Syntheses, crystal structures and in vitro anticancer activities of oxovanadium(IV) complexes of amino acid Schiff base and 1,10-phenanthroline ligands

摘要

Four oxovanadium(IV) complexes, namely [VO(desa-met)(phen)]center dot MeOH center dot 2H(2)O (1) (desa-met = Schiff base derived from 4-(diethylamino)salicylaldehyde and dl-methionine, phen = 1,10-phenanthroline), [VO(o-van-met) (phen)]center dot MeOH center dot CH2Cl2 center dot 3H(2)O (2) (o-van-met = Schiff base derived from o-vanillin and dl-methionine), [VO(dtbs-napa)(phen)]center dot 2H(2)O (3) (dtbs-napa = Schiff base derived from 3,5-di-tert-butyl salicylaldehyde and 3-(1-naphthyl)-l-alanine) and [VO(hyna-napa)(phen)]center dot 1.5H(2)O (4) (hyna-napa = Schiff base derived from 2-hydroxy-1-naphthaldehyde and 3-(1-naphthyl)-l-alanine), were synthesized and characterized by IR, HRMS, UV-vis spectra, molar conductance and single-crystal X-ray diffraction (XRD). X-ray structural analysis showed that the V(IV) atoms in all four complexes are six-coordinated in a distorted octahedral environment. In the crystals of complexes 1 and 2, pi-pi stacking interactions together with hydrogen bonds connect the molecular units into 2D networks. Meanwhile, CH-pi stacking interactions are observed between the aromatic rings in the crystals of 1 and 4, while the pi-pi stacking interactions between aromatic rings in the crystals of 2 and 3 are arranged with a face-to-face mode. The in vitro anticancer activities of these complexes against A-549 and HeGp2 cells were tested by MTT assay.