New Spin-Transition-Like Copper(II)−Nitroxide Species

New Spin-Transition-Like Copper(II)−Nitroxide Species Full article

Journal

Inorganic Chemistry
ISSN: 0020-1669 , E-ISSN: 1520-510X

Output data

Year: 2007, Volume: 46, Number: 18, Pages: 7545-7552 Pages count : 8 DOI: 10.1021/ic700851x

Authors

Hirel Catherine ¹ , Li Licun ¹ , Brough Peter ¹ , Vostrikova Kira ² , Pécaut Jacques ¹ , Mehdaoui Boubker ³ , Bernard Maxime ³ , Turek Philippe ³ , Rey Paul ¹

Affiliations

1	CEA-Grenoble, Département de Recherche Fondamentale sur la Matière Condensée, Service de Chimie Inorganique et Biologique (UMR-E3, CEA-UJF), 17 rue des Martyrs F38054 Grenoble Cedex 09, France
2	Laboratory of Cluster Chemistry and Supramolecular Assemblies, Institute of Inorganic Chemistry, 3 Lavrentiev. Avenue, 630090 Novosibirsk, Russia
3	Institut de Chimie (UMR 7177, CNRS-ULP), 1 rue Blaise Pascal, BP 296 R8, 67008 Strasbourg Cedex, France

Novel copper(II)-nitroxide complexes exhibiting a spin-transition like behavior have been prepared and characterized. They include meso, chiral and racemic 2-(3-pyridyl)-nitronyl nitroxides differently substituted in positions 4 and/or 5 by ethyl groups, and pyrimidyl nitroxides. Depending on the stoichiometry of the reaction, tetranuclear and binuclear complexes were obtained whose structures are cyclic. The tetranuclear species, which include two intracyclic and two exocyclic metal sites, are similar to the previously reported complex of the tetramethylated analogue, while the binuclear complexes involve only endocyclic metal ions and have uncoordinated N-oxyl groups. The tetranuclear complexes exist as two isomers depending on the temperature of crystallization: at room temperature, N-oxyl ligand coordination is axial-axial while it is axial-equatorial at low temperature. Unexpectedly, this isomerism concerns N-oxyl bonding to the exocyclic metal centers for the derivatives of 4,5-diethyl substituted ligands while it involves the endocyclic metal site in the complex of the mono-ethylated ligand which converts reversibly from a high-spin state to a low-spin state as observed for the complex of the tetramethylated ligand. Binuclear complexes are diamagnetic at room temperature but convert to a paramagnetic state on warming (90-110 °C); the transition is irreversible and sharp.

Hirel C. , Li L. , Brough P. , Vostrikova K. , Pécaut J. , Mehdaoui B. , Bernard M. , Turek P. , Rey P.
New Spin-Transition-Like Copper(II)−Nitroxide Species
Inorganic Chemistry. 2007. V.46. N18. P.7545-7552. DOI: 10.1021/ic700851x WOS Scopus РИНЦ OpenAlex

Web of science:	WOS:000248984500045
Scopus:	2-s2.0-34548652354
Elibrary:	13540177
OpenAlex:	W2008818909

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