Synthesis, structural and magnetic properties of high nuclearity self-assembled cluster complexes
Thesis (M.Sc.)--Memorial University of Newfoundland, 2001. Chemistry Bibliography: leaves 103-113. This thesis describes synthesis, structural and magnetic properties of high nuclearity cluster complexes self assembled from polydentate alkoxo-diazine ligands. In Chapter 1. clusters and self-assembly...
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ftmemorialunivdc:oai:collections.mun.ca:theses3/148078 2023-05-15T17:23:32+02:00 Synthesis, structural and magnetic properties of high nuclearity self-assembled cluster complexes Zhao, Liang, 1969- Memorial University of Newfoundland. Dept. of Chemistry 2001. xii, 113 leaves : ill. Image/jpg; Application/pdf http://collections.mun.ca/cdm/ref/collection/theses3/id/148078 eng eng Electronic Theses and Dissertations (10.93 MB) -- http://collections.mun.ca/PDFs/theses/Zhao_Liang.pdf a1539360 http://collections.mun.ca/cdm/ref/collection/theses3/id/148078 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. Paper copy kept in the Centre for Newfoundland Studies, Memorial University Libraries Complex ions Antiferromagnetism Text Electronic thesis or dissertation 2001 ftmemorialunivdc 2015-08-06T19:20:21Z Thesis (M.Sc.)--Memorial University of Newfoundland, 2001. Chemistry Bibliography: leaves 103-113. This thesis describes synthesis, structural and magnetic properties of high nuclearity cluster complexes self assembled from polydentate alkoxo-diazine ligands. In Chapter 1. clusters and self-assembly have been briefly reviewed. In Chapter 2. synthesis, characterization. X-ray structures and the magnetic properties of three trinuclear copperf II) complexes are described. These compounds exhibit moderate to strong antiferromagnetic coupling as a result of superexchange via the N-N linkages. The magnetic properties are explained on the basis of large rotational angles of the copper magnetic planes about the diazine bridges. In Chapter 3. four predominantly square grid M4(ji-0)4 (M = Cu(II). Ni(II) and Co(II)) complexes and a rectangular Mru(N-N):0: grid complex are synthesized and structurally characterized by X-ray techniques. The square [2*2] copper(II) cluster exhibits intramolecular ferromagnetic spin exchange, associated with the orthogonal alkoxide bridging arrangement and the close proximity of the copper centers. Both the Ni4(|i-0)4 and Co4(ja-0)4 clusters are antiferromagnetically coupled due to the large M-O-M angles and for the rectangular Mru complex the exchange is dominated by antiferromagnetic coupling via the N-N bridge. Chapter 4 describes the ligand paoh. which has two widely separated tridentate (N:0) terminal coordination pockets, and uncoupled square [2*2] Fe(II)4 grid complex. Replacement of the NH: groups with 2-pyridyl residues gives the ligand dpkoh with the additional coordination capacity of an exo-N4 coordination pocket, leading to an octanuclear metallacyclic cluster complex [Ni8(dpkoh-2H)4(H20)8](Cl04)8-4H20, in which eight nickel(II) centers are bridged just by the diazine N-N single bond. Substantial antiferromagnetic coupling exists between the nickel(II) ions throughout the metallacycle. In Chapter 5. The synthesis, structural characterization and magnetism studies of [3*3] Mn(ll) and CutII) nanonuclear square grid complexes are described. The Mn(II)o systems exhibit intramolecular antiferromagnetic coupling, while for the Cu(II)q complexes ferromagnetic exchange is observed with an S = 7/2 ground state. The aggregation of nine octahedral Mn(II) and Cu(II) centers (fifty four coordination positions) into an alkoxo-bridged. portcullis-like [3*3] grid by six heptadentate 2poap ligands (fifty four donor positions) is a unique example of a self assembly process. Thesis Newfoundland studies University of Newfoundland Memorial University of Newfoundland: Digital Archives Initiative (DAI) |
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Memorial University of Newfoundland: Digital Archives Initiative (DAI) |
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ftmemorialunivdc |
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English |
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Complex ions Antiferromagnetism |
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Complex ions Antiferromagnetism Zhao, Liang, 1969- Synthesis, structural and magnetic properties of high nuclearity self-assembled cluster complexes |
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Complex ions Antiferromagnetism |
description |
Thesis (M.Sc.)--Memorial University of Newfoundland, 2001. Chemistry Bibliography: leaves 103-113. This thesis describes synthesis, structural and magnetic properties of high nuclearity cluster complexes self assembled from polydentate alkoxo-diazine ligands. In Chapter 1. clusters and self-assembly have been briefly reviewed. In Chapter 2. synthesis, characterization. X-ray structures and the magnetic properties of three trinuclear copperf II) complexes are described. These compounds exhibit moderate to strong antiferromagnetic coupling as a result of superexchange via the N-N linkages. The magnetic properties are explained on the basis of large rotational angles of the copper magnetic planes about the diazine bridges. In Chapter 3. four predominantly square grid M4(ji-0)4 (M = Cu(II). Ni(II) and Co(II)) complexes and a rectangular Mru(N-N):0: grid complex are synthesized and structurally characterized by X-ray techniques. The square [2*2] copper(II) cluster exhibits intramolecular ferromagnetic spin exchange, associated with the orthogonal alkoxide bridging arrangement and the close proximity of the copper centers. Both the Ni4(|i-0)4 and Co4(ja-0)4 clusters are antiferromagnetically coupled due to the large M-O-M angles and for the rectangular Mru complex the exchange is dominated by antiferromagnetic coupling via the N-N bridge. Chapter 4 describes the ligand paoh. which has two widely separated tridentate (N:0) terminal coordination pockets, and uncoupled square [2*2] Fe(II)4 grid complex. Replacement of the NH: groups with 2-pyridyl residues gives the ligand dpkoh with the additional coordination capacity of an exo-N4 coordination pocket, leading to an octanuclear metallacyclic cluster complex [Ni8(dpkoh-2H)4(H20)8](Cl04)8-4H20, in which eight nickel(II) centers are bridged just by the diazine N-N single bond. Substantial antiferromagnetic coupling exists between the nickel(II) ions throughout the metallacycle. In Chapter 5. The synthesis, structural characterization and magnetism studies of [3*3] Mn(ll) and CutII) nanonuclear square grid complexes are described. The Mn(II)o systems exhibit intramolecular antiferromagnetic coupling, while for the Cu(II)q complexes ferromagnetic exchange is observed with an S = 7/2 ground state. The aggregation of nine octahedral Mn(II) and Cu(II) centers (fifty four coordination positions) into an alkoxo-bridged. portcullis-like [3*3] grid by six heptadentate 2poap ligands (fifty four donor positions) is a unique example of a self assembly process. |
author2 |
Memorial University of Newfoundland. Dept. of Chemistry |
format |
Thesis |
author |
Zhao, Liang, 1969- |
author_facet |
Zhao, Liang, 1969- |
author_sort |
Zhao, Liang, 1969- |
title |
Synthesis, structural and magnetic properties of high nuclearity self-assembled cluster complexes |
title_short |
Synthesis, structural and magnetic properties of high nuclearity self-assembled cluster complexes |
title_full |
Synthesis, structural and magnetic properties of high nuclearity self-assembled cluster complexes |
title_fullStr |
Synthesis, structural and magnetic properties of high nuclearity self-assembled cluster complexes |
title_full_unstemmed |
Synthesis, structural and magnetic properties of high nuclearity self-assembled cluster complexes |
title_sort |
synthesis, structural and magnetic properties of high nuclearity self-assembled cluster complexes |
publishDate |
2001 |
url |
http://collections.mun.ca/cdm/ref/collection/theses3/id/148078 |
genre |
Newfoundland studies University of Newfoundland |
genre_facet |
Newfoundland studies University of Newfoundland |
op_source |
Paper copy kept in the Centre for Newfoundland Studies, Memorial University Libraries |
op_relation |
Electronic Theses and Dissertations (10.93 MB) -- http://collections.mun.ca/PDFs/theses/Zhao_Liang.pdf a1539360 http://collections.mun.ca/cdm/ref/collection/theses3/id/148078 |
op_rights |
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. |
_version_ |
1766113151509594112 |