Department of Chemistry, University of Kalyani, Kalyani-741235, India.
Anal Methods. 2021 Feb 7;13(5):695-702. doi: 10.1039/d0ay02033h. Epub 2021 Jan 22.
Napthalimide-linked pyridylazo derivatives 1 and 2 have been designed and synthesized. Compound 1 acts as a gelator in DMF-HO (1 : 1, v/v). The brown gel is photostable and shows good viscoelastic properties. The value of G' is almost 10 times higher than that of G'' over the entire range of frequencies at a constant strain of 1%. The SEM image shows the presence of densely stacked flakes. In comparison, compound 2, devoid of free phenolic -OH, does not show gelation properties under identical conditions. However, the brown gel of 1 shows selective sensing of CN ions over a series of anions involving phase change through the deprotonation mechanism. While the brown gel of 1 is selectively ruptured in the presence of CN to the sol, compound 1 in solution shows measurable UV-vis and emission changes in the presence of CN over the other anions and validates the visual sensing of CN. In the test-kit application, the yellow paper strip turned into pinkish-red upon contact with CN.
萘酰亚胺连接的吡啶偶氮衍生物 1 和 2 已经被设计和合成。化合物 1 在 DMF-HO（1:1，v/v）中充当凝胶剂。棕色凝胶具有良好的光稳定性和黏弹性。在恒定应变 1%的情况下，在整个频率范围内，G'的值几乎是 G''的 10 倍。SEM 图像显示存在密集堆积的薄片。相比之下，化合物 2 缺乏游离的酚羟基，在相同条件下不显示凝胶性质。然而，1 的棕色凝胶表现出对 CN 离子的选择性传感，涉及通过去质子化机制的相变化。虽然 1 的棕色凝胶在存在 CN 时会选择性地破裂为溶液，但在存在 CN 的情况下，1 在溶液中的紫外可见和荧光变化是可测量的，超过其他阴离子，并验证了对 CN 的可视化传感。在测试试剂盒应用中，黄色纸条与 CN 接触后变成粉红色。
