Synthesis, crystal structure, spectroscopic characterization, theoretical studies and cytotoxicity assays of novel two acylhydrazones and its Cu(II) complexes.

This work deals with the synthesis and characterization of two novel N-acylhydrazones (H2L1 and H2L2) and its Cu(II) complexes [Cu(HL1)2] and [Cu(HL2)2]. The crystal structures of H2L1 and H2L2 were solved by X-ray diffraction and a detailed analysis of the intermolecular interactions that stabilize the crystal packing of both ligands has been performed by Hirshfeld analysis and their associated two-dimensional fingerprint plots. The strength and nature of the intermolecular contacts were evaluated by using different computational tools including the quantum theory of atoms in molecules (QTAIM) and noncovalent (NCI) isosurfaces. Two new Cu(II) complexes were synthesized and characterized by the conjunction of different techniques (FTIR, Elemental Analysis, HRMS, UV-vis spectroscopies and thermogravimetric analysis (TGA)). Cytotoxicity assays of both ligands and its copper(II) complexes against three human tumor cell lines: MG-63 (bone), HCT-116 (colon) and MDA-MB-231 (breast), and non-tumor cell line (L929 cells) revealed an enhancement of the effectiveness as compared with both the ligand and the free metal ion.