Immobilized complexes of copper(II) chloride with triethylenetetramine as catalysts for the reaction of C-Cl bond metathesis

The structure and activity of C–Cl bond metathesis catalysts containing CuCl2and triethylenetetramine (TETA) supported on silica were studied. The catalysts were found to contain ∼40% Cu(II) as paramagnetic complexes of the composition Cu(TETA)2Cl2and diamagnetic binuclear or polynuclear copper complexes, which are undetectable by EPR spectroscopy. The catalytic activity of the test systems in the radical reaction of C–Cl bond metathesis in the CCl4–C10H22system was maximum at a Cu(II) concentration of ∼0.5 wt % on the support. A kinetic scheme was proposed, which suggests that only mononuclear copper complexes participate at the stage of radical generation, whereas termination can also occur on binuclear or polynuclear complexes.