Two cobalt metal-organic frameworks constructed from mixed ligands and their magnetic properties

Abstract

The reaction of the polycarboxylic acid ligand tri(2-carboxyethyl)-isocyanurate (H 3 L 1), polyazo bridged ligand 1H-3-(3-pyridyl)-5-(4-pyridyl)-1,2,4-triazole (L 2), CoCl 2 • 6H 2 O, and different organic solvents lead to the formation of two novel coordination complexes: [Co 3 (L 1) 2 (L 2) 2 (H 2 O) 4 ] n (1), [Co 3 (L 1) 2 (L 2) 2 (H 2 O) 2 ] n • 2nH 2 O (2). Two complexes were prepared under solvothermal conditions and characterized by the single-crystal X-ray diffraction, thermal analysis, element analysis, X-ray powder diffraction, and IR spectra. Single-crystal X-ray analysis reveals that complex 1 features a three-dimensional framework and 2 is a two-dimensional layer structure. Variable-temperature magnetic susceptibility measurements show that both complexes display anti-ferromagnetic interactions between adjacent Co(II) centers.

Influence of reaction temperature and stoichiometry on the coordination mode of a multidentate pyridylpyrazole ligand in Co(ii) complexes: from a 0D mononuclear structure to 3D frameworks

“…These complexes displayed antiferromagnetic interactions between the adjacent Co( ii ) centers. 36 Shao et al exploited a 2D Co( ii ) single-ion magnet, which exhibited slow magnetic relaxation under external fields. 37 Legendre et al developed a 3D paramagnetic Co( ii ) complex with the tunable bis(benzoxazol-2-yl)methanide ligand.…”