Synthesis of a novel three-coordinate copper(I) complex: a structural mimic of the reduced form of type 1 site in copper protein

A new calix[4]arene ligand 3 bearing two imidazole and two methylthioethyl groups on the lower rim has been synthesized. The complex with Cu(I) was prepared and characterized by X-ray diffraction analysis and XPS spectrum. Such complex could be as the structural model of the permanently reduced form of type 1 site in human ceruloplasmin and other copper proteins.