Azo-azomethine dyes with N, O, S donor set of atoms and their Ni(II) complexes: Synthesis, characterization and spectral properties

•New azo-azomethine dyes and their Ni(II) complexes have been synthesized.•The crystal structure of one metalized azo-azomethine dye has been reported.•The photophysical and thermal properties of the new dyes have been investigated.

New azo-azomethine dyes, L1–L3, with N2S2O2 donor set of atoms have been synthesized via condensation reaction of 1,2-bis(2-aminophenylthio)ethane with 5-(4-X-phenyl)-azo-salicylaldehyde (X = Cl, OMe and Me). The new dyes were characterized by IR, UV–Vis, 1H NMR and fluorescence spectroscopy as well as mass spectrometry and elemental analysis. Mononuclear nickel(II) complexes of the dyes have been also prepared. The crystal structure of [NiL1]·0.5H2O was determined by single-crystal X-ray diffraction. The thermal analysis data indicate that all prepared dyes, L1–L3, are thermally stable up to 320 °C. The fluorescence behavior of the prepared complexes have been also investigated and compared to those of L1–L3.

Graphical abstractThree new symmetrical bis-iminated azo-azomethine dyes and their Ni(II) complexes have been synthesized and characterized spectroscopically. The crystal structure of one metalized azo-azomethine dye was also reported. Furthermore, fluorescence behavior and thermal properties of all prepared dyes have been investigated.Figure optionsDownload full-size imageDownload as PowerPoint slide