In this work, we have reported four azo dyes having a heterocyclic framework derived from 2-amino-5-nitrothiazole by a traditional diazo-coupling method in an acidic medium using four different coupling components and characterized them by different spectroscopic techniques. The comparative approach of both the experimental and computational calculations are performed by using DFT/B3LYP at 6-311++G (d, p) basis set with respect to the vibrational and absorption spectra of all the azo dyes. Also, HOMO-LUMO energy and other energy-related global parameters are calculated. The absorption spectra were recorded in the region of 200–700 nm, and the results exhibited a unique absorption in the longer wavelength due to the presence of a nitro group in the moiety as well as solute–solvent interaction. From the quantum chemical calculation values, there is a good correlation that exists between the experimental and computational studies. Furthermore, the antibacterial and antioxidant properties of the azo dyes were evaluated by the disc diffusion method and DPPH assay respectively. The results revealed that all the compounds showed potent inhibitory effect towards the tested pathogenic strains and scavenging activity.

中文翻译：

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硝基噻唑掺入杂环偶氮染料的合成、表征、计算和生物学研究

在这项工作中，我们报告了四种具有杂环骨架的偶氮染料，它们通过传统的重氮偶联方法在酸性介质中使用四种不同的偶联组分衍生自 2-氨基-5-硝基噻唑，并通过不同的光谱技术对其进行表征。实验和计算计算的比较方法是通过使用 DFT/B3LYP 在 6-311++G (d, p) 基组中对所有偶氮染料的振动和吸收光谱进行的。此外，还计算了 HOMO-LUMO 能量和其他与能量相关的全局参数。吸收光谱记录在 200-700 nm 范围内，由于部分中存在硝基以及溶质 - 溶剂相互作用，结果在较长波长处表现出独特的吸收。从量子化学计算值，实验和计算研究之间存在良好的相关性。此外，偶氮染料的抗菌和抗氧化性能分别通过圆盘扩散法和 DPPH 测定进行评估。结果表明，所有化合物均显示出对受试病原菌株的有效抑制作用和清除活性。