Qing Yang

Date of Award

1-21-1998

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Chemistry

First Advisor

Michael D. Jensen

Abstract

This dissertation is divided into four subjects. They are: (1) the improved synthesis of known group 4 metallocenes; (2) the synthesis of new group 4 metallocenes; (3) the synthesis of new geminal diindenes, potential ligands for highly reactive polyolefin catalysts, and the improved synthesis of a known ligand precursor; and (4) the application of group 4 metallocenes in C-H activation.Rac-EBIZrCl$\sb2$ is prepared in 66% isolated yield via a non-aqueous, non-acidic workup. Additionally, the preparation of ligand precursor 1,2-(3-indenyl)ethane is significantly improved by inverse addition of indenyl anion to 1,2-dibromoethane. (THI)$\rm\sb2TiCl\sb2,$(THI)$\rm\sb2ZrCl\sb2,$ and previously unreported (THI)$\rm\sb2HfCl\sb2$ are prepared in 69%, 67%, and 62% isolated yields, respectively, via a non-hydrogenation route.New group 4 metallocenes rac-BBTHIMCl$\sb2$ (M = Ti, Zr) are prepared in 36% and 41% overall yield starting from MCl$\sb4,$ respectively. The X-ray structure of rac-BBTHIZrCl$\sb2$ is non-centric, belonging to the $P{\it 2\/}\sb1{\it 2\/}\sb1{\it 2\/}\sb1$ space group.A "one-pot" reaction has been developed for the preparation of geminal diindenes which possess either III$\sp {\rm o}$ or IV$\sp {\rm o}$ hindered carbons. Also, 6,6-diphenylpentafulvene, an important ligand precursor for known catalysts, is prepared in 81% isolated yield.A novel conversion of EBTHIZr(BINOL) to EBTHIZrCl$\sb2,$ which is one of the key transformations in the resolution of rac-EBTHIZrCl$\sb2,$ is described.And lastly, carbon-hydrogen bond activation of ethers by Cp$\rm\sb2MCl\sb2/AlCl\sb3/Mg\ (M=Ti,\ Zr,\ Hf)$ is presented.

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