The synthesis, optical properties, theoretical calculations, and antibacterial activities of a series of new red heterocyclic dyes derived from imidazo[1,2-a]pyridine are presented. 3-(Hydroxyimino)imidazo[1,2-a]pyridin-2(3H)-ylidene)-1-arylethanones are obtained from the reaction of 3-nitroimidazo[1,2-a]pyridine with substituted acetophenone derivatives in good yields (65%–72%). The structures are confirmed by spectral and analytical data, and the optical properties of the dyes are characterized by spectrophotometry. Density functional theory calculations are performed to provide the optimized geometries and relevant frontier orbitals. Calculated electronic absorption spectra are also obtained by the time-dependent density functional theory method. Moreover, the antibacterial activities (minimum inhibitory concentration) of the new dyes against Gram-positive and Gram-negative bacterial species are determined (minimum inhibitory concentration: 5–200 μg mL−1).

中文翻译：

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3-(Hydroxyimino)imidazo[1,2-a]pyridin-2(3H)-ylidene)-1-arylethanones 作为新的红色杂环染料：合成、光谱研究、量子化学研究和抗菌活性

介绍了一系列衍生自咪唑并[1,2-a]吡啶的新型红色杂环染料的合成、光学性质、理论计算和抗菌活性。3-(Hydroxyimino)imidazo[1,2-a]pyridin-2(3H)-ylidene)-1-arylethanones 由 3-nitroimidazo[1,2-a]pyridine 与取代的苯乙酮衍生物以良好的收率反应获得(65%–72%)。结构由光谱和分析数据证实，染料的光学性质由分光光度法表征。执行密度泛函理论计算以提供优化的几何形状和相关的前沿轨道。计算的电子吸收光谱也可以通过时间相关的密度泛函理论方法获得。而且，