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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Synthesis, structural characterization and reactivity of metal-carboranyl and metal-dicarbollyl complexes. / CUHK electronic theses & dissertations collection

January 2011 (has links)
Liu, Dongmei. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 263-284). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.
2

Some organotransition metal chemistry of the carbon-carbon triple bond /

Koutsantonis, George Anthony. January 1989 (has links) (PDF)
Thesis (Ph. D.)--University of Adelaide, Dept. of Physical and Inorganic Chemistry, 1990. / Includes bibliographical references.
3

Structure-reactivity relationships in ring-slippage reactions

Fu, Yingmin January 2003 (has links)
There is no abstract available for this thesis. / Department of Chemistry
4

Some organotransition metal chemistry of the carbon-carbon triple bond / by George Anthony Koutsantonis

Koutsantonis, George Anthony January 1989 (has links)
Includes bibliographical references / 332, [6] leaves ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Physical and Inorganic Chemistry, 1990
5

Studies on the synthesis of main group and late transition element frameworks

Samanamu, Christian. January 2009 (has links) (PDF)
Thesis (Ph. D.)--Texas Christian University, 2009. / Title from dissertation title page (viewed June 2, 2009). Includes abstract. Includes bibliographical references.
6

Diphosphine Ligand Activation Studies with Organotransition-Metal Compounds

Wang, Jiancheng 12 1900 (has links)
Thermolysis of CoRu(CO)7(m -PPh2) (1) in refluxing 1,2-dichloroethane in the presence of the diphosphine ligands 2,3-bis(diphenylphosphino)maleic anhydride (bma) and 4,5-bis(diphenylphosphino)-4-cyclopenten-1,3-dione (bpcd) furnishes the new mixed-metal complexes CoRu(CO)4(μ -P-P)(μ -PPh2) [where P-P = bma (3); bpcd (6)], along with trace amounts of the known complex CoRu(CO)6(PPh3)(μ -PPh2) (4). The requisite pentacarbonyl intermediates CoRu(CO)5(μ -P-P)(μ -PPh2) [where P-P = bma (2); bpcd (5)] have been prepared by separate routes and studied for their conversion to CoRu(CO)4(μ -P-P)(μ -PPh2). The complexes 2/3 and 5/6 have been isolated and fully characterized in solution by IR and NMR spectroscopy. The kinetics for the conversion of 2→3 and of 5→6 were measured by IR spectroscopy in chlorobenzene solvent. On the basis of the first-order rate constants, CO inhibition, and the activation parameters, a mechanism involving dissociative CO loss as the rate-limiting step is proposed. The solid-state structure of CoRu(CO)4(μ -bma)(μ -PPh2) (3) reveals that the two PPh2 groups are bound to the ruthenium center while the maleic anhydride π bond is coordinated to the cobalt atom. Thermolysis of the cluster Ru3(CO)12 with the bis(phosphine)hydrazine ligand (MeO)2PN(Me)N(Me)P(OMe)2 (dmpdmh) in toluene at 75°C furnishes the known clusters Ru4(CO)12[μ -N(Me)N(Me)] (9) and Ru3(CO)11[P(OMe)3] (10), in addition to the new cluster Ru3(CO)10(dmpdmh) (8) and the phosphite-tethered cluster Ru3(CO)9[μ -P(OMe)3] (11). The simple substitution product Ru3(CO)10(dmpdmh), a logical intermediate to clusters 9-11, was synthesized by treating Ru3(CO)12 and dmpdmh with Me3NO in CH2Cl2 at room temperature, and independent thermolysis reactions using cluster 8 were shown to yield clusters 9-11. The tetrahedrane cluster FeCo2(CO)9(μ3-S) reacts with the redox-active ligand 4,5-bis(diphenylphosphino)-4-cyclopenten-1,3-dione (bpcd) to give the disubstituted cluster FeCo2(CO)7(bpcd)(μ3-S) as the sole product. This diphosphine-substituted cluster contains a cobalt-bound, chelating bpcd ligand. The solid-state structure has been unequivocally established by X-ray diffraction analysis. Cyclic voltammetric studies on FeCo2(CO)7(bpcd)(μ3-S) reveal the presence of two quasireversible redox responses assigned to the 0/1- and 1-/2- redox couples. The orbital composition of these redox couples has been examined by carrying out extended Hückel MO calculations on the model complex FeCo2(CO)7(H4-bpcd)(μ3-S), with the results being compared to related cluster compounds.
7

Transition metal promoted oxidation and reduction reactions

Gibson, Susan E. January 1984 (has links)
Two areas of organotransition metal chemistry and their potential application to organic transformations are discussed. The synthesis of cations of the type [Fe(η<sup>5</sup>-C<sub>5</sub>H<sub>5</sub>)(L)<sub>2</sub>(CO)]<sup>+</sup>, [Fe(η<sup>5</sup>-C<sub>5</sub>H<sub>4</sub>CH<sub>3</sub>)(L)<sub>2</sub>(CO)]<sup>+</sup>, [Fe(η<sup>5</sup>-C<sub>5</sub>(CH<sub>3</sub>)<sub>5</sub>)(L)<sub>2</sub>(CO)]<sup>+</sup> (where (L)<sub>2</sub>=(CO)<sub>2</sub>, (PPh<sub>3</sub>)(CO), (PMe<sub>3</sub>)(CO), (PPh<sub>3</sub>)<sub>2</sub>,(diphos) and (PMe<sub>3</sub>)<sub>2</sub>) and [Mo(η<sup>5</sup>-C<sub>5</sub>H<sub>5</sub>)(L)<sub>3</sub>(CO)] (where (L)<sub>3</sub>=(PPh<sub>3</sub>)(CO)<sub>2</sub>, (diphos)(CO) and (triphos)), many of them novel, is described. Investigations into the site of nucleophilic attack on the cations using hydride as a probe and the effect of varying the overall charge distribution of the cation are discussed. Hydride attack on a carbonyl ligand leads to the formation of metal formyl moieties and their detection by low temperature <sup>1</sup>H n.m.r. spectroscopy is described; furthermore, the fate of the metal formyls was found to be dependent upon the nature of the other ligands in the complex. A new criterion for establishing the stereoselectivity of nucleophilic attack on η<sup>5</sup>-C<sub>5</sub>H<sub>5</sub> ligands is proposed. Hydride attack on an η<sup>5</sup>-C<sub>5</sub>H<sub>4</sub>CH<sub>3</sub> ligand was discovered to be regioselective occurring at the carbon atom alpha to the methyl-bearing carbon. The direct oxidation of alkenes to epoxides by hydrogen peroxide was shown to be catalysed by some of the metal carbonyl cations. The use of organotitanium reagents to convert vic-dibromides and epoxides to alkenes is discussed. (C<sub>5</sub>H<sub>5</sub>)<sub>2</sub>TiCl<sub>2</sub> was shown to catalyse both a sodium amalgam debromination of disubstituted vic-dibromides and a zinc debromination of mono and disubstituted vic-dibromides. The latter reaction was developed into a synthetically useful procedure. Reduction of (C<sub>5</sub>H<sub>5</sub>)<sub>2</sub>TiCl<sub>2</sub> by both sodium amalgam and zinc dust gave reagents which deoxygenated epoxides. Investigations into the regioselectivity and chemoselectivity of these reagents are discussed. During the synthesis of molecules containing both vic-dibromide and epoxide functionalities, a novel cyclisation was discovered which may have relevance to the biosynthesis of certain marine natural products.
8

Sigmatropic and haptotropic shifts in complexes of cyclopenta[l]phenanthrene /

Rigby, Suzie S. January 1997 (has links)
Thesis (Ph.D.) -- McMaster University, 1997. / Includes bibliographical references. Also available via World Wide Web.
9

Haptotropic rearrangements in metal complexes of 4H-cyclopenta(def)phenanthrene.

Decken, Andreas. McGlinchey, M.J. Unknown Date (has links)
Thesis (Ph.D.)--McMaster University (Canada), 1994. / Source: Dissertation Abstracts International, Volume: 56-01, Section: B, page: 0240. Supervisor: M. J. McGlinchey.
10

Development of Nucleophile Assisting Leaving Groups (NALGs) and new stereoselective reactions using titanium(IV) reagents

Unknown Date (has links)
We report here the development of very efficient sulfonate based leaving groups, termed Nucleophile Assisting Leaving Groups (NALGs), to accelerate the rate of nucleophilic substitution reactions involving poor nucleophiles and/or substrates traditionally considered too hindered to undergo nucleophilic attack. Indeed NALGs have shown exceptional ability in improving rate of nucleophilic substitution reactions. New very mild stereoretentive halogenations and azidation reactions have also been developed for secondary cyclic alcohols using NALGs involving titanium(IV) reagents. This reaction is particularly significant since the carbon-halogen bond is found widely in natural products and is used extensively as a synthesis intermediate. Azide is also a synthetically important functional group from which a variety of biologically important functional groups are conveniently obtained. Though stereoretentive chlorination and bromination reactions are known, we have developed, for the first time, a stereoretentive azidation reaction using titanium(IV) azide, a reagent not previously used in organic synthesis. During our development of stereoretentive reactions, we eventually developed very efficient, mild, two-step one-pot stereoretentive halogenations (chlorination and bromination) using titanium(IV) halides as catalysts or stoichiometric reagents. These reactions were found to be particularly efficient for cyclic alcohols. An efficient one pot stereoretentive amidation reaction for secondary cyclic alcohols is also reported. The important features of this reaction are that, for the first time, chlorosulfite (prepared in situ from alcohol using thionylchloride) has been used as a leaving group and titanium(IV) fluoride as an activator. / Utilization of those two reagents is unique as thionylchloride has never been used for nucleophilic substitution reactions except in chlorination procedures. In addition, this work has found new and creative applications for titanium (IV) fluoride, a reactant rarely used in organic synthesis. Further exploiting the unique reactivity of titanium(IV), reactions of alkenes with various nucleophiles have been developed with this reagent in both catalytic and stoichiometric quantities. It was observed that a-substituted aromatic conjugated alkenes dimerize to generate important indan class of compounds which are very important in the polymer industry. In addition, non conjugated unactivated alkenes react with various nucleophiles to yield the adduct. / by Deboprosad Mondal. / Thesis (Ph.D.)--Florida Atlantic University, 2010. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2010. Mode of access: World Wide Web.

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