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-naphthylmethylene)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).