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Rajh T, Masson E, Latt KZ, Smith A, Brugh AM, Dandu N, Trainer D, Curtiss LA, Ngo AT, Hla SW. Light- and Chemical-Doping-Induced Magnetic Behavior of Eu Molecular Systems. Inorg Chem 2023; 62:12721-12729. [PMID: 37506323 DOI: 10.1021/acs.inorgchem.3c01154] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/30/2023]
Abstract
Variable temperature electron paramagnetic resonance (VT-EPR) was used to investigate the role of the environment and oxidation states of several coordinated Eu compounds. We find that while Eu(III) chelating complexes are diamagnetic, simple chemical reduction results in the formation of paramagnetic species. In agreement with the distorted D3h symmetry of Eu molecular complexes investigated in this study, the EPR spectrum of reduced complexes showed axially symmetric signals (g⊥ = 2.001 and g∥ = 1.994) that were successfully simulated with two Eu isotopes with nuclear spin 5/2 (151Eu and 153Eu with 48% and 52% natural abundance, respectively) and nuclear g-factors 151Eu/153Eu = 2.27. Illumination of water-soluble complex Eu(dipic)3 at 4 K led to the ligand-to-metal charge transfer (LMCT) that resulted in the formation of Eu(II) in a rhombic environment (gx = 2.006, gy = 1.995, gz = 1.988). The existence of LMCT affects the luminescence of Eu(dipic)3, and pre-reduction of the complex to Eu(II)(dipic)3 reversibly reduces red luminescence with the appearance of a weak CT blue luminescence. Furthermore, encapsulation of a large portion of the dipic ligand with Cucurbit[7]uril, a pumpkin-shaped macrocycle, inhibited ligand-to-metal charge transfer, preventing the formation of Eu(II) upon illumination.
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Affiliation(s)
- Tijana Rajh
- Nanoscience and Technology Division, Argonne National Laboratory, 9700 S Cass Ave, Argonne, Illinois 60540, United States
- School of Molecular Sciences, Arizona State University, 551 E University Dr, Tempe, Arizona 85281, United States
| | - Eric Masson
- Department of Chemistry, Ohio University, Athens, Ohio 45701, United States
| | - Kyaw Zin Latt
- Nanoscience and Technology Division, Argonne National Laboratory, 9700 S Cass Ave, Argonne, Illinois 60540, United States
| | - Ashton Smith
- Department of Chemistry, Ohio University, Athens, Ohio 45701, United States
| | - Alexander M Brugh
- School of Molecular Sciences, Arizona State University, 551 E University Dr, Tempe, Arizona 85281, United States
| | - Naveen Dandu
- Department of Chemical Engineering, University of Illinois at Chicago, Chicago, Illinois 60608, United States
- Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Daniel Trainer
- Nanoscience and Technology Division, Argonne National Laboratory, 9700 S Cass Ave, Argonne, Illinois 60540, United States
| | - Larry A Curtiss
- Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Anh T Ngo
- Department of Chemical Engineering, University of Illinois at Chicago, Chicago, Illinois 60608, United States
- Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Saw-Wai Hla
- Nanoscience and Technology Division, Argonne National Laboratory, 9700 S Cass Ave, Argonne, Illinois 60540, United States
- Nanoscale & Quantum Phenomena Institute, and Department of Physics & Astronomy, Ohio University, Athens, Ohio 45701, United States
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Kavok N, Klochkov V, Averchenko K, Grygorova G, Sedyh O, Yefimova S. Stability optimization of orthovanadate nanoparticles in biocompatible media. J DISPER SCI TECHNOL 2022. [DOI: 10.1080/01932691.2022.2159832] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Nataliya Kavok
- Institute for Scintillation Materials NAS of Ukraine, Kharkov, Ukraine
| | - Vladimir Klochkov
- Institute for Scintillation Materials NAS of Ukraine, Kharkov, Ukraine
| | | | - Ganna Grygorova
- Institute for Scintillation Materials NAS of Ukraine, Kharkov, Ukraine
| | - Olga Sedyh
- Institute for Scintillation Materials NAS of Ukraine, Kharkov, Ukraine
| | - Svetlana Yefimova
- Institute for Scintillation Materials NAS of Ukraine, Kharkov, Ukraine
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