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.

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

published_or_final_version / Chemistry / Doctoral / Doctor of Philosophy

published_or_final_version / Chemistry / Doctoral / Doctor of Philosophy

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