丙二腈与 6-羟基-2-萘甲醛反应合成 2-(6-羟基萘-2-亚甲基)丙二腈（探针1），并将其作为荧光探针用于检测氟离子。在测试体系中，探针1的二甲基亚砜（DMSO）溶液为浅黄色，几乎没有荧光；加入氟离子后，溶液颜色立刻变为粉红色，且溶液显示蓝色荧光；而加入其他阴离子，溶液未显示荧光。研究还发现探针1对氟离子具有较强的选择性和较高的灵敏度；Job’s法得出探针1与氟离子之间的配比为1∶1；核磁滴定结果表明：加入氟离子后，探针1上的酚羟基发生去质子化反应；分子轨道理论计算得出，探针1去质子化后HOMO-LUMO能级差增大，明显改变了溶液颜色和荧光光谱。

2-(6-hydroxynaphthalen-2-methylene) malononitrile (probe 1) was synthesized by means of the reaction of malononitrile and 6-hydroxy-2-naphthaldehyde, and the product was used as a fluorescent probe for the detection of fluoride ions. The results show that, in the detection system, the DMSO solution of probe 1 is pale yellow without fluorescence, and it immediately turns to be pink with blue-fluorescence after adding fluoride ions but shows no fluorescence after adding other anions. It is also found that probe 1 exhibits a strong selectivity and a high sensitivity to fluoride ions. According to the evaluation of the Job’s plot, the ratio of probe 1 to fluoride ions in the complex is found to be 1:1. The 1H NMR titration results confirm that the deprotonation of phenolic hydroxyl of probe 1 occurs after adding fluoride ions. The calculation results based on the Frontier molecular orbital theory indicate that, after the deprotonation of probe 1, its HOMO–LUMO energy gap increases, and the solution color and the fluorescence spectrum change dramatically.