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.

Chapter 1 presents an overview of the lanthanide chemistry with cyclopentadienyl and cyclopentadienyl-free ligands. The chemistry of divalent lanthanide is also briefly reviewed. / Chapter 2 describes the preparation and characterization of a series of lanthanide(III) amides derived from the bidentate 2-pyridyl amido ligand [N(SiMe3)(2-C5H3 N-6-Me)] (L 1): [Ln(L1)3] [L1=, Ln = Yb (7), Sm (8), Dy (9)], [Ln(L 1)3(THF)] [Ln = Pr (10), Gd (11)], and [(L1)2Ln(mu-OBut) 2Li(THF)x] (x = 2, Ln = Nd (12), Sm ( 13), Eu (14); x = 1, Ln = Dy (15), Er ( 16)). / Chapter 3 describes the preparation and characterization of divalent lanthanide amides derived from L1 and the more bulky [N(SiButMe2)(2-C5H 3 N-6-Me)] (L2) ligands, namely [Ln(Ln) 2(tmeda)] (n = 1, Ln = Yb (17), Eu (20); n = 2, Ln = Yb (18)), [(L1)3YbK(THF)] (19), and [(L2)3EuK(tmeda)] ( 21). Complexes 17-21 were prepared by direction reaction of LnI2(THF)), (Ln = Eu or Yb) with the potassium salts of L 1 and L2. Attempts to synthesize the analogous Sm(II) and Dy(II) derivatives were unsuccessful. The divalent samarocene, [(C 5H3(SiMe3)2)2Sm(THF)] ( 24), was also prepared in our work. Subsequent reaction of 24 with 1,3-dicyclocarbodiimide (DCC) in THF yielded the dinuclear Sm(III) bisamidinate compound [(Cp")2Sm(NC6H11) 2CC(H11C6N)2Sm(Cp")2] ( 25). / Chapter 4 describes the preparation and characterization of divalent Sm, Eu and Yb complexes derived from the bulky dianionic [R 2Si(NC6H3Pri2-2,6) 2]2- (R = Me or Ph) ligands. Treatment of LnI2(THF)), (Ln = Sm, Eu, and Yb) with K2(Ln)(THF) x (L3 = Me2Si(NC6H3Pr i2-2,6)2, L4 = Ph2Si(NC 6H3Pri2-2,6)2) afforded the corresponding Ln(II) derivatives, [(L4)2Sm{K(OEt 2)}2] (36), [(C)2Ln {K(THF) 2}2] (n = 4, Ln = Yb (39); n = 3, Ln = Sm ( 37), Yb (40), Eu (44), and the mononuclear compound [(L4)Yb(THF)3] (38). / However, attempts to prepare divalent Nd and Dy complexes of the dianionic ligands were unsuccessful. Only the corresponding Nd(III) and Dy(III) complexes were isolated. In our studies, five lanthanide(III) complexes, namely [{K(THF) 6}Ln(L4)2] (Ln = Sm (34), Yb (41), Nd (42), Dy (43)) and [(L 3)2SmK(THF)3] (35) were isolated. / This thesis describes the synthetic and structural studies of lanthanide complexes derived from the monoanionic 2-pyridyl amido ligands [N(R)(2-C 5H3N-6-Me)]- (R = SiMe3, SiBu tMe2), the dianionic [R2Si(NC 6H3 Pri2-2,O2] 2- (R = Me or Ph) ligands, and the bis(trimethylsilyl)-cyclopentadienyl [C5H3(SiMe3)2]- ligand. / Pan, Chengling. / "February 2008." / Source: Dissertation Abstracts International, Volume: 70-03, Section: B, page: 1665. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references. / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.

Alkane elimination reaction of Hf(CH2SiMe3) 4 with a zwitterionic salt 1-Me2NHCH2CH2 -1,3-C2B10H12 has resulted in the isolation and structurally characterization of the first example of half-sandwich group 4 metallacarborane alkyls of the C2B10 system. This is also a new route to high-valent group 4 metallacarboranes. / Alkane or amine elimination reactions are also effective methods for the preparation of half-sandwich group 4 metal] acarboranes of the C 2B9 system. The Lewis base functionalized sidearm can effectively stabilize half-sandwich group 4 metallacarborane alkyls through intramolecular coordination. These novel metallacarborane alkyls undergo insertion reaction with alkyne and intramolecular hydrogen atom abstraction reactions. / High-valent group 4 half-sandwich metallacarboranes incorporating an eta 7-carboranyl ligand have been prepared and structurally characterized. The heteroatom-containing pendant sidearms on the carborane cage are both electronically and entropically necessary for the formation of such complexes. / Reaction of [(Me2NCH2CH2)C2B 10H11]Na2 with YCl3 gives eta 1:eta6-[(Me2NCH2CH2)C 2B10H11]YCl(THF)3 containing an exopolyhedral Y-Cl bond, which offers an important intermediate for the preparation of lanthanacarboranes bearing the Ln-C or Ln-X (X = heteroatoms) bonds. On the other hand, it implies that Lewis base functionalized carboranes can stabilize half-sandwich metallacarboranes via the coordination of heteroatom from the sidearm. Silylamine elimination reactions of the neutral ligand 7-Me2NHCH2CH2-7,8-C 2B9H11 with Ln[N(SiHMe2)2] 3(THF)2 are effective method for the preparation of half-sandwich lanthanacarboranes. / Reactions of alkali metal salt of these carboranes with LnCl3 in the presence of excess alkali metal afford a novel class of 13-vertex closo-metallacarboranes incorporating eta7-carboranyl ligands [{eta1:eta1:eta7-[(DCH 2CH2)RC2B10H10]Ln}{Na(solvent) x}]n. Structural studies show that the Lewis base functionalized sidearms have some effects on the coordination environments of the central metal atom, but do not change the gross structures of the 13-vertex closo-metallacarboranes. The reactivity patterns of these 13-vertex closo-metallacarboranes have been studied for the first time. / Several mono- and bisfunctional carboranes (DCH2CH2)RC 2B10H10 (R = H, DCH2CH2, D = MeO, Me2N) have been designed and successfully synthesized. They can be conveniently converted into the monoanions, the dianions and the tetraanions by treatment with suitable reagents. Their applications in organolanthanide and group 4 organometallic chemistry have been studied. / Cheung Mak-shuen. / "June 2005." / Adviser: Kevin W. P. Leung. / Source: Dissertation Abstracts International, Volume: 67-01, Section: B, page: 0258. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (p. 169-181). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract in English and Chinese. / School code: 1307.

Ren, Zhiyuan. / "March 2001." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references (p. 137-143). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.

a series of complexes of the type MLnX where M=Cu(II), Ni(II), and Cr(III), L=β-diketonate (n=1 for Cu (II) and Ni(II), n=2 for Cr(III)) and X=bridging anion was synthesized in order to study the effect of the bridging group on the magnetic exchange interaction parameter, J.

This thesis continues the study into the synthesis and analysis of metal poly - yndiyl complexes. These molecules have shown promise as model molecular wires. The study provides a general overview of the interest in carbon based molecules and introduces the need for molecular electronics. Some of the most promising classes of molecular wires are described before outlining the methods of evaluation. / Thesis (Ph.D.)--School of Chemistry and Physics, 2006.

Graduation date: 2003

The reactions and photochemistry of atomic and diatomic transition metals with methanol, water, hydrogen, and carbon monoxide in noble gas matrices at cryogenic temperatures have been studied with the use of Fourier Transform infrared inert matrix spectroscopy. Atoms and dimers of iron and cobalt reacted with methanol to form the adducts, M(CH30H) and M2(CH30H), respectively. M(CH30H) underwent metal insertion into the 0-H bond of methanol to yield methoxymetal hydride, CH3OMH, with irradiation of the matrix in the violet (400 nm < λ < 500 nm) region. Ultraviolet (280 nm < λ < 360 nm) photolysis of the matrix rearranged CH30MH to yield the methylmetal hydroxide species, CH3MOH. CH30MH dissociated into carbon monoxide and hydrogen after prolonged irradiation in the ultraviolet region. Surprisingly, nickel atoms reacted spontaneously to insert into the 0-H bonds of methanol and water to form CH30NiH and HONiH, respectively. Violet photolysis caused CH30NiH to rearrange to form methylnickel hydroxide, CH3NiOH. This is effectively a two step process of the C-0 activation of methanol by a nickel atom. In addition to rearrangement, CH30NiH dissociates into carbon monoxide and hydrogen with violet photolysis. Nickel dimers also reacted spontaneously with water to form both an adduct and insertion products. Atomic nickel spontaneously inserts into the H-H bond of molecular hydrogen to yield a bent nickel dihydride, NiH2, in krypton and xenon matrices. Nickel dimers and trimers insert into the H-H bond of hydrogen to form Nix(H)2. In addition to the insertion products, nickel atoms, dimers, and trimers form adducts molecularly with hydrogen to yield complexes of the form Nix(H2)y, where x or y = 1-3. Reactions of iron with carbon monoxide in an argon matrix yielded the iron-carbonyl complexes, Fex(CO)y, where x = 1-3 and y = 1-2.

Thesis (Ph. D.)--Ohio State University, 2009. / Title from first page of PDF file. Includes bibliographical references (p. 316-323).

Thesis (Ph. D.)--University of Hong Kong, 2002. / Includes bibliographical references (leaves 284-307).