Stimuli-responsive luminogens with aggregation-induced emission and excited state intramolecular proton transfer (ESIPT) properties have applications in storage devices, anti-counterfeiting, imaging, and sensors. Nevertheless, group rotation appears in twisted intramolecular charge transfer (TICT) state, resulting in decreased fluorescence intensity. Inhibiting TICT remains a challenge based on their intrinsic molecular configuration. Herein, we present a simple facile pressure-induced method to restrict the TICT behavior. Steady-state spectroscopy measurement shows that fluorescence enhancement and color shifts can be achieved under high pressure. Combined with in situ high-pressure ultrafast spectroscopy and theoretical calculations, the TICT behavior was restricted in two aspects. The ESIPT process was damaged, hence more particles stored in the E* state, and transferred to the TICT state hardly. Also, the rotation of (E)-dimethyl5-((4-(diethylamino)-2-hydroxybenzylidene)amino)isophthalate (SBOH) was restricted, significantly increasing the fluorescence intensity. This approach provides a new strategy for the development of stimulus-responsive materials.
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http://dx.doi.org/10.1016/j.saa.2023.122551 | DOI Listing |
Molecular rotor-based fluorophores (RBFs) that are target-selective and sensitive to both polarity and viscosity are valuable for diverse biological applications. Here, we have designed next-generation RBFs based on the underexplored bimane fluorophore through either changing in aryl substitution or varying π-linkages between the rotatable electron donors and acceptors to produce red-shifted fluorescence emissions with large Stokes shifts. RBFs exhibit a twisted intramolecular charge transfer mechanism that enables control of polarity and viscosity sensitivity, as well as target selectivity.
View Article and Find Full Text PDFBioorg Chem
January 2025
Key Laboratory for Tibet Plateau Phytochemistry of Qinghai Province, College of Pharmacy, Qinghai Minzu University, Xining 810007 Qinghai, China; State Key Laboratory of Applied Organic Chemistry and College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, China. Electronic address:
Viscosity is a fundamental property in biological systems, influencing organelle function and molecular diffusion. Abnormal viscosity is associated with diseases such as metabolic disorders, neurodegeneration, and cancer. Lysosomes, central to cellular degradation and recycling, are sensitive to viscosity changes, which can disrupt enzymatic activity and cellular homeostasis.
View Article and Find Full Text PDFJ Phys Chem A
January 2025
Advanced Membranes and Porous Materials Center, Division of Physical Science and Engineering, King Abdullah University of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia.
Understanding how structural modifications affect the photophysics of organic linkers is crucial for their integration into metal-organic frameworks (MOFs) for light-driven applications. This study explores the impact of varying the amine functional group position on two terephthalic acid derivatives─linker and linker ─by investigating their photophysics through a combination of steady-state and ultrafast laser spectroscopy and time-dependent density functional theory (TD-DFT) calculations. With tetrahydrofuran as the solvent, time-correlated single-photon counting revealed a 2-fold increase in the S excited-state lifetime of the molecule with the amine group at the meta position compared with that of the molecule with the amine group at the ortho position.
View Article and Find Full Text PDFChemistry
December 2024
Department of Nephrology, Children's Hospital of Chongqing Medical University, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing Key Laboratory of Pediatric Metabolism and Inflammatory Diseases, Chongqing, 400042, China.
In this study, a supramolecular fluorescent material was constructed by using double-cavity twisted cucurbit[14]uril (tQ[14]) and positively charged Astrazon Pink FG (APFG) based on the non-covalent host-guest interaction for the first time. The thermodynamic parameters of the APFG@tQ[14] in aqueous solution were determined by isothermal titration calorimetry (ITC), the results indicated that the spontaneous assembly of APFG@tQ[14] is mainly driven by enthalpy. The intramolecular charge transfer (ICT) effect induced the APFG@tQ[14] probe to emit a strong orange-red fluorescence.
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
January 2025
Instituto de Ciencia de Materiales de Madrid (ICMM), CSIC, Cantoblanco, 28049 Madrid, Spain; Departamento de Química Orgánica y Química Inorgánica, Universidad de Alcalá, 28805 Alcalá de Henares, Madrid, Spain. Electronic address:
7,7'-Diazaisoindigos are π-conjugated compounds but with poor luminescence properties. Their poor luminescence is generally attributed to the twisting around the central C-C bond in the excited state which favors non-radiative decay. We have found an unusual high fluorescence quantum yield (Φ ≈ 15 %) in a N,N‑Octyl-7,7'-diazaisoindigo derivative incorporating two triphenylamine (TPA) subunits at 5,5'-positions (called compound 12).
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