Synthesis And Application Of Compounds Derived From Two Aldehyde Groups For Detection Of Water Or Copper Ions

The aggregation-induced emission(AIE) is a phenomenon that compounds were non-emissive or weakly fluorescent in dilute solutions but can emit strong fluorescence in solutions with high concentration or in solid film. Most of fluorescent molecules have the characteristics of aggregation-caused quenching(ACQ), which is not conducive to the detection. In contrast, AIE can solve this shortcoming and has attracted the attention of scientists, and has been widely used in the fields of chemical sensors, optical materials and so on.In this thesis, we designed and synthesized an organic small molecule-based fluorescent probe with AIE property for the detection of water in organic solvent. The probe is soluble well in most of the organic solvents shows weak blue fluorescence. The presence of water in the organic solvent trigger the molecule to aggregate through the intermolecular hydrogen bond between water and the aldehyde groups of the probe, leading to the fluorescence enhancement of the probe. There is a good linear relationship between the fluorescence intensity and water content in organic solvents, providing a method for quantitative detection of water in organic solvents. More importantly, the probe can detect water content in most organic solvents with high sensitivity, and the detection limit is as low as 0.5%. In addition, the probe can quantify the water content with a wide range, where even more than 10% of water content in organic solvents can be quantitatively detected.Based on the mechanism of the probe for detection of water, we prepared the test papers with the probe. The test papers show weak blue emission upon excitation with UV lamp due to the low aggregation degree of the probe molecules in the test papers. When water was sprayed on the test paper, high-resolution fluorescence images and text were obtained, proving that the test paper can be used for ink jet printing. In addition, utilizing the fact that the main component of fingers sweat secretion is water, the papers were successfully used for fingerprint.By using the material with two aldehyde groups, we also synthesized a Schiff base for detection of copper ion(II). Upon addition of 8 equivalents of copper ion(II), the Schiff base compound showed 180 times enhancement of fluorescence intensity at 439 nm with a low fluorescence background in a mixed system of acetonitrile and phosphate buffer. From 3 to 6 equivalents of copper ion(II), there is a good linear relationship between the fluorescence intensity of this compound and the concentration of copper ion(II). The compound can detect the copper ions(II) quantitatively with high specificity and high sensitivity, which overcomes the shortcomings of the copper ion(II) probes with on-off fluorescence response.