FeII and CoII Complexes with Click-Derived Tripodal Ligands: Influence of the Peripheral Substituents on Geometric Structures and Magnetic Properties

摘要

Tuning of the geometric and electronic properties of a transition metal center through manipulation of the secondary coordination sphere is an important topic in contemporary chemistry. In this contribution we present mononuclear iron(II) and cobalt(II) complexes that contain click-derived tripodal ligands with peripheral phenyl substituents on the backbone. A comparison of the complexes presented here with those of previously reported complexes shows that the substituents at the ligand backbone dictate the first coordination environment at the metal center, and hence, its geometric structure. The substituents also have a decisive influence on the spin state of the metal centers. Apart from synthesis and characterization, single-crystal X-ray diffraction studies and magnetometric measurements have been performed to investigate the properties of these complexes. We show here how the modification of the peripheral substituents in these increasingly popular tripodal ligands can influence the geometric and electronic structures of the reported metal complexes. These results are likely to have an impact in the field of magnetism related to such complexes, as well as in the study of spin state dependent reactivity in related iron(II) and cobalt(II) complexes.