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Synthesis of Azacrown Ethers N2O2 Ligands Substituted on the Ullerene and Investigation of Its Coordination Properties

Khamseh, Leila | 2009

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  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 40053 (03)
  4. University: Sharif University of Technology
  5. Department: Chemistry
  6. Advisor(s): Ghanbari, Bahram
  7. Abstract:
  8. The goal of this project was study on coordination behavior of the 14-membered macrocyclic ligand of type N2O2 aza-crown while it is attached to fullerene C60 nano-particle. For this purpose, firstly the macrocyclic ligand (Fig 3-1, L1) was synthesized and then was reacted with C60 (Fig 3-1, L2) of which the product was characterized by elemental analysis. Since the product was insoluble in any solvents, further study on its coordination chemistry was impossible. In a second procedure, the macrocyclic ligand was reacted with benzylbromide. The reaction mixture gave two macrocyclic ligands with different number of benzylic pendant groups (Fig 3-1, L3-L4). The products were separated by column chromatography and characterized by IR, NMR, UV-visible spectroscopy as well as elemental analysis. The Co(II) and Cu(II) complexes of the macrocyclic ligand incorporating two pendant benzylbromide arms were also synthesized and characterized by infrared, NMR, UV-visible spectroscopy and elemental analyses. The macrocyclic ligand having one pendant benzylbromide was reacted with C60 to give O-en-N-tn-benzyl-C60. The ligand and its Co(II) complex ([Co(O-en-N-tn-benzyl-C60]Cl2) were also characterized by characterized by infrared spectra, absorption, elemental analyses and conductometric measurements. To investigate the solution chemistry of Co(II) complex of the macroring bearing C60, the effect of methanol addition to the complex solution in DMSO has been investigated by UV-visible spectroscopy. Comparing the observations with those made for free macocyclic ligand complex of Co(II) showed that upon addition of methanol to the DMSO solution of the Co(II) and Cu(II) complexes, dramatic spectral changes were happened. The results clearly showed coordination change around the metal ion from Td to Oh. These observations were supported by subsequent increases in the molar conductance which was better for the macroring bearing C60 moiety. The role of methanol in the solution can be described in terms of its good acceptor number and it subsequently facilitate in solvation of the chloride ions.


  9. Keywords:
  10. Fullerene ; Azacrown ; Macrocycle ; Macrocyclic Ligand ; Fullerene Nano Particle ; Coordination Model

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