Radiolytic Evaluation of 3,4,3-LI(1,2-HOPO) in Aqueous Solutions

Yufei Wang; Stephen P Mezyk; Jeffrey R McLachlan; Travis S Grimes; Peter R Zalupski; Hailie M T O'Bryan; Andrew R Cook; Rebecca J Abergel; Gregory P Horne

doi:10.1021/acs.jpcb.3c01469

Radiolytic Evaluation of 3,4,3-LI(1,2-HOPO) in Aqueous Solutions

J Phys Chem B. 2023 May 4;127(17):3931-3938. doi: 10.1021/acs.jpcb.3c01469. Epub 2023 Apr 21.

Authors

Yufei Wang^{1

2

3}, Stephen P Mezyk⁴, Jeffrey R McLachlan⁵, Travis S Grimes³, Peter R Zalupski³, Hailie M T O'Bryan², Andrew R Cook⁶, Rebecca J Abergel^{1

2}, Gregory P Horne³

Affiliations

¹ Department of Nuclear Engineering, University of California, Berkeley, California 94720, United States.
² Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States.
³ Center for Radiation Chemistry Research, Idaho National Laboratory, Idaho Falls, Idaho 83415, United States.
⁴ Department of Chemistry and Biochemistry, California State University Long Beach, Long Beach, California 90804, United States.
⁵ Department of Chemistry and Biochemistry, Florida International University, Miami, Florida 33199, United States.
⁶ Department of Chemistry, Brookhaven National Laboratory, Upton, New York 11973, United States.

PMID: 37084416
DOI: 10.1021/acs.jpcb.3c01469

Abstract

The octadentate hydroxypyridinone ligand 3,4,3-LI(1,2-HOPO) (abbreviated as HOPO) has been identified as a promising candidate for both chelation and f-element separation technologies, two applications that require optimal performance in radiation environments. However, the radiation robustness of HOPO is currently unknown. Here, we employ a combination of time-resolved (electron pulse) and steady-state (alpha self-radiolysis) irradiation techniques to elucidate the basic chemistry of HOPO and its f-element complexes in aqueous radiation environments. Chemical kinetics were measured for the reaction of HOPO and its Nd(III) ion complex ([Nd^III(HOPO)]^-) with key aqueous radiation-induced radical transients (e_aq^-, H^• atom, and ^•OH and NO₃^• radicals). The reaction of HOPO with the e_aq^- is believed to proceed via reduction of the hydroxypyridinone moiety, while transient adduct spectra indicate that reactions with the H^• atom and ^•OH and NO₃^• radicals proceeded by addition to HOPO's hydroxypyridinone rings, potentially allowing for the generation of an extensive suite of addition products. Complementary steady-state ²⁴¹Am(III)-HOPO complex ([²⁴¹Am^III(HOPO)]^-) irradiations showed the gradual release of ²⁴¹Am(III) ions with increasing alpha dose up to 100 kGy, although complete ligand destruction was not observed.