Beyond Biological Chelation: Coordination of f‐Block Elements by Polyhydroxamate Ligands

Abstract

The promise of polyhydroxamic acid ligands for the selective chelation of the f-elements is becoming increasingly more apparent. The initial studies of polyhydroxamic acid siderophores showed the formation of highly stable complexes with Pu(IV), but a higher preference for Fe(III) hindered effective applications. The development of synthetic routes toward highly pure and customizable ligands containing multiple hydroxamic acids allowed for the growth of new classes of compounds. While the first round of these ligands focused on the incorporation of siderophore-like frameworks, the new synthetic strategies led to small molecules of various frameworks and even resins for applications in the field of f-element separations and biological desorption. Unfortunately, a lack of consistent stability constant data makes direct comparisons across this body of work difficult. More studies into the stability constants and separations of the f-elements in a variety of pH ranges is necessary to truly realize the potential for polyhydroxamic acid ligands.

Controlling the Reduction of Chelated Uranyl to Stable Tetravalent Uranium Coordination Complexes in Aqueous Solution

“…As the use of actinides in both the nuclear power and defense sectors over the past 70 years has resulted in environmental releases of radionuclides generated during associated activities, − the development of aqueous actinide chelation chemistry remains continuously relevant. , Understanding the fundamental bonding interactions of individual actinide cations is critical for ongoing efforts focused on improving actinide decorporation therapies and developing new environmental remediation strategies. This is particularly true for the highly water-soluble uranyl cation, U VI O 2 2+ , which is the predominant form of uranium (U) found in the environment. , The significant mobility of the uranyl cation introduces risks for radiological contamination, which is a crucial public health issue, as uranium exhibits both chemical and radiological toxicity .…”

Hydroxamic Acid: An Underrated Moiety? Marrying Bioinorganic Chemistry and Polymer Science

“…38,39 Motivated by the enormous importance of hydroxamic acidbased siderophores in nature, a broad scope of synthetic, biomimetic siderophores was developed in recent years. 41 ■ BIOSYNTHESIS OF HYDROXAMIC ACIDS Hydroxamic acids in nature are typically found in their Nalkylated structure, that is, as secondary N-hydroxyamides as a result of the biosynthesis pathway. 36 The biosynthesis of hydroxamic acids was investigated at the example of the production of deferoxamine E (DFO-E) in Streptomyces coelicolor.…”

“…93−96 Also, removal of uranium from salt water was demonstrated as a possible application of resin-bound hydroxamic acids (Table 2). 41,97 The affinity order for the binding of rare earth metals with a resin load of up to 10% was reported as La(III) > Nd(III) > Sm(III) > Gd(III) > Tb(III). 98 Similar applications have been shown with starch-graf t-PMA polymers that were modified by hydroxylamine to hydroxamic acids.…”

Polyhydroxamic acid as an efficient metal chelator and flocculant for wastewater treatment

“…Flocculation performance and effectiveness of hydroxamic acid containing flocculants were reported in several publications, such as the settlement of red mud in the Bayer process of the alumina process 36,37 . Recently, the selective chelation of the polyhydroxamic acid ligands with f‐block elements was investigated 38 . However, the flocculation performance of commercially available acrylamide and acrylic acid‐based organic flocculants was rarely reported for flocculation effectiveness, for the removal of suspended solids and turbidity from industrial wastewater.…”