Synthesis, structural characterization and electrochemical studies of an ionic cobalt complex derived from a tridentate hydrazone Schiff base and azide ligands

The first Co(III)/Co(III) ionic complex with hydrazone and azide ligands, [Co(L)2]+[Co(L)(N3)3]−∙ CH3OH, was structurally and electrochemically characterized, where HL = N′-[(1E)-1-pyridin-2-ylethylidene]-2-furohydrazide. In the cation [Co(L)2]+ two furanhydrazone, each of them with the three donor atoms, constitute a meridional arrangement around the cobalt atom. The coordination polyhedra are a CoO2N4 distorted octahedron for cation and a CoON5 distorted octahedron for anion. Cyclic voltammetric experiments of the [Co(L)2]+[Co(L)(N3)3]− in DMSO reveal reduction of the L ligand at − 1.56 V and two reduction potentials at − 0.81 and − 1.28 V for two different Co(III).