The Synthesis, Characterization, and Reactivity of Schiff Base Transition Metal Complexes

Isabella Demyan, Union College - Schenectady, NY

Abstract

Research in the Tyler Lab has been focused on determining the reaction conditions which promote full or partial hydrolysis of Schiff Base ligands while ligated to either Cu(II) or Ni(II) metal centers, and if that hydrolysis can be controlled. The following research investigates novel imine ligand synthesis and characterization, as well as metal complex formation and analysis through antibacterial studies. The ligands are synthesized by reacting two equivalents of a pyridine aldehyde (R = H, OMe, Me) with ethylenediamine in ethanol, and are characterized by ¹H NMR and IR spectroscopies. Similar reactions have been carried out in a 1:1 molar ratio with several different Cu(II) and Ni(II) salts. The Cu(II) complexes have been characterized with ¹H NMR, IR, elemental analysis, and X-Ray Crystallography. Additionally, DNA cleavage studies using gel electrophoresis were conducted on one Cu(II) complex to assess its potential as a metallonuclease. The monomer with a half-hydrolyzed ligand displayed quantitative DNA cleavage abilities, increasing in ability to cleave to single-nicked DNA, but not fully to double-nicked. Further research is being conducted in the Tyler lab on more Cu(II) and Ni(II) complexes to determine the differences in reactivity of each metal complex and the effect of the ligand backbone. Additionally, antibacterial studies will be conducted on the free ligands and metal complexes to determine possible antibacterial properties, and the effect of the metal center on the ligand reactivity.