in the cationic ground D0 state resemble those in the electronically excited neutral S1 state. The precisely measured adiabatic ionization energy of this molecule was less than that of p-fluoroanisole by 325\u202fcm−1. This can be labeled as a heavy atom effect, which is similar to that observed for para halogen-substituted phenol and aniline.