Study On Fluorescent Probes And Optical Materials On Basis Of Novel Molecules With Aggregation-induced Emission Enhancement Properties

In this dissertation, a series of salicylaldehyde hydrazone (SH) derivativeswere synthesized by condensing salicylaldehyde and amine compounds withease-preparation and low-cost. Intramolecular H-bonds of salicylaldiminemoieties allowed the nonradiative intramolecular rotation of two planarπ-conjugated moieties only around N-N or C-N single bond when moleculeswere dissolved in solvents. Therefore, potential aggregation-induced emissionenhancement (AIEE) properties of SH derivatives could be promised by therestriction of free intramolecular rotation in aggregate/solid state.Structure-property relationships of SH derivatives were utilized to constructfluorescence detecting systems and organic optical materials on basis of AIEE effect. Inthe respect of fluorescence detecting system, facile methods for the determination ofhydrazine and protamine have been developed based on fluorescence turn-on effect ofaggregate production; the limit of detection (LOD) of hydrazine in EtOH/HAc/H2O(30/4/66) was80nM, and that for protamine in buffer solution (pH=9.16) was43ng/mL. Also, an SH immobilized hybrid mesoporous materials with AIEE propertieswas prepared, and further utilized as a solid fluorescent sensor for reproducibledetection of Cu(II) ions based on fluorescence-off signal, with an LOD of0.8μM inbuffer solution (pH=5.3). The above three methods are with short response time, highselectivity and sensitivity, and could be used for detecting practical samples. On theother hand, two kinds of organic optical material with AIEE properties were prepared:firstly, a series of salicylaldimine crystals with color/morphology tunable propertieswere obtained by changing substituents; secondly, a crystalline solid of salicylaldehydeazine derivative with switchable solid-state fluorescence in responsible to externalthermal and piezochromic stimulus was obtained, which resulted from two distinctivecrystalline lattices via different π-π interactions. The facile synthesis andcrystal-preparing procedures favors the further theoretic exploration and practical use.