Synthesis and Characterization of Transition Metal Complexes with Carboxamide Ligands and Nanostructures for Catalytic and Antibacterial Activites Application

Kiani, Mahsa | 2021

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  1. Type of Document: Ph.D. Dissertation
  2. Language: Farsi
  3. Document No: 53687 (03)
  4. University: Sharif University of Technology
  5. Department: Chemistry
  6. Advisor(s): Bagherzadeh, Mojtaba
  7. Abstract:
  8. Carboxamide ligands have been part of the growing research in the field of coordination chemistry of transition metal complexes. The solvent used in the classical method of synthesis of these compounds is pyridine, a solvent which is extremely toxic. In this project, we have developed a new method of synthesis using ionic liquids as the reaction media and have prepared Hqcq (1), Htp(2) under optimum conditions for Pd(II) and Pt(II) complexes of Hqcq and Co(II), Cu(II), Zn(II), Cd(II) and Hg(II) complexes of Htp with the formula:[Pd(qcq)(OAc)] (1a), [Pt(qcq)(Cl)] (1b), [Co(Htp)2(H2O)2].C2H5OH (2a), Co3O4 (2b), [Cu(tp)2(H2O)].CHCl3 (2c), CuO (2d), [Zn(tp)2(H2O)2] (2e), [Cd(tp)2(H2O)2].CH3OH (2f) and [Hg(tp)2(S)2] (2g) have also been synthesized and characterized by UV-Vis, FT-IR, 1H-NMR and elemental analysis and antibacterial activity of the synthesized compounds has also been investigated.The structure of (1a), (1b), (2a), (2c), (2e) and (2f) complexes and Hqcq (1) ligand were determined by X-ray crystallography.The mono-ionic qcq- is a tridentate unsymmetrical ligand furnishing an N3 set. Such that two N atom of the quinoline and one amide N atom occupies the equatorial positions. Acetate ion act as mono dentate ligand in (1a) completing the distorted square-planer structure. The structure of the platinum complex of this ligand (1b) is also a distorted square-planer structure, which is identified by the structure of the Hqcq ligand.Complexes (2a), (2e) and (2f) show a distorted octahedral structure and for complex (2c) shows a distorted square-planer structure around the central ion.The electrochemical behavior of the ligands and (1a), (2a) and (2c) complexes shows that the reduction processes corresponding to the quinolone and pyridine ring occurs at more positive potentials in complexes relative to the free ligands, as expected for an anionic ligand after coordination to metals.Cobalt (II) and Copper(II) complexes from Htp were employed as a novel precursor in thermal decomposition for preparation of Co3O4 and CuO nanoparticles. The nanoparticles were characterized by X-ray diffraction (XRD), scanning electron microscopy (FE-SEM), infrared (IR) spectroscopy and ultraviolet–visible (UV–Vis) spectroscopy.In the applications section, (1a), (2a) complexes and (2b) nanoparticles were used for the Mizuroki-Heck coupling reaction, and in general, aryl iodide and aryl bromide are much more effective than aryl chloride in the heck reaction. These systems are very efficient and effective for the coupling reaction of aryl halides with olefins.(2a) Complexes and (2b) nanoparticles were then used for the epoxidation reaction of olefins, the results of which show that these compounds are catalysts of efficiency in the epoxidation reaction of olefins with high conversion percentage and high selectivity.In the third part, the (2c) complex and (2d) nanoparticles were used for the catalytic reaction of azide-alkyne cycloadittion, which are easy to prepare, mild reaction conditions, high reaction efficiency of products, short reaction time, no by-products, high selectivity and inexpensive system were used as useful catalytic systems for azide-alkyne cycloadittion.In this work, the (1) and (2) ligands and (1a), (1b), (2c) and (2d) complexes were also screened for their in vitro antibacterial activity against positive-gram and negative-gram bacteria.In the fourth part, a bidentate ligand, Htp (2), to investigate the possibility of the application of these new ligands as sensors for detection of biologically important ions, the absorption and florescence spectra of this ligand was obtained. The spectral properties of this ligand, i.e. Htp were investigated in the absence and presence of different metal ions. The results show that these ligands can be used as a turn-on fluorescent sensor for detection of Zn+2 ions with high selectivity and sensitivity compared to other metal.In the final part of this work, Pt-CdS / Ag3PO4 / Chitosan nanocomposite was synthesized, identified by FT-IR, XRD and FESEM analyzes and then used to evaluate the antibacterial activity under visible light
  9. Keywords:
  10. Antibacterial Activity ; Nanocomposite ; Green Chemistry ; Ionic Liquids ; Visible Light ; Carboxamides ; Catalytic Activity ; Crystalline Structure

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