An orthogonal ferromagnetically coupled tetracopper(II) [2×2] homoleptic grid supported by four μ-alkoxido bridges

• Published in: Polyhedron 2012-10, Vol.47 (1), p.24-29
• Main Authors: Jana, Atanu, Konar, Saugata, Das, Kinsuk, Ray, Sangita, Golen, James A., Rheingold, Arnold L., Ribas, Joan, El Fallah, Mohamed Salah, Kar, Susanta Kumar
• Format: Article
• Language: English
• Subjects: Crystal structure; Ferromagnetic coupling; Polydentate hydrazone type ligand; Tetrcopper(II) [2×2] homoleptic grid; μ-O4 Alkoxido bridges
• ISSN: 0277-5387
• DOI: 10.1016/j.poly.2012.08.023

Synthesis, crystal structures, magnetic behavior and electronic spectra of a tetranuclear Cu4(II) (2×2) grid derived from a ditopic ligand N-[amino(pyridin-2-yl)methylidene]-1-(4,6-dimethylpyrimidin-2-yl)-5-methyl-1H-pyrazole-3-carbohydrazonic acid, PymPzOAP. [Display omitted] ► Crystal structure of tetranuclear Cu4(II) (2×2) grid. ► Infrared spectroscopy, electronic spectra. ► Magnetic properties. A pyrimidyl-pyrazole based ditopic ligand N-[amino(pyridin-2-yl)methylidene]-1-(4,6-dimethylpyrimidin-2-yl)-5-methyl-1H-pyrazole-3-carbohydrazonic acid, PymPzOAP prepared by the reaction between pyrimidyl pyrazole 3-carbohydrazide and methyl ester of iminopicolinic acid, reacts with Cu(NO3)2·6H2O to form a self-assembled, ferromagnetically coupled alkoxide bridged tetranuclear homoleptic Cu(II)4 [2×2] grid complex [Cu4(PymPzOAP)4](NO3)4 (1). The complex has a central Cu4(μ-OR)4 core involving four ligand molecules. All the Cu(II) centers have N4O2 coordination environment with distorted octahedral geometry. Intramolecular ferromagnetic interaction between Cu(II) centers (J=4.94, S=4/2) is the signature of the molecule.