X-Ray Photoelectron Spectroscopy of p-Benzoquinone, Hydroquinone and Their Halogen-Substituted Derivatives

Abstract X-Ray photoelectron spectra of p-benzoquinone, chloranil, bromanil, iodanil, hydroquinone, tetrachlorohydroquinone and chloranilic acid were observed by using the samples freshly deposited in the high vacuum of the spectrometer. The chemical shifts of C ls and O ls levels determined from the XPS spectra are compared with the chemical shifts predicted according to the electrostatic potential model by use of the charge distributions calculated by CNDO/2 method. The charge distributions in the quinone derivatives are successfully estimated by using the observed binding energies of C ls and O ls levels.