To mimic superoxide dismutase, two new copper(II) complexes, [Cu(bqad)X 2 ] (1, X=Cl; 2, X=Br; where bqad=N,N′-bis(2-quinolinylmethyl)amantadine), have been synthesized and characterized by elemental analysis, electronic absorption, IR and single crystal X-ray diffraction. The copper ions in 1 and 2 have a penta-coordination geometry, composed of three nitrogen atoms from one bqad ligand and two halide anions. The complexes showed quasi-reversible one-electron Cu(II)/Cu(I) redox waves, as determined by cyclic voltammetry. By using an NBT assay at pH 7.8, the superoxide dismutase (SOD)-like activity (IC 50 ) of 1 and 2 were measured to be 0.43 and 0.32μM, respectively. The enhancement in the SOD-like activity of 2 can be ascribed to the formation of the species [Cu(bqad) 2 (H 2 O) 2 ] 2+ in aqueous solution due to the two labile bromine ions. Furthermore, DFT calculations were performed in order to understand the relationship between the structures and activities of the mimics.