Syntheses, crystal structures, and magnetic properties of four one-dimensional metal-nitroxide coordination polymers linked by flexible dicarboxylate anions

摘要

Four new one-dimensional coordination polymers [Co(IM4Py)2(adi)(H2O)2])n, [Zn(IM4Py)2(adi)(H2O)2]_n [Cd(IM4Py)2(adi)(H2O)2]_n, and [Ni(IM4Py)2(glu)(H2O)2]? (IM4Py = 2-(4'-pyridyl)-4,4,5,5-tetramethylimidazoline-l-oxy1, adi = adipate anion and glu = glutarate anion) were synthesized and structurally characterized. The single-crystal X-ray analyses indicate that all four complexes crystallize in neutral one-dimensional chains in which the nitroxide-metal-nitroxide units are bridged by the flexible dicarboxylate anions. The adipate anions adopt the anti/gauche/anti and anti/ anti/anti conformations in the Co(II), Zn(II), and Cd(II) complexes, while the glutarate anions only possess the anti/ anti conformation in the Ni(II) complex. The magnetic properties of the Co(II) and Ni(II) complexes show the occurrence of weak antiferromagnetic interactions between the metal atoms and the nitroxide radicals.