Photoelectron spectra of molecules. Part 5.—Polycyclic aromatic hydrocarbons

Abstract

A retarding potential cylindrical grid photoelectron spectrometer has been constructed capable of operation up to 300°C. Spectra have been measured for a number of polycyclic benzenoid hydrocarbons. The ionization potentials are compared with those given by other spectroscopic methods and electron impact, with estimates from polarographic oxidation potentials and charge transfer spectra of π molecular complexes, and with values calculated by a SCF MO π approximation. All these alternative procedures lead to significant errors.