Synthesis and spectroscopic studies on 3-isonicotinamidorhodanine complexes of some bivalent metal ions

Summary 3-Isonicotinamido-rhodanine (HINRd) reacts with metal ions to yield complexes of the types M(INRd)OH·nH₂O (where M=Co^II, Ni^II, Zn^II or Cd^II and n=1 or 2), Cu(HINRd)X·2H₂O (where X=Cl or Br), Pd(HINRd)Cl₂ and Cd(HINRd)X₂·H₂O (where X=Cl or Br), depending on the metal salt used and the reaction conditions. The metal complexes have been characterized by elemental analysis, molar conductivities, molecular weights, magnetic susceptibility, visible, and i.r. studies. The i.r. spectra show that HINRd binds in a bidentate or monodentate manner. The spectral and magnetic studies suggest a tetrahedral arrangement for Co^II, octahedral for Ni^II and square-planar for Pd^II. HINRd behaves as a reducing agent towards Cu^II chloride or bromide forming diamagnetic Cu^I complexes.