View in EDS

Stabilization of different redox levels of a tridentate benzoxazole amidophenoxide ligand when bound to Co(III) or V(V).

Saved in:
Bibliographic Details
Title: Stabilization of different redox levels of a tridentate benzoxazole amidophenoxide ligand when bound to Co(III) or V(V).
Authors: Safaei, Elham1 (AUTHOR) e.safaei@shirazu.ac.ir, Balaghi, S. Esmael2 (AUTHOR), Chiang, Linus3 (AUTHOR), Clarke, Ryan M.3 (AUTHOR), Martelino, Diego3 (AUTHOR), Webb, Michael I.3 (AUTHOR), Wong, Edwin W. Y.3 (AUTHOR), Savard, Didier3 (AUTHOR), Walsby, Charles J.3 (AUTHOR) cwalsby@sfu.ca, Storr, Tim3 (AUTHOR) tim_storr@sfu.ca
Source: Dalton Transactions: An International Journal of Inorganic Chemistry. 9/21/2019, Vol. 48 Issue 35, p13326-13336. 11p.
Subjects: Solid geometry, Metal bonding, Charge exchange, Electronic structure, Chemical bond lengths
Abstract: A tridentate benzoxazole-containing aminophenol ligand NNOH2 was coordinated to Co and V metal centers and the electronic structure of the resultant complexes characterized by both experimental and theoretical methods. The solid state structure of the Co complex exhibits a distorted octahedral geometry with two tridentate ligands bound in meridional fashion, and coordination-sphere bond lengths consistent with a Co(III) oxidation state. EPR and magnetic data support a S = 1/2 ground state, and a formal electronic description of Co(III)(NNOAP)(NNOISQ) where NNOAP corresponds to an amidophenoxide and NNOISQ to the iminosemiquinone redox level. However, the metrical parameters are similar for both ligands in the solid state, and DFT calculations support delocalization of the ligand radical over both ligands, affording an intermediate ligand redox level Co(III)(NNO1.5−)(NNO1.5−). The vanadyl complex exhibits a distorted octahedral geometry in the solid state consistent with a V(V) metal center and amidophenoxide (NNOAP), acetylacetonate and oxo ligands. The ligand metrical parameters are consistent with significant amidophenoxide to V(V) π donation. Overall, our results highlight the roles of electron transfer, delocalization, and π bonding in the metal complexes under study, and thus the complexity in assignment of the electronic structure in these systems. [ABSTRACT FROM AUTHOR]
Copyright of Dalton Transactions: An International Journal of Inorganic Chemistry is the property of Royal Society of Chemistry and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
Database: Engineering Source
Description
Abstract:A tridentate benzoxazole-containing aminophenol ligand NNOH2 was coordinated to Co and V metal centers and the electronic structure of the resultant complexes characterized by both experimental and theoretical methods. The solid state structure of the Co complex exhibits a distorted octahedral geometry with two tridentate ligands bound in meridional fashion, and coordination-sphere bond lengths consistent with a Co(III) oxidation state. EPR and magnetic data support a S = 1/2 ground state, and a formal electronic description of Co(III)(NNOAP)(NNOISQ) where NNOAP corresponds to an amidophenoxide and NNOISQ to the iminosemiquinone redox level. However, the metrical parameters are similar for both ligands in the solid state, and DFT calculations support delocalization of the ligand radical over both ligands, affording an intermediate ligand redox level Co(III)(NNO1.5−)(NNO1.5−). The vanadyl complex exhibits a distorted octahedral geometry in the solid state consistent with a V(V) metal center and amidophenoxide (NNOAP), acetylacetonate and oxo ligands. The ligand metrical parameters are consistent with significant amidophenoxide to V(V) π donation. Overall, our results highlight the roles of electron transfer, delocalization, and π bonding in the metal complexes under study, and thus the complexity in assignment of the electronic structure in these systems. [ABSTRACT FROM AUTHOR]
ISSN:14779226
DOI:10.1039/c9dt02865j