Monodentate Schiff base ligands: Their structural characterization, photoluminescence, anticancer, electrochemical and sensor properties

•Two novel Schiff base ligands were prepared and structurally characterized.•Absorption, photoluminescence and electrochemical properties of the Schiff bases were examined.•Sensor properties of the compounds were examined.•Anticancer activity of the compounds were investigated.

Two Schiff base compounds, N,N′-bis(2-methoxy phenylidene)-1,5-diamino naphthalene (L1) and N,N′-bis(3,4,5-trimethoxy phenylidene)-1,5-diamino naphthalene (L2) were synthesized and characterized by the analytical and spectroscopic methods. The electrochemical and photoluminescence properties of the Schiff bases were investigated in the different conditions. The compounds L1 and L2 show the reversible redox processes at some potentials. The sensor properties of the Schiff bases were examined and color changes were observed upon addition of the metal cations, such as Hg(II), Cu(II), Co(II) and Al(III). The Schiff base compounds show the bathochromic shift from 545 to 585 nm. The single crystals of the compounds (L1) and (L2) were obtained from the methanol solution and characterized structurally by the X-ray crystallography technique. The molecule L2 is centrosymmetric whereas the L1 has no crystallographically imposed molecular symmetry. However, the molecular structures for these compounds are quite similar, differing principally in the conformation about methoxy groups and the dihedral angle between the two aromatic rings and diamine naphthalene.

Graphical abstractThe ligands were structurally characterized by single crystal X-ray diffraction study. The molecule L2 is centrosymmetric whereas the L1 has no crystallographically imposed molecular symmetry. The antiproliferative activities of compounds L1 and L2 aganist C6 cell line (a). ∗P < 0.01 when compared to control groups (one-way ANOVA following the Duncan’s multiple comparison test).Figure optionsDownload full-size imageDownload as PowerPoint slide