1297532-22-9Relevant academic research and scientific papers
Combinatorial design of multimeric chelating peptoids for selective metal coordination
Ricano, Abel,Captain, Ilya,Carter, Korey P.,Nell, Bryan P.,Deblonde, Gauthier J.-P.,Abergel, Rebecca J.
, p. 6834 - 6843 (2019)
Current methods for metal chelation are generally based on multidentate organic ligands, which are generated through cumbersome multistep synthetic processes that lack flexibility for systematically varying metal-binding motifs. Octadentate ligands incorporating hydroxypyridinone or catecholamide binding moieties onto a spermine scaffold are known to display some of the highest affinities towards f-elements. Enhancing binding affinity for specific lanthanide or actinide ions however, necessitates ligand architectures that allow for modular and high throughput synthesis. Here we introduce a high-throughput combinatorial library of 16 tetrameric N-substituted glycine oligomers (peptoids) containing hydroxypyridinone or catecholamide chelating units linked via an ethylenediamine bridge and, for comparison, we also synthesized the corresponding mixed ligands derived from the spermine scaffold: 3,4,3-LI(1,2-HOPO)2(CAM)2 and 3,4,3-LI(CAM)2(1,2-HOPO)2. Coordination-based luminescence studies were carried out with Eu3+ and Tb3+ to begin probing the properties of the new ligand architecture and revealed higher sensitization efficiency with the spermine scaffold as well as different spectroscopic features among the structural peptoid isomers. Solution thermodynamic properties of selected ligands revealed different coordination properties between the spermine and peptoid analogues with Eu3+ stability constants log β110 ranging from 28.88 ± 3.45 to 43.97 ± 0.49. The general synthetic strategy presented here paves the way for precision design of new specific and versatile ligands, with a variety of applications tailored towards the use of f-elements, including separations, optical device optimization, and pharmaceutical development.
Hexadentate terephthalamide(bis-hydroxypyridinone) ligands for uranyl chelation: Structural and thermodynamic consequences of ligand variation (1)
Szigethy, Geza,Raymond, Kenneth N.
supporting information; experimental part, p. 7942 - 7956 (2011/07/06)
Several linear, hexa- and tetradentate ligands incorporating a combination of 2,3-dihydroxy-terephthalamide (TAM) and hydroxypyridinone-amide (HOPO) moieties have been developed as uranyl chelating agents. Crystallographic analysis of several {UO2[TAM(HOPO)2]}2- complexes revealed a variable and crowded coordination geometry about the uranyl center. The TAM moiety dominates the bonding in hexadenate complexes, with linker rigidity dictating the equality of equatorial U-O bonding. Hexadentate TAM(HOPO)2 ligands demonstrated slow binding kinetics with uranyl affinities on average 6 orders of magnitude greater than those of similarly linked bis-HOPO ligands. Study of tetradentate TAM(HOPO) ligands revealed that the high uranyl affinity stems primarily from the presence of the TAM moiety and only marginally from increased ligand denticity. Uranyl affinities of TAM(HOPO)2 ligands were within experimental error, with TAM(o-phen-1,2-HOPO)2 exhibiting the most consistent uranyl affinity at variable pH.
