The complexation of Pu(VI) with oxalate (L2-) in aqueous solution is scrutinized with an absorption spectral titration. The previously neglected 1:3 complex of PuO2L34- is identified, and the stability constants of the three successive complexes (PuO2L(aq), PuO2L22-, and PuO2L34-) are calibrated to be 5.23 ± 0.04, 9.21 ± 0.08, and 10.61 ± 0.12, respectively.
Yang et al. (Wed,) studied this question.