| 研究実績の概要 |
Organic fluorescent dyes have received a great notice as luminescent materials for organic ELs, sensors, probes, dye lasers and so on. In recent years, Aggregation Induced Emission (AIE) has been reported as a unique phenomenon that enhances the luminescence intensity due to aggregation of dyes. In this study, we examined the fluorescence behavior of AIE molecules such as cyanine derivatives (DASMs) on the clay surface (S-FIE) in addition to the observation of AIE behavior in the poor solvents. The substituent effect on fluorescence behavior for AIE and S-FIE was also investigated. The absorption spectra were observed for sample where dye loadings are 2~150% vs cation exchange capacity (CEC) of the clay. DASMs adsorbed as a monomer state on clay up to ca. 25% vs. CEC. One of the 3 states (component 1) showed a strong emission enhancement compared to it without clay, as shown in Fig. 3 (S-FIE). As a result, Fluorescence increased not only for unsubstituted DASM but also for Me-DASM and Et-DASM (DASM: 29 times, Me-DASM: 160 times and Et-DASM: 110 times). These indicate that S-FIE phenomenon is not restrained by molecular structures if the molecule adsorbs on the clay surface in a monomer state. While the effect of AIE on the fluorescence enhancement strongly depends on the molecule’s structure, that of S-FIE sample is not restricted by the molecule’s structure. Furthermore, because the mechanism of S-FIE is relatively clear, S-FIE is easy to be predicted.
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