摘要
In this contribution, we reported a very simple and small molecule material, 2,5-dimethoxyterephthalaldehyde(DMA). It exhibited a relatively weak fluorescence in solution, while showed a steadily increased green fluorescence with typical aggregation-induced enhanced emission(AIE) effect for forming a cubic-like microcrystal structure in THF-H2 O mixed solvent.The microcrystals presented significantly higher fluorescence than that of amorphous aggregates. The DMA microcrystals suspension showed a good response to 2,4,6-trinitrophenol(TNP) with a LOD of 1.2×10^(-7) M, which is the best result of TNP detection in aqueous solution. Quantum chemical calculation revealed that DMA is a donor(D)-receptor(A) type molecule with methoxy unit as donor and carbonyl moiety as receptor. Its emission arises from an intramolecular charge transfer(ICT) from methoxy units to carbonyl units. NMR indicated that there is a strong hydrogen bond interaction between DMA and TNP.Hydrogen bond interaction can effectively decrease the intermolecular distance of DMA and TNP, which will increase the efficiency of photoinduced electron transfer(PET) and fluorescence resonance energy transfer(FRET), and hence will be advantageous for its selectivity. The microcrystal induced enhanced emission could be generally used for kinds of target molecules analysis.
In this contribution, we reported a very simple and small molecule material, 2,5-dimethoxyterephthalaldehyde（DMA）. It exhibited a relatively weak fluorescence in solution, while showed a steadily increased green fluorescence with typical aggregation-induced enhanced emission（AIE） effect for forming a cubic-like microcrystal structure in THF-H2 O mixed solvent.The microcrystals presented significantly higher fluorescence than that of amorphous aggregates. The DMA microcrystals suspension showed a good response to 2,4,6-trinitrophenol（TNP） with a LOD of 1.2×10 （-7） M, which is the best result of TNP detection in aqueous solution. Quantum chemical calculation revealed that DMA is a donor（D）-receptor（A） type molecule with methoxy unit as donor and carbonyl moiety as receptor. Its emission arises from an intramolecular charge transfer（ICT） from methoxy units to carbonyl units. NMR indicated that there is a strong hydrogen bond interaction between DMA and TNP.Hydrogen bond interaction can effectively decrease the intermolecular distance of DMA and TNP, which will increase the efficiency of photoinduced electron transfer（PET） and fluorescence resonance energy transfer（FRET）, and hence will be advantageous for its selectivity. The microcrystal induced enhanced emission could be generally used for kinds of target molecules analysis.
基金
supported by the Ministry of Science and Technology (2016YFA0200800)
the National Natural Science Foundation of China (51473182, 61731016, 61771460)
the Youth Innovation Promotion Association of Chinese Academy of Sciences (2015190)
