Why Selenoxanthone Gives an MC with Bromine: An Examination of Electronic States of Xanthones and Xanthenes by Electron Spectroscopy and ab Initio MO Calculations

The PIES and UPS spectra of xanthone (1a), thioxanthone (1b), and selenoxanthone (1c) were measured, together with those of the corresponding xanthene (2a), thioxanthene (2b), and selenoxanthene (2...