Synthesis of Metal-Metal Bond Containing Complexes with Multiple Open Coordination Sites and Multi-electron Redox Capabilities

Abstract

This dissertation focuses on the synthesis and characterization of compounds containing metal-metal bonds between first row transition metals. More specifically, this research focused on creating metal-metal bond containing complexes with multiple open coordination sites or redox active metal pairs capable of mediating multi-electron redox processes. This thesis covers three related studies. In the first study, heterobimetallic complexes that pair cobalt and copper were synthesized and characterized by a suite of physical methods. A covalent cobalt-copper bond is present in the oxidized [CoCu]4+ state, and the bond is broken upon reduction to [CoCu]3+ state. The reduced state has up to three open coordination sites. Cyclic voltammetry shows that the cobalt-copper unit is capable of two-electron redox changes. In the second study, a complex containing a chromium-chromium triple bond is investigated. The [CrCr]4+ unit is capable of two closely separated oxidations as studied by cyclic voltammetry, UV-Vis, and EPR spectroscopy. In the third study, new ligand designs for coordinatively unsaturated bimetallic compounds are described. Investigations into the metalation of these multifunctional ligands are detailed. A set of isolated monometallic complexes were characterized and they were investigated for the ability to bind a second metal.