Similarly, the Co (II) ion forms a tetradentate complex (Figure ) with a Schiff base ligand by coordinating with four donor atoms from the ligand. Typically, two nitrogen atoms from the azomethine group (formed during Schiff base condensation) and two oxygen atoms from phenolic groups serve as the donor atoms. This arrangement allows the ligand to "wrap around" the metal ion, resulting in a stable complex with a coordination number of four. This configuration is often observed in a square planar geometry .