Phenylazoindole dyes – Part I: The syntheses, characterizations, crystal structures, quantum chemical calculations and antimicrobial properties

• Published in: Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy Vol. 113; pp. 314 - 324
• Main Authors: Seferoğlu, Zeynel, Yalçın, Ergin, Babür, Banu, Seferoğlu, Nurgül, Hökelek, Tuncer, Yılmaz, Ebru, Şahin, Ertan
• Format: Journal Article
• Language: English
• Published: England Elsevier B.V 01-09-2013
• Subjects: Absorption; Anti-Bacterial Agents - chemical synthesis; Anti-Bacterial Agents - chemistry; Anti-Bacterial Agents - pharmacology; Anti-Infective Agents - chemical synthesis; Anti-Infective Agents - chemistry; Anti-Infective Agents - pharmacology; Antifungal Agents - chemical synthesis; Antifungal Agents - chemistry; Antifungal Agents - pharmacology; Antimicrobial activity; Azo–hydrazone tautomer; Bacteria - drug effects; Coloring Agents - chemical synthesis; Coloring Agents - chemistry; Coloring Agents - pharmacology; Crystal structure; Crystallography, X-Ray; DFT calculations; Dimethyl Sulfoxide - chemistry; Fungi - drug effects; Hydrogen Bonding; Indoles - chemical synthesis; Indoles - chemistry; Indoles - pharmacology; Microbial Sensitivity Tests; Models, Molecular; Molecular Conformation; Phenylazoindole dye; Quantum Theory; Solutions; Solvents; Stereoisomerism; Thermodynamics; Antimicrobial activity; Phenylazoindole dye; Azo–hydrazone tautomer; DFT calculations; Crystal structure
• ISSN: 1386-1425; 1873-3557
• DOI: 10.1016/j.saa.2013.04.081

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•Phenylazoindole based new organic dyes have been synthesized and characterized.•The most stable tautomeric form of the dyes have been determined easily with using model compounds in solution.•The quantum chemical calculations results showed that the azo tautomer is dominant tautomeric form.
In this study, the synthesis of four new phenylazo indole dyes (dye 1–4) were carried out by diazotization of 4-aminoacetophenone and coupling with various 2- and 1,2-disubstituted indole derivatives. The dyes were characterized by UV–vis, FT-IR, 1H NMR, HRMS and X-ray single crystal diffraction methods. Azo–hydrazone tautomeric bahavior of the dyes in different solvents (DMSO, methanol, acetic acid and chloroform) was investigated by using 1H NMR and UV–vis results. The experimental results were compared with the corresponding calculated values. The results of experimental data and theoretical calculations showed that the azo tautomer is more stable than hydrazone tautomer. In addition to this, the antimicrobial activity of the dyes was also evaluated.