Synthesis, Characterization and Spectral Studies of Triethanolamine Complexes of Metal Saccharinates. Crystal Structures of [Co(tea)2](sac)2 and [Cu2(μ-Tea)2(sac)2]·2 (CH3OH)

Abstract

The novel transition metal saccharinate complexes of triethanolamine (TEA) have been synthesized and characterized by elemental analyses, magnetic moments, UV-Vis and IR spectra. Mn(II), Co(II), Ni(II), Zn(II), Cd(II) and Hg(II) forro mononuclear complexes of [M(TEA)<inf>2</inf>](SAC)<inf>2</inf>, where SAC is the saccharinate ion, while the Cu(II) complex is dimeric. The TEA ligand acts asa tridentate N,O,O′-donor ligand and one ethanol group is not involved in coordination. The SAC ion does not coordinate to the metal ions and is present as the counter-ion in the Mn(II), Co(II), Ni(II), Zn(II), Cd(II) and Hg(II) complexes, but coordinates to the Cu(II) ion asa monodentate ligand. The crystal structures of the [Co(TEA)<inf>2</inf>](SAC)<inf>2</inf> and [Cu<inf>2</inf>(μ-TEA)<inf>2</inf>(SAC)<inf>2</inf>]·2 (CH<inf>3</inf>OH) complexes were determined by single crystal x-ray diffraction. The Co(II) ion has a distorted octahedral coordination by two TEA ligands. The Cu(II) complex crystallizes as a dimethanol solvate and has doubly alkoxo-bridged centrosymmetric dimeric molecules involving two tridentate triethanolaminate (deprotonated TEA) and two monodentate SAC ligands. The geometry of each Cu(II) ion is a distorted square pyramid. Both crystal structures are stabilized by hydrogen bonds to form a three-dimensional network.