Cat-N-BQ and Cat-N-SQ denote the mononegative (Cat-N-BQ−) or dinegative (Cat-N-SQ2−) radical forms of the tridentate Schiff-base ligand 3,5-di-tert-butyl-1,2-quinone-1-(2-hydroxy-3,5-di-tert-butylphenyl)imine.
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Full Paper
Coexistence of Two Thermally Induced Intramolecular Electron Transfer Processes in a Series of Metal Complexes [M(Cat-N-BQ)(Cat-N-SQ)]/[M(Cat-N-BQ)2] (M=Co, Fe, and Ni) bearing Non-Innocent Catechol-Based Ligands: A Combined Experimental and Theoretical Study†
Article first published online: 23 APR 2010
DOI: 10.1002/chem.200902568
Copyright © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Additional Information
How to Cite
Evangelio, E., Bonnet, M.-L., Cabañas, M., Nakano, M., Sutter, J.-P., Dei, A., Robert, V. and Ruiz-Molina, D. (2010), Coexistence of Two Thermally Induced Intramolecular Electron Transfer Processes in a Series of Metal Complexes [M(Cat-N-BQ)(Cat-N-SQ)]/[M(Cat-N-BQ)2] (M=Co, Fe, and Ni) bearing Non-Innocent Catechol-Based Ligands: A Combined Experimental and Theoretical Study. Chemistry - A European Journal, 16: 6666–6677. doi: 10.1002/chem.200902568
- †
Publication History
- Issue published online: 2 JUN 2010
- Article first published online: 23 APR 2010
- Manuscript Received: 17 SEP 2009
Funded by
- Spanish Government. Grant Number: MAT 2009-13977-C03-03
- Network of Excellence MAGMAnet
- Comunitat de Treball dels Pirineus/Communauté de Travail des Pyrénées
Keywords:
- electron transfer;
- magnetic properties;
- mixed-valent compounds;
- radicals;
- valence tautomerism
Graphical Abstract
One complex, different processes: The different intermolecular electron transfer (IET) processes of a series of [M(Cat-N-BQ)(Cat-N-SQ)]/[M(Cat-N-BQ)2] complexes (in which M=Co, Fe, and Ni, and Cat-N-BQ and Cat-N-SQ denote the mono- or dinegative radical forms of the tridentate Schiff base ligand 3,5-di-tert-butyl-1,2-quinone-1-(2-hydroxy-3,5-di-tert-butylphenyl)imine, respectively) have been studied by variable-temperature UV/Vis and NMR spectroscopies, and theoretical calculations. Depending on the metal ion, different behavior is observed.
Abstract
The different thermally induced intermolecular electron transfer (IET) processes that can take place in the series of complexes [M(Cat-N-BQ)(Cat-N-SQ)]/[M(Cat-N-BQ)2], for which M=Co (2), Fe (3) and Ni(4), and Cat-N-BQ and Cat-N-SQ denote the mononegative (Cat-N-BQ−) or dinegative (Cat-N-SQ2−) radical forms of the tridentate Schiff-base ligand 3,5-di-tert-butyl-1,2-quinone-1-(2-hydroxy-3,5-di-tert-butylphenyl)imine, have been studied by variable-temperature UV/Vis and NMR spectroscopies. Depending on the metal ion, rather different behaviors are observed. Complex 2 has been found to be one of the few examples so far reported to exhibit the coexistence of two thermally induced electron transfer processes, ligand-to-metal (IETLM) and ligand-to-ligand (IETLL). IETLL was only found to take place in complex 3, and no IET was observed for complex 4. Such experimental studies have been combined with ab initio wavefunction-based CASSCF/CASPT2 calculations. Such a strategy allows one to solicit selectively the speculated orbitals and to access the ground states and excited-spin states, as well as charge-transfer states giving additional information on the different IET processes.