Synthesis, Characterization, and Reactivity of Novel Bis(phosphinoamide) Zr/Co Heterobimetallic Complexes Bearing N-isopropyl Phosphinoamide Ligands

Synthesis, Characterization, and Reactivity of Novel Bis(phosphinoamide) Zr/Co Heterobimetallic Complexes Bearing N-isopropyl Phosphinoamide Ligands
Author: Nathaniel C. McCutcheon
Publisher:
Total Pages: 0
Release: 2022
Genre: Chemistry, Inorganic
ISBN:

In light of growing environmental and economic concerns, there is a motivated effort to mimic the two-electron reactivity of precious transition metal complexes using more abundant, affordable, and non-toxic first row transition metals. The main challenge in this effort is that more sustainable first row transition metals do not readily undergo two-electron redox processes, which comprise many industrially relevant catalytic mechanisms, instead preferring to participate in one-electron reactions. One of several ways the Thomas group has approached this challenge is by tethering a Lewis acidic early metal to an electron-rich late metal via a bifunctional phosphinoamide ligand framework, allowing access to highly reduced late metal centers that have been shown to more favorably undergo two-electron redox processes. This thesis explores how the electron-donating properties of the phosphinoamide ligand impact the structure and reactivity of a novel series of bis(phosphinoamide) Zr/Co complexes. This series employs a more electron-donating iPrNPiPr2- ligand, as opposed to the XylNPiPr2- ligand previously featured in the group’s bis(phosphinoamide) Zr/Co systems. The relative electron density at the cobalt center is qualified using multiple spectroscopic and computational methods, and structural comparisons are made between analogous Zr/Co complexes bearing different ligands. These data are used to determine how increasing the electron-donating ability of the bis(phosphinoamide) framework impacts the thermodynamics of bond activation and the overall structure-reactivity relationship of Zr/Co complexes.

Olefin Polymerization

Olefin Polymerization
Author: Walter Kaminsky
Publisher: Wiley-VCH
Total Pages: 0
Release: 2006-08-18
Genre: Technology & Engineering
ISBN: 9783527317424

With an enormous velocity, olefin polymerization has expanded to one of the most significant fields in polymers since the first industrial use about 50 years ago. In 2005, 100 million tons of polyolefins were produced - the biggest part was catalyzed by metallorganic compounds. The Hamburg Macromolecular Symposium 2005 with the title "Olefin Polymerization" involved topics such as new catalysts and cocatalysts, kinetics, mechanism and polymer reaction engineering, synthesis of special polymers, and characterization of polyolefins. The conference combined scientists from different disciplines to discuss latest research results of polymers and to offer each other the possibility of cooperation. This is reflected in this volume, which contains invited lectures and selected posters presented at the symposium.