Abstract. Synthesis of substituted pyrazines from readily available methyl aryl/heteroaryl ketones and 1,2-diamines were achieved using highly stable and reusable ferrite stabilized copper nanoparticles (Fe3O4-CuO) as catalyst. The reaction proceeds via cascade imine formation-oxidative cyclization method under oxygen atmosphere. The nanocatalysts were easily recovered and reused upto three consecutive cycles without any significant decrease in particle size, catalytic activity and reaction yield as evidenced from analytical techniques such as Transmission Electron Microscopy (TEM) and Powder X-Ray Diffraction (PXRD). The synthesized pyrazines exhibited photophysical , behaviour, displayed large stoke shift and explored as fluorescent probe for the sensitive as well as selective “turn-off” detection of iron with a limit of detection of 0.63 µM. The sensing method has also useful for the quantification of iron in spiked water samples. Furthermore, the application of luminescent pyrazine as fluorescent ink was successfully demonstrated.

中文翻译：

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磁性可重复使用的 Fe3O4-CuO 纳米颗粒作为合成芳基取代的荧光吡嗪的催化剂，用于 Fe 传感和墨水应用


摘要。使用高度稳定且可重复使用的铁氧体稳定铜纳米粒子 (Fe3O4-CuO) 作为催化剂，从容易获得的甲基芳基/杂芳基酮和 1,2-二胺合成取代吡嗪。该反应在氧气气氛下通过级联亚胺形成-氧化环化方法进行。透射电子显微镜 (TEM) 和粉末 X 射线衍射 (PXRD) 等分析技术证明，纳米催化剂很容易回收并重复使用最多三个连续循环，颗粒尺寸、催化活性和反应产率没有任何显着下降。合成的吡嗪表现出光物理行为，显示出大的斯托克位移，并探索作为荧光探针用于灵敏以及选择性“关闭”检测铁，检测限为 0.63 µM。该传感方法还可用于定量加标水样中的铁。此外，还成功论证了发光吡嗪作为荧光油墨的应用。