A study of the carbonate complexation of Cm III and Eu III by time-resolved laser fluorescence spectroscopy

Abstract

Carbonate complexation of Cm III and Eu III is studied by time-resolved laser-induced fluorescence spectroscopy (TRLFS). The carbonato species M(CO 3) +, M(CO 3) 2 − and M(CO 3) 3 3− (MCm III and Eu III) are characterized by measuring excitation and emission spectra, and lifetime. Stability constants for the first carbonato complex in 0.1 M NaClO 4 are found to be log β 11 = 6.65 ± 0.07 for Cm(CO 3) + and log β 11 = 6.57 ± 0.08 for Eu(CO 3) +. The constant for Cm IIIcompares well with the values for Am III derived spectroscopically and by solubility measurement. No difference is found for the stability constant of Eu(CO 3) + in the excited state as determined by TRLFS and in the ground state as determined by solubility measurement.