Previous studies have shown that heteropolyoxotungstate coordination to uranyl(VI) and neptunyl(VI) can enhance luminescence from these two actinide centers. We have used these results as the starting point for a systematic investigation of uranyl luminescence in a series of 2:2 uranyl:POM complexes in which subtle factors can be tweaked such as the POM heteroatom ([PW9O34]9-, [GeW9O34]10-, and [SiW9O34]10-), incorporated cations (Na+, K+, NH4+ and Ca2+) and ligand isomer (a, �). Emission spectra show classical well-resolved vibronic structure, with the prominent progression comparable to the energy of the O=U=O symmetric stretch. Solution excitation spectra reveal that the encapsulated uranium atoms can be excited through the uranyl absorption transitions or through the O?U equatorial charge transfer region, but not through the O?W charge transfer region. This systematic study of the most simple 5f0 actinyl system was then extended to a 5f1 neptunyl(VI) system.

Probing the luminescence spectroscopy of uranyl and neptunyl heteropolyoxotungstate complexes

239th National Meeting (2010)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.