Controlling mixed-valence states of pyridyldiimino-bis(o-phenolato) ligand radical in uranyl(VI) complexes.
Dalton Trans
; 2024 Sep 27.
Article
en En
| MEDLINE
| ID: mdl-39330312
ABSTRACT
Combination of a uranyl(VI) ion (UVIO22+) with a redox-active ligand results in characteristic electronic structures that cannot be achieved by either component alone. In this study, three UVIO22+ complexes that bear symmetric or asymmetric 2,6-diiminopyridine-based ligands were synthesized and found to exhibit a first redox couple between -1.17 V and -1.31 V (vs. Fc0/+) to afford singly reduced complexes. The unique electronic transitions of the singly reduced UVIO22+ complexes observed in the NIR region allowed us to combine spectroelectrochemistry and time-dependent density functional theory (TD-DFT) calculations to determine the redox-active site in these UVIO22+ complexes, i.e., to clarify the distribution of the additional unpaired electron. By exploiting the push-pull effect of electron-donating and -withdrawing substituents, the ligand-based π-radical of the singly reduced UVIO22+ complexes, which tends to delocalize over the ligand, can be localized to specific sites.
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Bases de datos:
MEDLINE
Idioma:
En
Revista:
Dalton Trans
Asunto de la revista:
QUIMICA
Año:
2024
Tipo del documento:
Article
País de afiliación:
Japón