Tridentate NˆNˆN iron(II) and cobalt(II) complexes of ion-paired structures: Synthesis, characterization and magnetism

Two kinds of ion-paired iron and cobalt complexes ligated by 2-(benzimidazolyl)-6-(1-(arylimino)ethyl)pyridyl [iron (1a) and cobalt (1b)] or N-(pyridin-2-yl)methylene)-quinolin-8-amine (iron, 2a) were synthesized and well characterized by IR, EA and X-ray diffraction analysis. They were confirmed to be in the form of [ML2]2+[MCl4]2− or [ML2]2+2[MCl4]1− and the cations took octahedral coordinated geometry. Structure research indicated that complex 1a was in low-spin state while complex 1b was in high-spin state. Furthermore, their magnetic susceptibility measurements were performed and the complexes showed interesting magnetic properties.