New Cu(II), Co(II), and Ni(II) complexes with thieno[2,3-b]pyridine and 2-methylthieno[2,3-b]pyridine as ligands: Synthesis and crystal structures
AbstractAlthough thienopyridines attract attention because of their biological activities, they have not been used as ligands in coordination compounds. Thieno[2,3-b]pyridine was prepared by known procedures; by reduction of 2-nitrothiophene, and reaction of the resulting 2-thienyl ammonium salt with malondialdehyde tetramethylacetal in the presence of zinc chloride. The same procedure was used for the preparation of a new derivative, 2-methylthieno[2,3-b]pyridine, starting from 2-methyl-5-nitrothiophene. The thienopyridines were used in the synthesis of coordination compounds. Chlorides, isothiocyanates, acetates, and chloroacetates of copper(II), nickel(II), or cobalt(II) were used as starting salts. The prepared complexes were characterized by elemental analysis and FT IR. Structures of the four complexes were determined by single-crystal X-ray diffraction analysis.