Synthesis, structure investigation, spectral characteristics and biological activities of some novel azodyes

Four novel azo compounds were synthesized; o-phenylazo- (C14H13N3O2) (I), p-bromo-o-phenylazo- (C14H13BrN3O2) (II), p-methoxy-o-phenaylazo- (C15H16N3O3) (III) and p-nitro-o-phenylazo-p-acetamidophenol (C14H13N4O4) (IV). These compounds were carefully investigated using elemental analyses, UV–vis, FT-IR, 1H NMR and mass spectra. Also, the effects of p-substituents such as bromo, methoxy and nitro groups on the mass fragmentation pathways of these dyes were studied using Hammet's effects. This research aimed chiefly to threw lights on the structures–stability relationship of four novel newly prepared azo derivatives of p-acetoamidophenol. The data obtained referred to the variation of mass fragmentation pathways with the variation of p-substituent of these dyes which can be used in industry for various dyeing purposes. This variation is also correlated and verified by molecular orbital calculations which were done on ionic forms of these dyes using semi empirical PM3 program. The biological activities of these dyes were also investigated and its structure relationship was correlated.