Cross-dehydrogenative coupling (CDC) efficiently constructs complex organic molecules by directly coupling two C-H bonds from different substrates. This enables the functionalisation of existing chromophores with different substituents, facilitating efficient sensor development. Electronically diverse C-3 sulfenylated 2-phenyl-4-pyrido[1,2-]pyrimidin-4-ones were synthesised using iodine mediated CDC protocol and structurally characterised using FT-IR, H and C NMR and mass spectrometry technique. Single crystal X-ray diffraction technique was utilised for establishing the molecular structure of . The absorption and emission intensity for all the synthetics were recorded in the range of 365-375 and 406-509 nm, respectively in solvents of varying polarity. Compound , with distinct dispersion of the frontier molecular orbitals due to ring extension, showed exceptional absorption and emission intensity in water and methanol. All the sensing applications of were investigated using water/methanol (1:4; ) as the solvent system. An abrupt increase in the absorption intensity with a decrease in emission maxima of was observed upon Fe(NO).9HO addition. A detection limit of 1.27 × 10 M, low response time and thermal stability served as some of the characteristic features which established the probe as a potential sensor for Fe ion. Further, the stoichiometry and binding constant of the complex was determined by Benesi-Hildebrand and Job's plot.

中文翻译：

---

合理设计的 C-3 磺基化 2-苯基-4H-吡啶并[1,2-a]嘧啶-4-酮荧光探针用于识别 Fe3+


交叉脱氢偶联 (CDC) 通过直接偶联来自不同底物的两个 CH 键，有效构建复杂的有机分子。这使得现有发色团能够具有不同取代基的功能化，从而促进高效的传感器开发。使用碘介导的 CDC 方案合成了电子多样化的 C-3 磺基化 2-苯基-4-吡啶并[1,2-]嘧啶-4-酮，并使用 FT-IR、H 和 C NMR 和质谱技术进行结构表征。利用单晶X射线衍射技术建立了分子结构。在不同极性的溶剂中，所有合成物的吸收和发射强度分别在 365-375 和 406-509 nm 范围内记录。化合物由于环延伸而具有明显的前沿分子轨道分散性，在水和甲醇中表现出异常的吸收和发射强度。所有传感应用均使用水/甲醇（1:4；）作为溶剂系统进行研究。添加 Fe(NO).9H2O 后，观察到吸收强度突然增加，发射最大值降低。 1.27 × 10 M 的检测限、低响应时间和热稳定性是该探针作为铁离子潜在传感器的一些特征。此外，复合物的化学计量和结合常数通过Benesi-Hildebrand和Job's图确定。