Cooperativity of ESPT and Aggregation-Induced Emission Effects—An Experimental and Theoretical Analysis of a 1,3,4-Thiadiazole Derivative

International Journal of Molecular Sciences, Journal Year: 2024, Volume and Issue: 25(6), P. 3352 - 3352

Published: March 15, 2024

4-[5-(Naphthalen-1-ylmethyl)-1,3,4-thiadiazol-2-yl]benzene-1,3-diol (NTBD) was extensively studied through stationary UV–vis absorption and fluorescence measurements in various solvents solvent mixtures by first-principles quantum chemical calculations. It observed that while polar (e.g., methanol) only a single emission band emerged; the analyzed 1,3,4-thiadiazole derivative capable of producing dual signals low polarity n-hexane) certain methanol/water). As clearly follows from experimental spectroscopic studies theoretical modeling, specific characteristic NTBD is triggered effect enol → keto excited-state intramolecular proton transfer (ESIPT) case mixture reinforced aggregation thiadiazole molecules. Specifically, restriction rotation (RIR) due to environmental hindrance suppresses formation non-emissive twisted charge (TICT) excited keto* states. result, this particular simultaneously both ESIPT aggregation-induced (AIE).

Language: Английский

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Importance of Orbital Invariance in Quantifying Electron–Hole Separation and Exciton Size

Journal of Chemical Theory and Computation, Journal Year: 2024, Volume and Issue: 20(21), P. 9446 - 9463

Published: Oct. 16, 2024

A fundamental tenet of quantum mechanics is that properties should be independent representation. In self-consistent field methods such as density functional theory, this manifests a requirement invariant with respect to unitary transformations the occupied molecular orbitals and (separately) unoccupied orbitals. Various

Language: Английский

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Selecting the Optimal DFT Functionals for Reproducing the UV‐Vis Properties of Transition‐Metal Photocatalysts

Chemistry - Methods, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 20, 2025

Abstract We have applied our practice‐oriented TDDFT benchmark strategy to assess the performance of pure, hybrid, range‐separated hybrid and double‐hybrid functionals for reproducing electronic spectra a set 137 transition‐metal complexes. Our results enable simple pre‐screening new based photocatalysts. The reference data is on recently published measurements, from which we established database. database named TMPHOTCAT‐137 reflect number complexes (with Cu, Ru, Ir, Fe, Au, Mo W centres) included fact that all them are either proven or potential found M06 functional best performer both in terms practical accuracy consistency metals except Fe. While B3LYP similarly accurate Ru Ir complexes, rest significant wavelength scaling necessary. Compared previous organic photocatalysts, exhibit considerably poorer while range separated hybrids CAM−B3LYP ωB97X−D offer most consistent datasets. Among metals, iron proved be difficult TDDFT: even predicts singlet‐singlet absorption quintet ground states erroneously, especially weak ligand fields (i. e., only Fe−N bonds). do not this behaviour pure (GGA, meta‐GGA) functionals, but role HF exchange spectral prediction equivocal; with high amounts perform insufficiently, smaller amount exact yields overall better (M06, B3LYP). also shown inclusion spin‐orbit coupling heavier does improve results. updated spectrum optimizer code, Jupyter Notebook used analysis available at github.com/PeterF1234/spectrum_optimizer.

Language: Английский

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Computational and experimental study of terpolymers: spectroscopic, thermal, thermochemical, molecular property, and in silico toxicity analysis

Drug and Chemical Toxicology, Journal Year: 2025, Volume and Issue: unknown, P. 1 - 17

Published: Feb. 28, 2025

In this study, a comprehensive analysis of the CMA2OEM-co-DVB-co-AMPS (2-(bis(cyanomethyl)amino)-2-oxoethyl methacrylate-co-divinylbenzene-co-2-acrylamido-2-methyl-1-propanesulfonic acid) and CMA2OEM-co-DVB-co-VIM methacrylate-co-divinylbenzene-co-vinylimidazole) terpolymers was conducted. The structural chemical properties were examined using Fourier transform infrared (FT-IR) spectroscopy, frontier molecular orbital analysis, electrostatic potential (MEP) maps, 1H, 13C NMR thermochemistry surface maps (TCSM), toxicity assessments, physical properties, electron localization function (ELF), total (ESP) analyses. silico analyses, quantitative structure–activity relationship (QSAR) model used for Toxicity Estimation Software Tool (TEST) ProTox 3.0, web-based virtual laboratory, oral prediction. estimates TEST showed that both exhibited low profiles. Oral prediction emphasizes may pose greater risk compared to CMA2OEM-co-DVB-co-AMPS. addition, experimental thermal characterization these also performed. These analyses have provided significant insights into applications functional terpolymers.

Language: Английский

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Rational design and DFT-based study of non-fullerene acceptors for high-performance organic solar cells: End-cap and Core modifications for enhanced charge transfer

Computational and Theoretical Chemistry, Journal Year: 2025, Volume and Issue: unknown, P. 115209 - 115209

Published: March 1, 2025

Language: Английский

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Revisiting the Half-and-Half Functional

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

Published: April 21, 2025

Hybrid density functionals typically provide significantly better accuracy than semilocal functionals. Conventional wisdom holds that incorporating more 20-25% exact exchange is deleterious to thermochemical properties and should only be used as a last resort, for problems are dominated by self-interaction error. In such cases, the Becke-Lee-Yang-Parr "half-and-half" functional (BH&H-LYP) has emerged go-to choice, especially in time-dependent theory calculations excitation energies. Here, we examine assumption 50% Hartree-Fock sacrifices accuracy. Using sequence of B(α)LYP, with different percentages (0 ≤ α 100), find BH&H-LYP (with = 50) nearly optimal affords similar B3LYP thermochemistry, barrier heights, Although less accurate atomization energies, this emerges sole rationale taboo against values > 25. Overall, reasonable choice error, including charge-transfer complexes core-level While remains valence use appears an acceptable compromise, can without undue concern over its diminished ground-state properties.

Language: Английский

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Visible Light Induced Exciton Dynamics and trans-to-cis Isomerization in Azobenzene Aggregates: Insights from Surface Hopping/Semiempirical Configuration Interaction Molecular Dynamics Simulations

ACS Omega, Journal Year: 2024, Volume and Issue: unknown

Published: Feb. 9, 2024

Assemblies of photochromic molecules feature exciton states, which govern photochemical and photophysical processes in multichromophoric systems. Understanding the photoinduced dynamics assemblies requires nonadiabatic treatment involving multiple states numerous nuclear degrees freedom, thus posing a challenge for simulations. In this work, we address aggregates azobenzene, prototypical molecular switch, performing on-the-fly surface hopping calculations combined with semiempirical configuration interaction electronic structure augmented transition density matrix analysis to characterize evolution. Specifically, consider excitation azobenzene tetramers nπ* absorption band located visible (blue) part electromagnetic spectrum, extending our recent work on after ππ* corresponding ultraviolet region [Titov, J. Phys. Chem. C 2023, 127, 13678–13688]. We find that excitons, are initially strongly localized by ground-state conformational disorder, undergo further (very strong) localization during short-time photodynamics. This excited-state process is extremely ultrafast, occurring within first 10 fs observe virtually no transfer excitons manifold. However, may occur via secondary pathways or ground state. Moreover, quantum yields trans-to-cis isomerization reduced aggregated

Language: Английский

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Theoretical insights into dopamine photochemistry adsorbed on graphene-type nanostructures

Physical Chemistry Chemical Physics, Journal Year: 2024, Volume and Issue: 26(20), P. 14937 - 14947

Published: Jan. 1, 2024

The equilibrium geometry structures and light absorption properties of the dopamine (DA) dopamine-

Language: Английский

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Insights into Halogen-Induced Changes in 4-Anilinoquinazoline EGFR Inhibitors: A Computational Spectroscopic Study

Molecules, Journal Year: 2024, Volume and Issue: 29(12), P. 2800 - 2800

Published: June 12, 2024

The epidermal growth factor receptor (EGFR) is a pivotal target in cancer therapy due to its significance within the tyrosine kinase family. EGFR inhibitors like AG-1478 and PD153035, featuring 4-anilinoquinazoline moiety, have garnered global attention for their potent therapeutic activities. While pre-clinical studies highlighted significant impact of halogen substitution at C3'-anilino position on drug potency, underlying mechanism remains unclear. This study investigates influence (X = H, F, Cl, Br, I) structure, properties, spectroscopy halogen-substituted (TKIs) using time-dependent density functional methods (TD-DFT) with B3LYP functional. Our calculations revealed that did not induce changes three-dimensional conformation TKIs but led noticeable alterations electronic such as dipole moment spatial extent, impacting interactions binding site. UV-visible spectra show more TKI-X compounds typically shorter wavelengths, bromine's peak wavelength 326.71 nm hydrogen, lowest IC50 nM, shifting lambda max 333.17 nm, indicating correlation between potency spectral characteristics. Further analysis four lowest-lying conformers each TKI-X, along crystal structures from database, confirms most conformer often minimum structure one low-lying conformers. TKI-Cl TKI-Br exhibit larger deviations (RMSD > 0.65 Å) compared other < 0.15 Å), associated greater flexibility. Dipole moments correlate (ln(IC50 nM)), showing significantly higher (>8.0 Debye) both structures. Additionally, optical shifts blue structures, contrast TKI-X. suggests reporting can effectively probe changes.

Language: Английский

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A new parameterization of the DFT/CIS method with applications to core-level spectroscopy

The Journal of Chemical Physics, Journal Year: 2024, Volume and Issue: 161(4)

Published: July 25, 2024

Time-dependent density functional theory (TD-DFT) within a restricted excitation space is an efficient means to compute core-level energies using only small subset of the occupied orbitals. However, core-to-valence are significantly underestimated when standard exchange-correlation functionals used, which partly traceable systemic issues with TD-DFT's description Rydberg and charge-transfer excited states. To mitigate this, we have implemented empirically modified combination configuration interaction single substitutions (CIS) based on Kohn-Sham orbitals, known as "DFT/CIS." This semi-empirical approach well-suited for simulating x-ray near-edge spectra, it contains sufficient exact exchange model excitations yet retains DFT's low-cost dynamical electron correlation. Empirical corrections matrix elements enable semi-quantitative simulation spectra without need significant posteriori shifts; this should be useful in complex molecules materials multiple overlapping edges. Parameter optimization use specific range-separated hybrid makes black-box method intended both core valence spectroscopy. Results herein demonstrate that realistic K-edge absorption emission can obtained second- third-row 3d transition metals, promising results L-edge well. DFT/CIS calculations require absolute shifts considerably smaller than what typical TD-DFT.

Language: Английский

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