C-X bond activation by low-valent first-row transition metal centers.

Abstract

Low-valent metal centers have been of great interest for bond activation considering these species are highly reducing. In this work, two different ligand systems were used to create low-valent metal centers. In both cases, a family of metal complexes was made with each ligand to understand its binding properties and geometries. The first part of this thesis will focus on developing structural models for cobalamin, a cobalt metal center supported by the corrin, a monoanionic tetradentate nitrogen donor ligand. Our interest in modeling cobalamin stems from its ability to remediate chlorinated contaminants from groundwater. Specifically, the cobalt(I) oxidation state of cobalamin is responsible for its reactivity towards C-X bonds. Through the use of beta-diketiminate ligand with pendant donor arms, a successful structural model for cobalamin was created and its reduced cobalt(I) complex was reactive towards C-X bonds. The second part of this work will examine first-row transition metal complexes synthesized with the wide bite-angle disphophine, 4,6-bis(3-diisopropylphosphinophenyl)dibenzofuran. A reduced nickel(I) complex made with this ligand was characterized and its reactivity towards C-X bonds and metathesis was explored.