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

Abstract

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] n (IM4Py = 2-(4′-pyridyl)-4,4,5,5-tetramethylimidazoline-1-oxyl, 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.