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Abstract A mononuclear nonheme manganese(IV)–oxo complex binding the Ce4+ion, [(dpaq)MnIV(O)]+–Ce4+(1‐Ce4+), was synthesized by reacting [(dpaq)MnIII(OH)]+(2) with cerium ammonium nitrate (CAN).1‐Ce4+was characterized using various spectroscopic techniques, such as UV/Vis, EPR, CSI‐MS, resonance Raman, XANES, and EXAFS, showing an Mn−O bond distance of 1.69 Å with a resonance Raman band at 675 cm−1. Electron‐transfer and oxygen atom transfer reactivities of1‐Ce4+were found to be greater than those of MnIV(O) intermediates binding redox‐inactive metal ions (1‐Mn+). This study reports the first example of a redox‐active Ce4+ion‐bound MnIV‐oxo complex and its spectroscopic characterization and chemical properties.
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This content will become publicly available on April 27, 2026
Differentiating Ligand Tailoring and Cation Incorporation as Strategies for Tuning Heterobimetallic Cerium Complexes
Abstract Tuning of redox‐active complexes featuring metals with high coordination numbers by incorporation of secondary redox‐inactive cations has received far less attention than it deserves. Here, appending moderate steric bulk to a tripodal ligand framework has been tested for its influence on secondary‐cation‐driven structural and electrochemical tuning of cerium, a lanthanide that tends to adopt high coordination numbers. Aquasi‐C3‐symmetric cerium(III) complex denoted[Ce]has been prepared that features pendant benzyloxy groups, and this work demonstrates that this species offers a site capable of binding single Na+or Ca2+ions. Electrochemical and UV‐visible spectroscopic studies reveal equilibrium binding affinity of[Ce]for Na+in acetonitrile solvent, contrasting with tight binding of all cations in all other previously studied systems of this type. The modulated cation binding can be attributed to the bulky benzyloxy groups, which impact the thermodynamics of cation binding but do not impede the formation of cerium centers with coordination number 8 upon binding of either Na+or Ca2+. The Ce(IV/III) reduction potential was found to be tunable under the equilibrium binding conditions, highlighting the potentially significant role that controlled structural changes can play in modulating the solution properties of heterobimetallic complexes.
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- Award ID(s):
- 1922649
- PAR ID:
- 10614858
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Chemistry – A European Journal
- Volume:
- 31
- Issue:
- 32
- ISSN:
- 0947-6539
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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