Synthesis of a sulfonamide-Schiff base ligand and its Cu(II), Fe(III) and Co(III) complexes

•A novel ligand based on unsymmetric substitution of ethylenediamine was synthesized.•Complexes with several metal ions were prepared.•The ligand and the complexes were structurally characterized by X-ray crystallography.•Three types of binding to metal centers were observed and compared to similar structures.

An unsymmetric ligand bearing a salicylimine side and a 2-nitrobenzenesufonamide side has been synthesized in two simple steps. Complexations with Cu(II), Fe(III) and Co(II) – which oxidizes to Co(III) once complexed – indicate that the ligand can be either bidentate or tridentate depending on the geometric preferences of the metal ion and whether the sulfonamide is deprotonated. The obtained crystal structures are also stabilized via hydrogen bonds and π–π stacking interactions.

Graphical abstractCoordination versatility is observed with a unsymmetric salicylimine-sulfonamide ligand.Figure optionsDownload full-size imageDownload as PowerPoint slide