Two pyridinium amide-based receptors L1 and L2 with a small difference of H-bond position of the amide have been synthesized and characterized. Interestingly, they exhibited a huge difference in sensing towards AcO- and H2PO4 -, respectively. Receptor L1 was found to be ‘naked-eye’ selective for AcO- anions, while receptor L2 showed clear fluorescence enhancement selective to H2PO4 - anion. The recognition ability has been established by fluorescence emission, UV-vis spectra, and 1HNMR titration.

中文翻译：

---

H键位置发生细微变化的两个基于吡啶的酰胺基受体对阴离子的传感特性的差异

合成并表征了两个基于吡啶鎓酰胺的受体L1和L2，酰胺的H键位置相差很小。有趣的是，它们分别表现出对AcO-和H2PO4-的巨大差异。发现受体L1对AcO-阴离子具有“裸眼”选择性，而受体L2对H2PO4-阴离子则具有明显的荧光增强作用。通过荧光发射，紫外可见光谱和1HNMR滴定建立了识别能力。