Metal saccharinate complexes with N,N-bis(2-hydroxyethyl)ethylendiamine: Synthesis, structural, thermal decomposition and DFT studies

Abstract

New Co(III), Ni(II), Cu(II), and Zn(II) saccharinate (Sac) complexes bearing with N,N-bis(2-hydroxyethyl)ethylenediamine (N-bishydeten), namely [Co(2HN-bishydeten)2](Sac)⋅2H2O, [Ni(Sac)2(N-bishydeten)], [Cu(N-bishydeten)2](Sac)2 and [Zn(Sac)2(N-bishydeten)] were synthesized and characterized using UV–Vis, IR spectroscopy and magnetic susceptibility measurements. The crystal structures of the complexes were analysed by single crystal X-ray diffraction. Both N-bishydeten and Sac displayed coordination versality. The N-bishydeten ligands were octahedrally coordinated as two tridentate anionic ligands (2HN-bishydeten) (N, N, O-) to the Co(III) and two tridentate neutral ligands (N, N, O) to the Cu(II). The anionic Sac ligand was also located outside the coordination sphere in these complexes. However, the N-bishydeten ligand behaved as a tetradentate ligand (O, N, O, N) in the Ni(II) and Zn(II) complexes while two Sac ligands were coordinated the corresponding metals ions in a monodentate fashion, one through the N atom and the other via the carbonyl O atom. Thermal decomposition of the complexes was studied in inert atmosphere and thermal analysis data (TG and DTA) indicated multi-step decompositions of the metal complexes decomposed in a single stage. The thermal decomposition products were estimated as metal oxides. Finally, the structural properties of all complexes were investigated through quantum chemical computations. © 2024 Elsevier B.V.