Thesis (Ph.D.) -- McMaster University, 1999. / Includes bibliographical references (leaves 260-271). Also available via World Wide Web.

Thesis (Ph. D.)--University of Nevada, Reno, 2008. / "December, 2008." Includes bibliographical references. Online version available on the World Wide Web.

Thesis (Ph.D.)--University of Delaware, 2008. / Principal faculty advisor: Douglass F. Taber, Dept. of Chemistry & Biochemistry. Includes bibliographical references.

Thesis (Ph. D.)--University of California, Riverside, 2009. / Includes abstract. Available via ProQuest Digital Dissertations. Title from first page of PDF file (viewed March 10, 2010). Includes bibliographical references. Also issued in print.

Thesis (Ph. D.)--University of Pennsylvania, 1932. / "Reprinted from the Journal of the American chemical society, vol. 54, no. 9."

Thesis (Ph. D.)--University of Hong Kong, 2010. / Includes bibliographical references (leaves 303-328). Also available in print.

Thesis (Ph. D.)--University of Hong Kong, 2010. / Includes bibliographical references (leaves 303-328). Also available online.

M.Sc. / This study comprises the preparation and characterisation of new azolinylidene- and divinylcarbene complexes of chromium, molybdenum and tungsten, from 1- phenylpyrawle, 1-methylimidazole and 4,4-dimethyl-2,2-thienyloxazoline precursors. The reaction of 1-phenylpyrazolyllithium with (C0) 6M (M Cr, Mo or W) yields after alkylation with CH3S03CF3 in THE the two products (C0)5M[C(OCH3X(ONPhNCHC(H)] and (C0)5M[C(0{CH2}40C113)(aNPhNCH6H)]. A 'H NMR study indicates the existence of two isomers for each of the two tungsten CO'cli•lexes. 1-Methylimidazolyllithiura reacts with (CO)6M (M = Cr, Mo or W) to give the carbene complexes (C0)5MK'N(CH3)CHCH14(C I i 3)] after alkylation with CH3S03CF3, and the imine complexes (C0)5MOCHN(CH3)CH6H] after protonation with SO3CF3. Reaction of 1-methylimidazolyllithium with the anionic salt (C0)5 Cl = Cr or W), followed by alkylation with CH3S03CF3 affords both the mono- and bis(carbene) complexes, (CO)5M[CN(CH3)CHCHN(CH3)] and (C0)41v1[6N(CH3)CHCIRA(CH3)]2. The complex (C0)5W[C(0 {CH2 } 40C113)(t‘NPhNaldH)] reacts with phenylethynthiolate to furnish an anionic organometallic synthon that can either be alkylated or protonated. Protonation leads to two isomeric forms of the metal-coordinated thioaldehyde, (C0)5W4—SHC(Ph)=C(OCH3)(oNPhNCHell), whilst alkylation with various electrophilic reagents produces the metal coordinated dithio-esther (C0)5 W4--S=C [ SCH3] [C(Ph)=C(OCH3)(tNPhNaldH)]. The neutral divinylcarbene complexes (C0)5Cr{cC(a0CH2CMe2N)SC CH} (a) and (C0)5W{cC(COCH2CMe214)SCH9H} (19) are prepared by reaction of (C0)5MCr with the 3-lithiated thienyloxazoline, followed by alkylation with CH3S03CF3 . These complexes are the first examples of coordinated 'divinylcarbenes utilizing the group 6 transition metals, where the carbene carbon shows carbene character. They are also in another sense unique since the nucleopbutlic heteroatom where alkylation occurs, is situated outside the coordinated ring-system, and, therefore, more than two bonds removed fro the carbene carbon atom.

M.Sc. / Please refer to full text to view abstract.

Please read the abstract in the section 00front of this document / Dissertation (MSc (Chemistry))--University of Pretoria, 2006. / Chemistry / unrestricted