First observation of [Pu6(OH)4O4]12+ cluster during the hydrolytic formation of PuO2 nanoparticles using H/D kinetic isotope effect.

New insights are provided about the formation mechanism of PuO₂ nanoparticles (NPs) by investigating an unprecedented kinetic isotope effect observed during their hydrolytic synthesis in H₂O or D₂O and attributed to OH/OD zero point energy difference. The signature of a Pu(IV) oxo–hydroxo hexanuclear cluster, appearing as an important intermediate during the formation of the 2 nm PuO₂ NPs (synchrotron SAXS/XAS), is further revealed indicating that their formation is controlled by H-transfer reactions occurring during hydroxo to oxo-bridge conversions. [ABSTRACT FROM AUTHOR]