Microcrystal induced emission enhancement of a small molecule probe and its use for highly efficient detection of 2,4,6-trinitrophenol in water

• 来源期刊: 中国科学:化学（英文版）
• 年，卷（期）: 2018,（7）
• 页码范围: 857-862
• 页数: 6页
• 语种: 英文

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 (ALE) effect for forming a cubic-like microcrystal structure in THF-H2O 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× t0-7 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.