Zhou, L: Bis(imidazole)thioether, Tris(imidazole) Ligands An

The focus of this research project is to synthesize novel bis(imidazole)thioether and tris(imidazole) tripodal ligands and develop new model complexes that more accurately mimic structural and reactivity features of the active sites of copper hydroxylase enzymes. New sterically hindered tris(imidazole) tripodal ligands were prepared to mimic the coordination environment of CuA active site. Copper(I) derivatives of the tris(imidazole) ligands exhibit modest dioxygen reactivity. Novel 2-tethered sterically hindered bis(imidazole) thioether tripodal ligands were prepared to provide the same (imidazole)2(thioether) ligand set as the CuB binding site of the copper hydroxylase enzymes. These complexes exhibit several close parallels with the CuB site of the enzymes. More biomimetically accurate 4-tethered bis (imidazole)thioether ligands and their copper complexes that incorporate the ligand set of the CuB site of the copper hydroxylase enzymes have been prepared and characterized. The imidazole-based substituent variations on the BIT ligands can have important effects on the oxygenation and electrochemical oxidation of corresponding copper(I) complexes.