Redox-behavior and reactivity of formazanate ligands : Boron and aluminum chemistry

Abstract

Most of the chemical reactions in industry are two-electron processes, and these two-electron redox-reactions are exclusively carried out by the precious metals such as platinum, palladium, iridium, etc. There is a continuous quest for the development of catalysts based on less toxic, more abundant, and hence cheaper transition metals such as iron, cobalt, nickel. These base metals can often only change their oxidation states by one electron. For this reason, these metals are unable to perform the above mentioned two-electron redox-reactions. In order to overcome this problem, redox-active ligands are studied for the development of catalysts based on base metals. Redox-active ligands are those ligands which are actively participating in the bond-breaking/making processes by donating/accepting redox equivalents from/into their backbones during the catalytic reactions performed by their metal complexes. In this thesis, we have extended this strategy to main group complexes. We have described the synthesis, reduction chemistry and ligand-based reactivity of boron and aluminium compounds with redox-active formazanate ligands. The bonding, structural and electronic properties of these newly synthesized compounds has been described. The results presented in this thesis provides more insights into the redox-behavior and reactivity of main group complexes with formazanate ligands. The gained knowledge from this thesis forms a broad basis for the further development of the (catalytic) reactivity of complexes with this type of redox-active ligands.