“…In addition, certain mixed ligand Cu(II) complexes have entered clinical trials for various cancer types. 35,36 In the present study, prompted by our above success, we have isolated mixed ligand copper(II) complexes of the type [Cu (L)(diimine)](ClO 4 ) (1)(2)(3)(4)(5)(6), where the primary ligand HL is 2-formylpyridine-N 4 -phenylthiosemicarbazone and the co-ligand diimine is 2,2′-bipyridine (bpy, 1), 4,4′-dimethyl-2,2′-bipyridine (dmbpy, 2), 1,10-phenanthroline ( phen, 3), 5,6-dimethyl-1,10phenanathroline (5,6-dmp, 4), 3,4,7,8-tetramethyl-1,10-phenanthroline (3,4,7,8-tmp, 5) or dipyrido-[3,2-f:2′,3′-h]quinoxaline (dpq, 6) (Fig. 1), and illustrated their nanomolar cytotoxicity with the help of their DNA binding affinities and cleavage potentials.…”