A Probe Molecule Based on 1,3,4-Oxadiazole Constructed for Crystal Structure Analysis and Sn⁴⁺ Identification

In order to develop the application of 1,3,4-oxadiazole compounds in the direction of fluorescent probes, we modified the probes by introducing 2-(bromomethyl)pyridine on the amino group of 1,3,4-oxadiazole derivatives, and synthesized HL1(2-(5-(2-aminophenyl)-1,3,4-oxadiazol-2-yl)-N-(pyridin-2-ylmethyl)aniline). Its structure was characterized by NMR, HRMS and single crystal X-ray diffraction. The weak interaction of HL1 was analyzed by using Multiwfn to draw Hirshfeld surface. The HOMO and LUMO orbitals of HL1 were analyzed in B3LYP/6-311++G basis set using DFT theory. HL1 is highly selective to Sn⁴⁺ in ACN, LOD = 5.08∙10^–7 M, Ka = 1.73∙103M^–1.