Synthesis, crystal structure and biological properties of a fluorophore-labelled mixed-ligand copper(II) complex incorporating N-hydroxynaphthalene-1,8-dicarboximide.

The mixed-ligand fluorophore-labelled copper(II) complex aqua[2,4-dioxo-3-azatricyclo[7.3.1.0 5,13 ]trideca-1(12),5,7,9(13),10-pentaen-3-olato-κ 2 O 2 ,O 3 ](1,10-phenanthroline-κ 2 N,N')copper(II) nitrate, [Cu(C 12 H 6 NO 3 )(C 12 H 8 N 2 )(H 2 O)]NO 3 ·CH 3 OH or [Cu(L)(phen)(H 2 O)]NO 3 ·CH 3 OH (where phen is 1,10-phenanthroline and HL is N-hydroxynaphthalene-1,8-dicarboximide), (1), was synthesized and structurally characterized. The structure of (1) was confirmed by single-crystal X-ray structure determination. The complex crystallized in the triclinic space group P-1. The geometry around the copper centre is distorted square pyramidal, with the apical position occupied by a water molecule. The complex is highly fluorescent in organic and aqueous solutions. It has good anticancer activity, with an IC 50 value of 17 µM, which is almost five times greater than cisplatin (IC 50  = 82 µM) under identical experimental conditions.