- 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.
Search results
Showing 11 to 12 of 12 (0.075 seconds)Spelling suggestions: "subject:"metallocene catalysts"" "subject:"metallocenes catalysts""
| 11 |
ANSA-bridged and binuclear metallocene compounds of zirconium and hafniumDiamond, Gary M. January 1994 (has links)
This thesis describes the synthesis and characterisation of new mononuclear and binuclear zirconium and hafnium compounds containing ansa-bridged ligands. Some olefin polymerization studies, employing the new compounds as catalysts, are also presented. <strong>Chapter 1</strong> begins with an introduction to Ziegler-Natta polymerization of olefins, concentrating on recently developed metallocene-based catalyst systems. The second part of the Chapter charts the development of group 4 ansa-metallocene derivatives, especially their use as stereospecific catalysts. Finally, a review of binuciear group 4 metallocene compounds containing bridging bis(cyclopentadienyl)-type ligands is presented. <strong>Chapter 2</strong> describes the synthesis and characterisation of some novel mononuclear metallocene compounds of zirconium and hafnium containing ansa-bridged ligands. The ansa-bridged mononuclear compounds [{Me<sub>2</sub>C(η<sup>5</sup>-C<sub>5</sub>H<sub>4</sub>)(η<sup>2</sup>-C<sub>9</sub>H<sub>6</sub>)}M(η<sup>5</sup>C<sub>5</sub>H<sub>5</sub>)Cl] (M = Zr, Hf), [{(CH<sub>2</sub>)<sub>5</sub>C(η<sup>5</sup>-C<sub>5</sub>H<sub>4</sub>)(η<sup>2</sup>-C<sub>9</sub>H<sub>6</sub>)}M(η<sup>5</sup>-C<sub>5</sub>H<sub>5</sub>)Cl] (M = Zr, Hf) and [{Me<sub>2</sub>(η<sup>5</sup>-C<sub>5</sub>H<sub>4</sub>)(η<sup>3</sup>-C<sub>13</sub>H<sub>8</sub>)}Zr(η<sup>5</sup>-C<sub>5</sub>H<sub>5</sub>)Cl] are described, along with the X-ray crystal structures of the zirconium compounds. The η<sup>2</sup>-indenyl and η<sup>3</sup>-fluorenyl coordination modes observed for these compounds are unprecedented. The synthesis and characterisation of the novel, mononuclear ansa-bridged compounds [{Me<sub>2</sub>C(η<sup>5</sup>-C<sub>5</sub>H<sub>4</sub>)<sub<2</sub>}M(η<sup>5</sup>-C<sub>5</sub>H<sub>5</sub>)Cl] (M = Zr, Hf) is also described, along with their X-ray crystal structures. The variable temperature solid state <sup>13</sup>C CP/MAS NMR spectra of [{Me<sub>2</sub>C(η<sup>5</sup>-C<sub>5</sub>H<sub>4</sub>)<sub<2</sub>}M(η<sup>5</sup>-C<sub>5</sub>H<sub>5</sub>)Cl] (M = Zr, Hf) show slow rotation of the C<sub>5</sub>H<sub>5</sub> ring on the NMR timescale. <strong>Chapter 3</strong> describes the synthesis and characterisation of some novel homo- and hetero-binuclear metallocene compounds of zirconium and hafnium in which the metals are bridged by an unsymmetrical ansa ligand. The novel, chiral homobinuclear compounds [(η<sup>5</sup>-C<sub>5</sub>H<sub>5</sub>)MCl<sub>2</sub>{(η<sup>5</sup>-C<sub>5</sub>H<sub>4</sub>)CMe<sub>2</sub>(η<sup>5</sup>-C<sub>9</sub>H<sub>6</sub>)}MCl<sub>2</sub>(η<sup>5</sup>-C<sub>5</sub>H<sub>5</sub>)] (M = Zr, Hf) are described. The ansa-bridged mononuclear compounds [{Me<sub>2</sub>C(η<sup>5</sup>-C<sub>5</sub>H<sub>4</sub>)(η<sup>2</sup>-C<sub>9</sub>H<sub>7</sub>)M(η<sup>5</sup>-C<sub>5</sub>H<sub>5</sub>)Cl] (M = Zr, Hf) are used as reagents for the selective synthesis of the heterobinuclear analogues [(η<sup>5</sup>-C<sub>5</sub>H<sub>5</sub>)MCl<sub>2</sub>{(η<sup>5</sup>-C<sub>5</sub>H<sub>4</sub>)CMe<sub>2</sub>(η<sup>5</sup>-C<sub>9</sub>H<sub>6</sub>)}M*Cl<sub>2</sub>(η<sup>5</sup>-C<sub>5</sub>H<sub>5</sub>)] (M = Zr, M* = Hf ; M = Hf, M* = Zr) and the unsymmetrical homobinuclear compound [(η<sup>5</sup>-C<sub>5</sub>H<sub>5</sub>)ZrCl<sub>2</sub>{(η<sup>5</sup>-C<sub>5</sub>H<sub>4</sub>)CMe<sub>2</sub>(��<sup>5</sup>-C<sub>9</sub>H<sub>6</sub>)}ZrCl<sub>2</sub>(η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)]. The methylated derivatives [(η<sup>5</sup>-C<sub>5</sub>H<sub>5</sub>)M(CH<sub>3</sub>)<sub>2</sub>{(η<sup>5</sup>-C<sub>5</sub>H<sub>4</sub>)CMe<sub>2</sub>(η<sup>5</sup>-C<sub>5</sub>H<sub>6</sub>)}M*(CH<sub>3</sub>)<sub>2</sub>(η<sup>5</sup>-C<sub>5</sub>H<sub>5</sub>)] (M = Zr, M* = Zr, Hf; M = Hf, M* = Zr, Hf) are also described. The structurally related mononuclear compounds [(η<sup>5</sup>-C<sub>5</sub>H<sub>5</sub>)MCl<sub>2</sub>{(η<sup>5</sup>-C<sub>5</sub>H<sub>4</sub>)CMe<sub>2</sub>(C<sub>9</sub>H<sub>7</sub>)}] (M = Zr, Hf) and [(η<sup>5</sup>-C<sub>5</sub>H<sub>5</sub>)Zr(CH<sub>3</sub>)<sub>2</sub>{(η<sup>5</sup>-C<sub>5</sub>H<sub>4</sub>)CMe<sub>2</sub>(C<sub>9</sub>H<sub>7</sub>)}] have also been prepared. <strong>Chapter 4</strong> presents some olefin polymerization studies using the new compounds described in Chapter 3 as catalysts, along with either methylaluminoxane or the recently developed co-catalysts [Ph<sub>3</sub>C]<sup>+</sup>[B(C<sub>6</sub>F<sub>5</sub>)<sub>4</sub>]<sup>-</sup> and B(C<sub>6</sub>F<sub>5</sub>)<sub>3</sub>. <strong>Chapter 5</strong> provides the experimental details for the reactions described in this thesis and the characterising data for all new compounds are given in <strong>Chapter 6</strong> Crystallographic data for the for the X-ray structure determinations in Chapter 2 are given in the <strong>Appendices</strong>.
|
| 12 |
Synthesis, structure, and characterization of rare earth(III) transition metal cyanides lanthanide(II) and metallocene amidotrihydroborates /Wilson, Duane C., January 2009 (has links)
Thesis (Ph. D.)--Ohio State University, 2009. / Title from first page of PDF file. Includes bibliographical references (p. 316-323).
|
Page generated in 0.079 seconds