Synthesis and Characterization of A New Schiff Base Ligand Containing Dinitrogen and Sulfur Atoms and Its Nickel(II) Complex

Schiff base ligands containing an azomethine group (–CH=N–) are considered as ‘privileged ligands’ because of their capability to stabilize different metals in various oxidation states. Such complexes have been extensively studied due to synthetic flexibility, selectivity and sensitivity towards a variety of metal ions [1]. Schiff base ligands with sulfur and nitrogen donor atoms in their structures, act as good chelating agents for the transition metal ions because of the presence of both hard nitrogen and soft sulfur donor atoms in the backbones of these ligands. These ligands readily coordinate with a wide range of transition metal ions yielding stable and intensely colored metal complexes [2]. In this work, a new tridentate Schiff base ligand was formed by the condensation of cysteamine and 2-pyridinecarboxaldehyde in methanol and 1:1 molar ratio. In order to synthesize of Schiff base complex a solution of Ni(OAc)2.4H2O in methanol was added dropwise to a solution of Schiff base ligand in 1:1 stoichiometry. The mixture was heated with stirring on a water bath at 62 °C for 8 hours. The products were characterized by FT-IR, 1H NMR, UV-Vis spectroscopies, elemental analysis, and conductometry.