Coordination complexes of hexadentate phthalazine hydrazone ligands

Wen, Tao (1988) Coordination complexes of hexadentate phthalazine hydrazone ligands. Masters thesis, Memorial University of Newfoundland.

[img] [English] PDF (Migrated (PDF/A Conversion) from original format: (application/pdf)) - Accepted Version
Available under License - The author retains copyright ownership and moral rights in this thesis. Neither the thesis nor substantial extracts from it may be printed or otherwise reproduced without the author's permission.

Download (42MB)
  • [img] [English] PDF - Accepted Version
    Available under License - The author retains copyright ownership and moral rights in this thesis. Neither the thesis nor substantial extracts from it may be printed or otherwise reproduced without the author's permission.
    (Original Version)

Abstract

The cobalt(II) and nickel(II) coordination complexes of three potentially hexadentate phthalazine hydrazone ligands, obtained by reacting 1,4-dihydrazinophthalazine ( DHPH ) with an appropriate aldehyde or ketone, have been investigated, in which the variable terminal donor substituents include β-methyl pyridine (PMP), pyridine (PPA) and N-methyl imidazole (PMI) groups. Studies on the analytical, -- [special characters omitted] -- spectral, X-ray, and magnetic data of the complexes reveal that the ligands are able to form double μ-bridged bimetallic complexes, in which two pseudo-octahedral metal centers are brought into close proximity by a common phthalazine diazine bridge as well as by the second either anionic [ binuclear 2:1 ( metal:ligand ) species ] or another diazine bridge [ binuclear 1:1 derivatives ]. In the binuclear 2:1 complexes three in-plane coordination sites of the pseudo-octahedral metal center are occupied by ligand nitrogen donors and the rest of the sites involve coordinated anions and water/solvent molecules. Two binuclear 2:1 chloride complexes of the ligand PMP, [Co₂(PMP)Cl(H₂O)₄]Cl₃4H₂O and [Ni₂(PMP)Cl(H₂O)₄]Cl₃4.5H₂O, have been characterized by single crystal X-ray diffraction. For the 1:1 compounds the six coordination sites are all occupied by the nitrogen atoms from two ligands. All the complexes exhibit very intense metal-to-ligand charge transfer absorption ( ε > 9200 Lmol⁻¹cm⁻¹ ) in the visible region ( 19000 - 21000 cm⁻¹ ). Variable-temperature magnetic susceptibility measurements on some complexes indicate antiferromagnetic exchange between the metal ion centers.

Item Type: Thesis (Masters)
URI: http://research.library.mun.ca/id/eprint/7970
Item ID: 7970
Additional Information: Bibliography: leaves 129-133.
Department(s): Science, Faculty of > Chemistry
Date: 1988
Date Type: Submission
Library of Congress Subject Heading: Metalloenzymes; Ligands

Actions (login required)

View Item View Item

Downloads

Downloads per month over the past year

View more statistics