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Binuclear transition metal complexes of face-to-face compartmental bis(cyclidene) ligands /Hoshino, Naomi, January 1984 (has links)
No description available.
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The synthesis, characterization and dioxygen affinity of totally synthetic transition metal cyclidene complexes supported on polymers /Novotnak, George Clarence January 1987 (has links)
No description available.
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Low-spin transition metal complexes of a flexible bidentate phosphorus ligand and a flexible tridentate phosphorus ligand /Cloyd, John Charles January 1970 (has links)
No description available.
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Study of reactions of transition metal alkyl, alkenyl, and alkynyl complexes with tetracyanoethylene /Su, Sophia Ruei January 1971 (has links)
No description available.
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Spectrophotometric study on chelates of transition metals with nicotinylhydroxamic acid, cinnamohydroxamic and potassium 2-furohydroxamateRowland, Ronald Gene. January 1965 (has links)
Call number: LD2668 .T4 1965 R883 / Master of Science
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Luminescent platinum(II), copper(I), silver(I) and zinc(II) complexes with functional pyridyl and arylacetylide ligands: structures, spectroscopic properties and applicationsLin, Yongyue, 林勇躍 January 2001 (has links)
published_or_final_version / Chemistry / Doctoral / Doctor of Philosophy
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Syntheses, characterization and emission studies of luminescent homo-and heterometallic clusters based on coinage metal alkynyl andchalcogenide coreLo, Wing-yin., 盧詠妍. January 2004 (has links)
published_or_final_version / Chemistry / Doctoral / Doctor of Philosophy
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Two dimensional transition metal dichalcogenides grown by chemical vapor depositionTsang, Ka-yi, 曾家懿 January 2014 (has links)
An atomically thin film of semiconducting transition metal dichalcogenides (TMDCs) is emerging as a class of key materials in chemistry and physics due to their remarkable chemical and electronic properties. The TMDCs are layered materials with weak out-of-plane van der Waals (vdW) interaction and strong in-plane covalent bonding enabling scalable exfoliation into two-dimensional (2D) layers of atomic thickness. The growth techniques to prepare these 2D TMDC materials in high yield and large scale with high crystallinity have attracted intensive attention recently because of the new properties and potentials in nano-elctronic, optoelectronic, spintronic and valleytronic applications.
In this thesis, I develop methods for the chemical synthesis of 2D TMDCs films. The relevant growth mechanism and material characteristics of these films are also investigated. Molybdenum disulfide (MoS2) is synthesized by using molybdenum trioxide (MoO3) and sulfur (S) powder as the precursor. The films are formed on substrate pre-treated with reduced graphene oxide as the catalyst. However, this method cannot be extended to other TMDC materials such as molybdenum diselenide (MoSe2) and tungsten diselenide (WSe2) because reduced graphene oxide (rGO) reacts with selenium to form alloy materials rather than TMDC films. At the same time, the conversion of MoO3 to MoSe2 or that of tungsten trioxide (WO3) to WSe2 without the assistance of hydrogen in the chemical reaction is not thermodynamically feasible because the oxygen in the metal oxide cannot be replaced by selenium due to lower reactivity of the latter. On the other hand, I demonstrate that MoSe2 film can be synthesized directly by using MoSe2 and Se powder. Furthermore, the method of sulfurization or selenization of pre-deposited metal film can be promising due to precise thickness/size controls. Finally, some perspectives on the engineering challenges and fabrication methods of this family of materials will be given. / published_or_final_version / Physics / Master / Master of Philosophy
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Structural studies of disordered molybdatesFawcett, Ian D. January 1996 (has links)
No description available.
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Structural, physical and biological studies of transition metal Schiff base complexes.De Ponte, Justine C. 01 November 2013 (has links)
The aims of this work were first to synthesize and fully characterize compounds that may
function as bleomycin analogues and, second, to test their anticancer activity in vitro. Three
novel tetradentate O,N,N,O Schiff base ligands, H₃L¹, H₂L³ and H₂L³ were synthesized by
condensation of three different 1,3-diaminoalkane bridging units with two equivalents of
(2,4-dihydroxy–phenyl)-(phenyl)methanone. These ligands contain two neutral imine
nitrogen donors and two anionic phenolate oxygen donors for the coordination of metal ions.
The choice of ligand was guided by the fact that Cu(II) bleomycin analogues with ligands
employing O,N,N,O donor atom sets are able to cleave double-stranded DNA via oxygen
radical formation. Using these ligands, six novel metal complexes of copper(II), nickel(II)
and zinc(II) were synthesized and fully characterised. Two novel ligand crystal structures and
six novel metal complex crystal structures are reported in this work.
The X-ray structures of the two structurally characterized nickel(II) complexes [Ni(L²)] and
[Ni(L³)] adopted the same nominally square planar coordination geometry, with the metal ion
bound by the pairs of imine nitrogen and ortho-phenolic oxygen atoms of the ligand’s
tetradentate donor atom set. The Ni–N and Ni–O distances averaged 1.892(3) Å and
1.845(2) Å, respectively. However, when reacted with Cu(II) and Zn(II), the ligands favored
the formation of multinuclear complexes as a result of metal ion bridging by ionized oxygen
donor atoms (either the phenolic oxygen atoms or an alkoxide oxygen atom of the 2-hydroxy
substituted alkane bridge in the case of H₃L¹) of the polyfunctional ligands. For the di- and
trinuclear copper(II) complexes, the mean Cu–N and Cu–O distances averaged 1.953(3) Å
and 2.082(3) Å, respectively. For the dinuclear zinc(II) complex, the mean Zn–N and Zn–O
distances averaged 2.074(3) Å and 2.042(3) Å, respectively.
Electron spin resonance (ESR) measurements on the paramagnetic trinuclear copper(II)
complexes confirmed that the trinuclear solid state structures remain intact in fluid solution
(DMF) and that two of the three copper(II) ions are antiferromagnetically coupled, leaving
the third as an S = ½ center with a hyperfine coupling constant to the I = 3/2 Cu nucleus of
14.80 G. Super-hyperfine coupling (15.13 G) to two N atoms was also evident, consistent with one of the terminal copper(II) centers (O,N,N,O donor atom set) being the site of the unpaired spin density in the molecule.
Density functional theory (DFT) simulations were used to determine the electronic structures of the diamagnetic mononuclear nickel(II) complexes. The simulations reproduced the structures of [Ni(L²)] and [Ni(L³)] accurately with similarity coefficients for the two complexes of 0.982 and 0.990, respectively. The simulated electronic spectra (TD-DFT) of
the nickel(II) complexes showed reasonably good agreement with the experimental spectra and were useful for the assignment of the low-lying MLCT state (near 400 nm) for the complexes as well as the higher-lying π-π* transitions between 300–350 nm. All of the metal complexes and one ligand were sent to MINTEK¹ (Project AuTEK) for anticancer screening. The copper(II) complexes (bleomycin analogues capable of generating
hydroxyl radicals in vivo) showed significant cytotoxicity against the human cancer cell lines A549, DU145, HT-29, and U21. The trinuclear complexes were the most cytotoxic with mean IC₅₀ values of 6(2) and 7(1) μM for [Cu₃(L²)₂Cl₂(DMF)₂] and [Cu₃(L³)₂(H₂O)₂]Cl₂, respectively. The nickel(II) complexes [Ni(L²)] and [Ni(L³)] were comparatively inactive
with mean IC₅₀ values of >50 and 35(16) μM, respectively, consistent with the fact that they do not readily generate reactive oxygen species in a cellular environment. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2013.
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