Structure, spectroscopy and magnetic properties of Zn, Mn and Co complexes of a pyridine bis(imine) bis(nitroxide) ligand
Abstract
A pyridine-diimine (N3) pincer ligand, denoted L, was functionalized with two TEMPO moieties. The Zn 2+ , Mn 2+ and Co 2+ complexes were isolated and structurally characterized, showing a pentacoordinated metal center, with two exogenous chloride ligands. All exhibit the typical 3-line pattern of nitroxide radicals in their EPR spectrum. The magnetic interaction between the metal and the nitroxide moieties is negligible, as demonstrated by SQUID magnetometry. Both the ligand and complexes exhibit a reversible oxidation wave at 0.30-0.35 V vs. Fc + /Fc, which corresponds to the simultaneous oxidation of both TEMPO groups into oxoammonium species. This is verified by a quenching of the nitroxide lines in the EPR spectrum during controlled potential electrolysis, as well as the appearance of shoulders around 450-500 nm in UV-Vis spectroscopy. DFT calculations support a ligandcentered oxidation, and the high spin configuration of the complexes.
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BibTeX
@article{mella2026structure,
title = {{Structure, spectroscopy and magnetic properties of Zn, Mn and Co complexes of a pyridine bis(imine) bis(nitroxide) ligand}},
author = {Lorna Ramirez Mella and Christian Philouze and Dominique Luneau and Jennifer K Molloy and Fabrice Thomas},
journal = {Inorganica Chimica Acta},
year = {2026},
month = sep,
doi = {10.1016/j.ica.2026.123210},
url = {https://univ-grenoble-alpes.hal.science/hal-05759914v1},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Structure, spectroscopy and magnetic properties of Zn, Mn and Co complexes of a pyridine bis(imine) bis(nitroxide) ligand
AU - Lorna Ramirez Mella
AU - Christian Philouze
AU - Dominique Luneau
AU - Jennifer K Molloy
AU - Fabrice Thomas
PY - 2026
DA - 2026/09/23
JO - Inorganica Chimica Acta
DO - 10.1016/j.ica.2026.123210
UR - https://univ-grenoble-alpes.hal.science/hal-05759914v1
AB - A pyridine-diimine (N3) pincer ligand, denoted L, was functionalized with two TEMPO moieties. The Zn 2+ , Mn 2+ and Co 2+ complexes were isolated and structurally characterized, showing a pentacoordinated metal center, with two exogenous chloride ligands. All exhibit the typical 3-line pattern of nitroxide radicals in their EPR spectrum. The magnetic interaction between the metal and the nitroxide moieties is negligible, as demonstrated by SQUID magnetometry. Both the ligand and complexes exhibit a reversible oxidation wave at 0.30-0.35 V vs. Fc + /Fc, which corresponds to the simultaneous oxidation of both TEMPO groups into oxoammonium species. This is verified by a quenching of the nitroxide lines in the EPR spectrum during controlled potential electrolysis, as well as the appearance of shoulders around 450-500 nm in UV-Vis spectroscopy. DFT calculations support a ligandcentered oxidation, and the high spin configuration of the complexes.
SN - 0020-1693
SN - 0020-1693
ER -