Dinuclear first-row transition metal complexes with a naphthyridine-based dinucleating ligand.

A series of dinuclear and tetranuclear first-row transition metal complexes were synthesized with the dinucleating ligand 2,7-bis(di(2-pyridyl)fluoromethyl)-1,8-naphthyridine (DPFN). The coordination pocket and rigidity of the DPFN ligand enforces pseudo-octahedral geometries about the metal centers that contain chloro, hydroxo, and aqua bridging ligands forming a "diamond" shaped configuration with metal-metal distances varying from 2.7826(5) to 3.2410(11) Å. Each metal center in the dinuclear complexes has an additional open coordination site that accommodates terminal ligands in a syn geometry of particular interest in catalyst design. The complexes are characterized by electronic spectroscopy, electrochemistry and potentiometric titration methods.