Synthesis and structural studies of complexes of Cu, Co, Ni and Zn with isonicotinic acid hydrazide and isonicotinic acid (1-naphthylmethylene)hydrazide

Eight new complexes of Cu(II), Co(II), Ni(II) and Zn(II) with isonicotinic acid hydrazide (isoniazid, (INH)) and isonicotinic acid (1-naphthyl-methylene)hydrazide (INNMH), having the formula of the type [M(INH)(ac)(2))] or [M(INNMH)(ac)(2)] (M = Co(II), Ni(II) and Zn(II)) and [Cu(INH)(ac)(2)](2), [Cu(INNMH)(ac)(2)](2), were synthesized and characterized. All complexes were characterized based on elemental analyses, and IR, UV-VIS-NIR and EPR spectroscopy, as well as by thermal analysis and determination of their molar conductivity and magnetic moments. The structure of INNMH was established by single crystal X-ray analysis. In all complexes, both ligands were coordinated to the metal via N and O. The complexes of Cu (II) were dimeric, with four bridges between acetate ions and Cu(II).