Novel monoazo disperse and cationic dyes: preparation, structure investigation, study of spectroscopic, antibacterial and antifungal potential

A series of azo naphthalimide dyes were prepared by coupling N,N-diethyl-m-toluidine with three heterocyclic amines as the diazo components. The structures of the nine prepared azo dyes were fully characterized by Fourier transform infrared, differential scanning calorimeter, thin-layer chromatography, proton and carbon nuclear magnetic resonance, mass spectrometry, elemental analysis (CHNS), and UV-Vis spectroscopic techniques. UV-Vis studies represented that all dyes have molar extinction coefficients between 30,000 and 61,000 M-1 cm(-1) and have maximum wavelengths between 545 and 558 nm in DMF solution. The newly synthesized dyes were screened for their potential antimicrobial activities against Gram-positive, Gram-negative bacteria and fungi using the cup plate and broth microdilution methods. The results of antibacterial and antifungal activities exhibited significant inhibitory effect against the test microorganisms in vitro. [GRAPHICS] .