STUDIES ON THE PRE-EDGE REGION OF THE X-RAY-ABSORPTION SPECTRA OF COPPER(I) OXIDE AND THE DIAMMINECOPPER(I) ION

The distinctive pre-edge feature in the X-ray absorption spectra of copper(I) oxide and the diamminecopper(I) ion at the copper K-edge has been studied using synchrotron radiation. The relative intensities of these features, which are characteristic of copper(I) compounds, have been measured via the peak areas. The intensity of the oxide peak, with regard to the diammine and other two-coordinate copper environments, is anomalous, being reduced by ca. 60%. This is attributed to the macromolecular nature of the oxide, and the formation of intense excitons. Effects due to the small degree of non-stoichiometry may play an additional part in modifying pre-edge intensity by influencing the exciton lifetime.