Spectroscopic and Computational Investigations of Azo‐Hydrazone Tautomeric Forms of Diethylamino Phenol‐Based Mono‐azo Molecules and Their In Vitro Biological Evaluations

• Published in: ChemistrySelect (Weinheim) Vol. 9; no. 38
• Main Authors: Zahara, Fiza Noor, Keshavayya, J., Krishnamurthy, Chethan, Pasha, K. M. Mussuvir, Shekharagouda, Pampapathi
• Format: Journal Article
• Language: English
• Published: 01-10-2024
• Subjects: Antibacterial; Antioxidant studies; Azo dyes; Computational; UV absorption and Photoluminescence
• ISSN: 2365-6549; 2365-6549
• DOI: 10.1002/slct.202402963

The present work illustrates the synthesis of some new mono‐azo dyes, which include different amines such as 2‐amino thiazole, 2‐amino‐5‐methyl‐1,3,4‐thiadiazole, and 2‐amino‐5‐methyl thiazole with 3‐diethylamino phenol as a common coupling component. The prepared azo moieties were structurally confirmed by spectroscopic techniques like NMR (1H and 13C), FT‐IR, UV –absorption, and emission properties, and HR‐MS spectrometry. Significant variations in the absorption and emission wavelengths of the azo dyes were shown by the solvatochromic behavior, which also provided an important insight into the formation of azo and hydrazone tautomeric forms. The density functional theory of the dyes was carried out to know the HOMO‐LUMO energy gaps, molecular electrostatic potential, and reduced density gradient. Further, they were screened for their in vitro antibacterial and antioxidant activities, and the results showed that the compounds exhibited excellent potentialities against various strains.
The synthesized mono‐azo dyes (N1‐N3) are characterized by various spectral features and hence show good confirmity with the proposed structures. The tautomeric phenomena of these compounds are confirmed by UV absorption studies. The DFT simulations are performed to compute a variety of properties. Also, in vitro biological assessment including antibacterial and antioxidant studies, shows that the compounds are potentially active.