Stephanie Mueller

Chemistry and Biochemistry

Faculty Advisor: Vlad Iluc

Winter 2020-21 Project: Zinc(II) Carbene Synthesis and Reactivity

The Iluc group has synthesized the (bis[2-(di-iso-propylphosphino)phenyl]methylene (PCP) ligand and used it to make Fe, Pd, and Pt carbene complexes. These molecules proved to be useful in activating different substrates. My goal is to synthesize a Zn(II) carbene with this PCP ligand. If this is successful, then I will determine the carbene’s structure and reactivity, focusing on carbene insertion into C-H bonds. Kulkarni, Naveen V., et al. found that Zn(II) can do this in alkanes. 

Zn(II) is a cheap and earth-abundant metal that also has unique chemical properties. Zn(II)’s reactivity comes from the fact that that Zn has completely filled 3d orbitals, which gives it only one attainable oxidation state. Zn2+ is a redox-stable ion that can function as a Lewis acid–type catalyst whereby it stabilizes negative charge and activates substrates (Butler 1998). Zn(II) complexes also have ligand-field stabilization energies of zero (Huheey et al. 1993) in all geometries, allowing Zn(II) complexes to access multiple coordination geometries within a catalytic cycle. This would be especially useful to catalyze chemical transformations accompanied by changes in the metal coordination geometry. 

It is apparent that a Zn(II) catalyst would be useful because the human body uses Zn(II) in all six classes of enzymes (Maret W 2013). Creating this novel molecule could allow biochemists to perform biological reactions in vitro, or it could allow organic chemists to synthesize important organic molecules with a more energy efficient catalyst.