New diaminomaleonitrile-based azo-azomethine dyes; synthesis, characterization and spectral properties

New diaminomaleonitrile-based azo-azomethine dyes were synthesized via a condensation between 2,6-bis(N-(2-amino-1,2-dicyanoetheneimino))-4-methylphenol and 5-(4-substituted-phenyl)-azo-salicyladehyde. FT-IR and 1H NMR spectroscopy and mass spectrometry studies as well as elemental analysis data revealed the symmetrical bis-iminated structures of the dyes. The electrochemical behavior of the dyes has been investigated by cyclic voltammetry. The effect of various solvents with different polarities on the UV–Vis spectra of the dyes was also studied. The thermal analysis data indicated that the framework of the dyes was stable up to 285 °C.

Two new symmetrical bis-iminated diaminomaleonitrile-based azo-azomethine dyes were synthesized via condensation of 2,6-bis(N-(2-amino- 1,2-dicyanoetheneimino))-4-methylphenol with azo-coupled salycilaldehyde precursors. Solvatochromic behavior and substituent effect of the prepared dyes in various solvents were evaluated.Figure optionsDownload as PowerPoint slideHighlights
► Two new thermally stable symmetrical bis-iminated diaminomaleonitrile-derived azo-azomethines have been synthesized.
► Solvatochromism and substituent effects of the new dyes were evaluated.
► Electrochemical behavior of the dyes has been investigated.