Ingeniously regulating the conformational equilibrium and ESPT mechanism of HBT-DPI by solvent environment: A novel perspective

Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy, Journal Year: 2025, Volume and Issue: 330, P. 125739 - 125739

Published: Jan. 10, 2025

Language: Английский

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Deciphering the Photophysical Properties of Nonplanar Heterocyclic Compounds in Different Polarity Environments

The Journal of Physical Chemistry B, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 15, 2025

Nonplanar (butterfly-shaped) phenothiazine (PTZ) and its derivative's (M-PTZ) photophysical spectral properties have been tuned by varying the solvents their polarity investigated employing spectroscopic techniques such as UV-Vis, steady-state time-resolved fluorescence, TDDFT calculations. The UV-Vis absorption studies calculations reveal two distinct bands for both compounds: a strong π-π* transition at shorter wavelengths weaker n-π* transition, which displays little bathochromic shift in polar solvents. detailed emission that dual is result of photoinduced excited-state conjugation enhancement (ESCE) process. band wavelength corresponds to locally excited (LE) state, while longer arises from planarized state resulting ESCE. With increase solvent polarity, LE less affected, whereas positive solvatochromism observed ESCE band. As increases, demonstrates significant solvatochromism, intensity decreases with higher suggesting stabilization state. biexponential decay fluorescence lifetimes further corroborates behavior PTZ M-PTZ. exhibits photoluminescence quantum yield (PLQY) than M-PTZ, viscosity influences PLQY, indicating nonradiative activated during planarization also known enhancement. Furthermore, (time-dependent) density functional theory (TD) DFT performed understand geometrical parameters electronic transitions these model molecules corroborate experimental findings. These findings underscore influence molecular structure on dynamics eventually hold substantial implications advanced applications.

Language: Английский

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Theoretical study on the conformation-dependent charge transfer of the excited state of dopamine

Heliyon, Journal Year: 2025, Volume and Issue: 11(2), P. e42058 - e42058

Published: Jan. 1, 2025

Clarifying the relationship between conformation and charge transfer is crucial for understanding functional mechanisms of molecules in organisms. Theoretical calculations dopamine, N,N-dimethyldopamine, N,N-dihydroxydopamine were related to transfer, excited state was clearly characterized. First, stable configuration ground molecule optimized, potential energy ionic scanned select all conformations, except chiral problem. Subsequently, CAM-B3LYP/aug-cc-pVTZ method used excite molecule, excitation types first five states discussed. Finally, calculated, different conformations analyzed detail. Through it has been speculated that dopamine exist a coiled an organism interact with water form N,N-dihydroxydopamine, or hydrogen bonds better information transmission.

Language: Английский

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Influence of Solvents and Halogenation on ESIPT of Benzimidazole Derivatives for Designing Turn-on Fluorescence Probes

ACS Omega, Journal Year: 2024, Volume and Issue: 9(20), P. 22102 - 22111

Published: May 10, 2024

This work reports a theoretical investigation of the solvent polarity as well halogenation benzimidazole derivatives during excited state intramolecular proton transfer (ESIPT). It details how environment and halogen substitution may contribute to efficiency ESIPT upon keto-enol tautomerism exploits this effect design fluorescence sensing. For purpose, we first examine conformational equilibrium containing different atoms, which results in transfer, using density-functional theory (DFT) combined with polarizable continuum model (PCM). Then evaluate dielectric constants within time-dependent DFT (TD-DFT) approaches. Our quantitatively allow determination large Stokes shifts nonpolar solvents around 100 nm. These are agreement experimental solvatochromism studies benzimidazoles. The halogenation, fluorine, chlorine, bromine, is less important than polarization when takes place. Thus, can be properly chosen depending on interest synthesis benzimidazole-based turn-on appropriate solvents.

Language: Английский

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Close-packed small nanocubes assemblies as efficient SERS substrates

Journal of Molecular Structure, Journal Year: 2023, Volume and Issue: 1294, P. 136441 - 136441

Published: Aug. 18, 2023

Language: Английский

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