Cationic azomethine disperse dyes: Synthesis,antifungal activity and tinctorial properties of N-arylideneamino p-substituted pyridinium salts as possible dyes for synthetic fibres

In a four-step synthesis, a series of N-arylideneamino p-substituted pyridinium salt derivatives were prepared for use as cationic azomethine disperse dyes for polyester and polyacrylonitrile fibres. The effect of different substituents, in both of homo- and heterocyclic ring systems, on position of maximum absorbance in UV-vis spectra was used to explain the different hues of the prepared dyes. Besides, showing promising tinctorial properties, the synthesised dyes revealed fungicidal activity against Aspergillus niger. The structure of the hitherto prepared dyes was inferred by elemental and spectral data.