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 co pper(I) oxide and the diamminecopper(I) ion at the copper K-edge has b een studied using synchrotron radiation. The relative intensities of t hese features, which are characteristic of copper(I) compounds, have b een 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 macr omolecular nature of the oxide, and the formation of intense excitons. Effects due to the small degree of non-stoichiometry may play an addi tional part in modifying pre-edge intensity by influencing the exciton lifetime.