Square‐Planar Copper(II) complexes from a Zwitterionic Schiff‐Base N2/N2/2‐Donor Ligand: DNA Interaction and Cytotoxicity

Abstract

AbstractA new tetradentate ligand, namely 3,3′‐((1E,1′E)‐(ethane‐1,2‐diylbis(azaneylylidene))bis(methaneylylidene))bis(pyridin‐2‐amine) (en2ampy) was prepared and two copper(II) complexes, viz. [Cu(en2ampy)]Cl2 (1) and [Cu(en2ampy)](NO3)2 (2), were obtained through its reaction with copper(II) chloride and copper(II) nitrate, respectively. The single‐crystal X‐ray structure of the compounds showed that the metal centre was coordinated in a square‐planar fashion by a doubly deprotonated en2ampy acting as a tetradentate / ‐donor ligand. DNA‐binding studies revealed that 1 and 2 were electrostatically binding to DNA, probably in the grooves and cytotoxicity assays showed that the complexes were clearly more efficient than cisplatin against ovarian carcinoma (A2780) cells and the cisplatin‐resistant (A2780Cis) ones.