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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.
11

'n Studie oor kraking en hidrokraking met wolfram houdende katalisatore

25 November 2014 (has links)
D.Sc. / Please refer to full text to view abstract
12

The preparation and characterization of cyclopendatienyl-triacarbnyl-tungsten complexes containing catenated polysulfur ligands /

Hartgerink, Judy. January 1981 (has links)
No description available.
13

Sintese en strukture van nuwe tioon-, seloon-, tiokarbeen en selenokarbeenkomplekse van wolframpentakarboniel

Marais, Charles Francois 01 December 2014 (has links)
D.Sc. / Please refer to full text to view abstract
14

The preparation and characterization of cyclopendatienyl-triacarbnyl-tungsten complexes containing catenated polysulfur ligands /

Hartgerink, Judy. January 1981 (has links)
No description available.
15

Desulfurdimerization of dithioacetals with tungsten hexacarbonyl.

January 1989 (has links)
Lam Lung Yeung. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1989. / Bibliography: leaves 73-76.
16

The chemistry of η-cycloheptatrienyl derivatives of molybdenum and tungsten

Ng, Kee-Pui Dennis January 1993 (has links)
This thesis describes the synthetic, structural and reactivity studies of η- cycloheptatrienyl-molybdenum and -tungsten chemistry. Chapter 1 presents an overview of the chemistry of η-cycloheptatrienyl derivatives of transition metals, in particular group 6 metals. The functional group properties of the η-cycloheptatrienyl ligand are also discussed. Chapter 2 describes the synthesis of [Mo(η-C<sub>7</sub>H<sub>7</sub>)(η<sup>5</sup>-C<sub>7</sub>H<sub>9</sub>)] from Mocl<sub>5</sub> or [MoCl<sub>4</sub>(thf)<sub>2</sub>], which provides a convenient route to η-cycloheptatrienyl-molybdenum compounds, such as [Mo(η-C<sub>7</sub>H<sub>7</sub>)LX<sub>2</sub>] and [Mo(η-C<sub>7</sub>H<sub>7</sub>)L<sub>2</sub>X], where L = tertiary phosphines or acetonitrile and X = halogen, [NBu<sub>4</sub>] [Mo(η-C<sub>7</sub>H<sub>7</sub>)I<sub>3</sub>], [Mo(η-C<sub>7</sub>H<sub>7</sub>)(η- C<sub>5</sub>H<sub>4</sub>R)] (R = H or Me) and [Mo(η-C<sub>7</sub>H<sub>7</sub>)(η<sup>5</sup>-C<sub>9</sub>H<sub>7</sub>)]. The X-ray crystal structures of [Mo(η-C<sub>7</sub>H<sub>7</sub>)(MeCN)I<sub>2</sub>], [NBu<sub>4</sub>][Mo(η-C<sub>7</sub>H<sub>7</sub>))I<sub>3</sub>] and [Mo(η-C<sub>7</sub>H<sub>7</sub>)(η-C<sub>5</sub>H<sub>4</sub>Me)] are presented. The compound [Mo(η-C<sub>7</sub>H<sub>7</sub>))(MeCN)I<sub>2</sub>], mixed with Me<sub>3</sub>SiCH<sub>2</sub>MgCl, is a catalyst for ring-opening polymerisation of norbornene giving trans polymer exclusively. The electron-transfer complexes [Mo(η-C<sub>7</sub>H<sub>7</sub>)(η-C<sub>5</sub>H<sub>4</sub>Me)][tcne] and {[Mo(η-C<sub>7</sub>H<sub>7</sub>))(η- C<sub>5</sub>H<sub>5</sub>}<sub>2</sub>[tcnq]} and the intercalation compound {ZrS<sub>2</sub>[Mo(η-C<sub>7</sub>H<sub>7</sub>)(η-C<sub>5</sub>H<sub>4</sub>Me)]o.22} are also described. An extension of these synthetic pathways to tungsten is described in chapter 3. Reduction of WCl<sub>6</sub> with sodium amalgam in the presence of cycloheptatriene gives [W(η- C<sub>7</sub>H<sub>7</sub>)(η<sup>5</sup>-C<sub>7</sub>H<sub>9</sub>)], which is a precursor to the compounds [W(η-C<sub>7</sub>H<sub>7</sub>)(MeCN)I<sub>2</sub>], [W(η- C<sub>7</sub>H<sub>7</sub>)(PMe<sub>3</sub>)X<sub>2</sub>] (X = Br or I), [W(η-C<sub>7</sub>H<sub>7</sub>)(dmpe)I], [W(η-C<sub>7</sub>H<sub>7</sub>)(η-C<sub>5</sub>H<sub>4</sub>R)] (R = H or Me) and [Mo(η-C<sub>7</sub>H<sub>7</sub>)(η<sup>5</sup>-C<sub>9</sub>H<sub>7</sub>)]. The [W(η-C<sub>7</sub>H<sub>7</sub>)(MeCN)I<sub>2</sub>] / Me<sub>3</sub>SiCH<sub>2</sub>MgCI system is an active catalyst for ring opening polymerisation of norbomene. The electronic structures of [W(η-C<sub>7</sub>H<sub>7</sub>)(η-C<sub>5</sub>H<sub>4</sub>R)] (R= H or Me) are discussed on the basis of their He I and He II photoelectron spectra. The intercalation of [W(η-C<sub>7</sub>H<sub>7</sub>)(η-C<sub>5</sub>H<sub>4</sub>Me)] into ZrS<suv>2</sub> is also described. The magnetic properties of the 17-electron compounds [Mo(η-C<sub>7</sub>H<sub>7</sub>)(MeCN)I<sub>2</sub>], [Mo(η-C<sub>7</sub>H<sub>7</sub>)(PMe<sub>3</sub>)I<sub>2</sub>], [W(η-C<sub>7</sub>H<sub>7</sub>)(MeCN)I<sub>2</sub>], [W(η-C<sub>7</sub>H<sub>7</sub>)(PMe<sub>3</sub>)I<sub>2</sub>] and [W(η-C<sub>7</sub>H<sub>7</sub>) (PMe<sub>3</sub>)I<sub>2</sub>] are discussed in chapter 4. They behave as one-dimensional antiferromagnets which was suggested by magnetic model fittings and the crystal structure of [Mo(η-C<sub>7</sub>H<sub>7</sub>)(MeCN)I<sub>2</sub>]. Chapter 5 comprises of two parts. The first part describes a new series of binuclear thiolato-bridged molybdenum complexes [(η-C<sub>7</sub>H<sub>3</sub>R¹<sub>4</sub>)Mo(μ-SR²)<sub>3</sub> Mo- (η-C<sub>7</sub>H<sub>3</sub>R¹<sub>4</sub>)][BF<sub>4</sub>] (R¹ = H or Me; R² = Et, Pr, Bu, Ph or CH<sub>2</sub>Ph). Dynamic NMR studies reveal that all of these complexes (except for R² = Ph) are fluxional due to inversion at the pyramidal sulfur centre. Cyclic voltammetric studies show that they undergo two reversible one-electron reductions. Second part of this chapter describes the new bridging-imido compound [(η-C<sub>7</sub>H<sub>7</sub>)Mo(μ-NAr)<sub>2</sub>Mo(η-C<sub>7</sub>H<sub>7</sub>)] (Ar = 2,6- diisopropylphenyl). Chapter 6 discusses the η-l,2,4,6-tetramethylcycloheptatrienyl-molybdenum system. The new η-tetramethylcycloheptatriene molybdenum compounds [M'(η-C<sub>7</sub>H<sub>4</sub>Me<sub>4</sub>- 1,3,5,7)],[M'(η-C<sub>7</sub>H<sub>4</sub>Me<sub>4</sub>-l,2,4,6)] and [M'(η-C<sub>7</sub>H<sub>4</sub>Me<sub>4</sub>-l,3,4,6)], M' = Mo(CO)<sub>3</sub>, and new η-tetramethylcycloheptatrienyl-molybdenum compounds [M"(CO)<sub>3</sub>]+, [M"(CO)<sub>2</sub>C1], [M"(dmpe)Cl], [M"(η-C<sub>6</sub>H<sub>5</sub>Me)]+ and [M"(acac)(PPh<sub>3</sub>)], M" = Mo(η- CC<sub>7</sub>H<sub>3</sub>Me<sub>4</sub>-1,2,4,6), and [Mo(η<sup>3</sup>-C<sub>7</sub>H<sub>3</sub>Me<sub>4</sub>-l,2,4,6)(dmpe)(CO)<sub>2</sub>Cl] are described. Chapter 7 gives the experimental details for the work described in preceeding chapters. Appendix A presents characterising data for all the new compounds and previously unreported data for known compounds. Crystallographic details for the X-ray structure determinations and X-ray powder diffraction data are listed in Appendix B and C respectively.
17

Synthesis and optical properties of four oligothiophene-ruthenium complexes and synthesis of a bidentate ligand for C-F bond activation /

Bair, Joseph Spencer, January 2006 (has links) (PDF)
Thesis (M.S.)--Brigham Young University. Dept. of Chemistry and Biochemistry, 2006. / Includes bibliographical references.
18

Oxidation and reduction of small molecules by tungsten and osmium compounds /

Crevier, Thomas J. January 1998 (has links)
Thesis (Ph. D.)--University of Washington, 1998. / Vita. Includes bibliographical references (leaves [225]-233).
19

The preparation of seleno compounds of tungsten and molybdenum

Fruehan, August George. January 1928 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1928. / Typescript. Includes bibliographical references.
20

Synthesis and photocatalytic activity of the MoS₂ and WS₂ nanoparticles in degradation of organic compounds

James, Derak J. January 2009 (has links)
Thesis (M.S.)--Ball State University, 2009. / Title from PDF t.p. (viewed on June 07, 2010). Includes bibliographical references (p. [65]).

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