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)eth- ylenediamine ( N-bishydeten ), namely [Co(2H N-bishydeten ) 2 ]( Sac ) & sdot; 2H 2 O, [Ni( Sac ) 2 ( N-bishydeten )], [Cu( N-bishy- deten ) 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 (2H N-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.