| dc.description.abstract | The selective functionalization of C-H bonds under mild and environmental-friendly conditions is a critical step in many major synthetic organic pathways. In 2016, the Serrano-Plana research group introduced a powerful C-H oxidation catalyst, which contains an iron center ligated to a strong-field N-methylated tetradentate aminopyridine macrocyclic ligand. Also, the Garcia-Bosch research group has shown that copper complexes catalyze the oxidation of alkanes with H2O2 in remarkable yields (50-60%). Inspired by their work, this research project focuses on development of a novel catalyst complex that consists of a copper (II) metal center bound to a N-methylated tetra-aza macrocyclic ligand (Me3L2 = 3,6,9-trimethyl-3,6,9,15-tetraazabicyclo[9.3.1]penta-deca-1,11,13-trien-13-ol). It is hypothesized that the N-methylated complex will have stronger electron-donating effect toward the metal center compared to the complex with non-methylated ligand. Moreover, the nitrogen atoms in the methylated complex are protected from the stringent oxidative conditions involving reactive oxygen species. In comparison to the unmethylated L2 ligand, experimental findings show stronger electron-donating effects from the methyl groups that shift the 1H NMR spectroscopy of the Me3L2 ligand upfield. However, the solution of the Me3L2 ligand-copper complex, or [Cu(Me3L2)Cl](ClO4), in water exhibits identical ultraviolet-visible (UV-Vis) spectroscopic characteristic compared to that of [Cu(L2)Cl](ClO4). Upon electrochemical analysis in dimethylformamide (DMF) solution with tetrabutylammonium fluoride (TBAF) as an electrolyte, the half-way potential of [Cu(Me3L2)Cl](ClO4) was found to be -880 mV (vs. Fc+/Fc = 0.0 mV). The electrochemical property of [Cu(Me3L2)Cl](ClO4) complex suggests both promising catalytic and biological activities that will be further studied. | |
