The coordination chemistry of lanthanide and actinide metal ions with hydroxypyridinone-based decorporation agents: orbital and density based analyses

Abstract

Ligand-to-metal charge transfer, orbital-mixing, chelatoaromatic effect and topological constraints control the binding of lanthanide and actinide ions to hydroxypyridinone-based decorporation agents.

Periodic trends and complexation chemistry of tetravalent actinide ions with a potential actinide decorporation agent 5‐LIO(Me‐3,2‐HOPO): A relativistic density functional theory exploration

“…For Th 4+ and Pu 4+ , ten and eight water molecules were considered, respectively, in the primary coordination sphere. We have recently justified the aforementioned choice of hydrated models in our published article . Although some ambiguity remains on the most‐probable hydration number of U 4+ and Np 4+ , ab initio molecular dynamics simulation studies on U 4+ hydration by Atta‐Fynn et al suggested that nine water molecules can be accommodated in the first coordination sphere .…”

“…The initial structural coordinates of the [PuL 2 ] complex for geometry optimization were taken from the reported crystal structure by Gorden et al Recently, we investigated the binding of Ln 3+ , An 3+ , and An 4+ metal ions with the L1 ligand computationally . The applied computational methodologies in these works were noted to produce an excellent correlation with the available experimental information.…”

“…The structural coordinates of the hydrated clusters were taken from Shield et al The choice of the hydrated metal structures was based on previous experimental and theoretical studies . For Th 4+ and Pu 4+ , ten and eight water molecules were considered, respectively, in the primary coordination sphere.…”

“…Abergel and co‐workers have carried out extensive studies using various spectroscopic methods to understand the coordination chemistry and solution thermodynamics of [AnL1] complexes. In conjugation with these experiments, relativistic density functional theory (DFT) studies also have been highly informative to understand the bonding nature of actinides with L1 at a molecular level . These studies demonstrated that the stabilities of [AnL1] complexes depend on many inter‐dependent parameters such as charge and ionic radius of the metal, ligand to metal charge transfer (LMCT) effect, degree of covalency of the metal–ligand bond and also on the chelatoaromatic effect.…”

“…These studies demonstrated that the stabilities of [AnL1] complexes depend on many inter‐dependent parameters such as charge and ionic radius of the metal, ligand to metal charge transfer (LMCT) effect, degree of covalency of the metal–ligand bond and also on the chelatoaromatic effect. Undoubtedly, the relative participation of valence f and d orbitals in actinide–ligand bonding plays a pivotal role in the alteration of the values of the metal binding stability constants …”