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Updated: May 19, 2026

Magnetometric Characterization of Intermediates in the Solid-State Electrochemistry of Redox-Active Metal-Organic Frameworks
Published on: June 9, 2023
Probing the Redox Chemistry of Bimetallic Rare Earth-Catecholate Complexes
Han Geng1, Joshua J M Nelson1, Kevin P Ruoff1
1Vagelos Laboratory for Energy Science and Technology, Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States.
None:
A catecholate proligand, 2,3-dihydroxy-4,6-di-tert-butyl-benzaldehyde ([trenHC═N(H2tBu2cat)3]), capable of binding two metal cations, and its complexes RE2[trenHC═N(tBu2cat)3], RE = La, Nd, and Dy were synthesized. X-ray structures of the complexes showed that C-O bond lengths, ranging from 1.317(4) to 1.334(3) Å, and C-C bond lengths, ranging from 1.426(3) to 1.443(3) Å, of the complexes were consistent with the catecholate form of the ligand in all cases. Cyclic voltammetry (CV) measurements revealed the oxidation of the catecholate ligand arms to the semiquinonate form in all three metal complexes. The oxidation potentials for the metal complexes are modulated to shift toward more positive potentials with increasing Lewis acidity. The results support the hypothesis that differences in ligand oxidation potentials can be exploited for realizing systems for the separation of rare earth metals.
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