Scholarlink

<p>A new donor–π–acceptor (D–π–A) fluorescent chromophore incorporating an indole–pyrazole donor framework and an electron-accepting unit, 2-(3-cyano-4,5,5-trimethylfuran-2(5<i>H</i>)-ylidene)malononitrile (TCF) was designed. Various active-methylene compounds were also incorporated into the indole-pyrazole donor units to explore the substrate scope of the reaction. The molecular structure was confirmed by spectroscopic techniques, including NMR, FT-IR, and high-resolution mass spectrometry. Their photophysical properties were investigated using UV–Vis absorption and fluorescence spectroscopy in solution, aggregated media, and the solid state. The D–π–A system exhibited weak fluorescence in dilute solution but showed a pronounced aggregation-induced emission/enhancement (AIE/AIEE) effect upon increasing the water fraction in DMSO–water mixtures, accompanied by significantly enhanced fluorescence quantum yields and intense solid-state emission. The enhanced emission is attributed to restricted intramolecular motion in the aggregated state, while efficient intramolecular charge transfer arising from the donor–acceptor framework contributes to their fluorescence behavior. Density functional theory (DFT) calculations on Indole-Pyrazole Donor-Acceptor compounds (IPDA-1 to IPDA-5) further elucidated their electronic structures and supported the experimental photophysical observations. These combined experimental and theoretical results demonstrate that the indole–pyrazole-based D–π–A architecture is an effective molecular platform for developing aggregation-induced emissive luminogens with enhanced solid-state fluorescence and improved quantum yield in the aggregated state highlighting the potential of the synthesized D–π–A fluorophore as a promising candidate for future functional fluorescent materials.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Design, and Synthesis of Donor–π–Acceptor (D–π–A) Heterocyclic Compounds Exhibiting Aggregation-Induced Emission (AIE/AIEE) and Solid-State Emission

  • 期刊论文

  • 发表日期：

    2026年7月27日

查看全文
  • Thangjam Linda Devi,
  • Mayanglambam Maneeta Devi,
  • Francis A. S. Chipem,
  • Okram Mukherjee Singh

摘要

A new donor–π–acceptor (D–π–A) fluorescent chromophore incorporating an indole–pyrazole donor framework and an electron-accepting unit, 2-(3-cyano-4,5,5-trimethylfuran-2(5H)-ylidene)malononitrile (TCF) was designed. Various active-methylene compounds were also incorporated into the indole-pyrazole donor units to explore the substrate scope of the reaction. The molecular structure was confirmed by spectroscopic techniques, including NMR, FT-IR, and high-resolution mass spectrometry. Their photophysical properties were investigated using UV–Vis absorption and fluorescence spectroscopy in solution, aggregated media, and the solid state. The D–π–A system exhibited weak fluorescence in dilute solution but showed a pronounced aggregation-induced emission/enhancement (AIE/AIEE) effect upon increasing the water fraction in DMSO–water mixtures, accompanied by significantly enhanced fluorescence quantum yields and intense solid-state emission. The enhanced emission is attributed to restricted intramolecular motion in the aggregated state, while efficient intramolecular charge transfer arising from the donor–acceptor framework contributes to their fluorescence behavior. Density functional theory (DFT) calculations on Indole-Pyrazole Donor-Acceptor compounds (IPDA-1 to IPDA-5) further elucidated their electronic structures and supported the experimental photophysical observations. These combined experimental and theoretical results demonstrate that the indole–pyrazole-based D–π–A architecture is an effective molecular platform for developing aggregation-induced emissive luminogens with enhanced solid-state fluorescence and improved quantum yield in the aggregated state highlighting the potential of the synthesized D–π–A fluorophore as a promising candidate for future functional fluorescent materials.