AIMD‐Based Protocols for Modeling Exciplex Fluorescence Spectra and Inter‐System Crossing in Photocatalytic Chromophores

Journal of Computational Chemistry, Journal Year: 2025, Volume and Issue: 46(4)

Published: Feb. 4, 2025

This study introduces a computational protocol for modeling the emission spectra of exciplexes using excited-state ab initio molecular dynamics (AIMD) simulations. The is applied to model exciplex formed by oligo-p-phenylenes (OPPs) and triethylamine (TEA), which interest in context photocatalytic reduction CO2$$ {\mathrm{CO}}_2 $$ . AIMD facilitates efficient sampling conformational space OPP3 OPP4 with TEA, offering dynamic alternative previously employed static methods. AIMD-based successfully reproduces experimental OPP-TEA exciplexes, agreeing previous findings. results show that simulations provide an means these requiring less user input and, some instances, fewer resources than multiple optimizations initiated from user-specified initial structures. also evaluates yield intersystem crossing (ISC) Landau-Zener probability. suggest ISC minor decay channel OPP4. work provides new insights into structural flexibility characteristics photoredox catalyst systems, potentially contributing improved design strategies organic chromophores applications.

Language: Английский

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Comprehensive Insights into Exciplex Behavior in Nonpolar Media: Revisiting Weller’s Framework with Molecular Conformation

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

Published: March 28, 2025

Exciplexes are pivotal in organic light-emitting diodes and photovoltaics. However, their formation emission nonpolar solvents remain unclear. Revisiting Weller's works on photoinduced electron transfer (PET) rates exciplex based electrochemical redox potentials, we investigate behavior cyclohexane using anthracene (Ant) as an acceptor N,N-dimethylaniline (DMA) derivatives donors. Employing steady-state time-resolved spectroscopy, electrochemistry, density functional theory (DFT) calculations, demonstrate that potentials alone inadequately explain the environments. Our DFT analysis reveals C-N rotational angle of dimethylamine group a donor influences highest occupied molecular orbital (HOMO) energy levels, affecting quenching processes. Furthermore, time-dependent simulations accurately reproduce experimental spectra, linking intensity to contribution HOMO. These findings deepen understanding media provide insights for designing interpreting exciplex-based optoelectronic materials.

Language: Английский

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Calculating absorption and fluorescence spectra for chromophores in solution with ensemble Franck–Condon methods

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

Published: July 28, 2024

Accurately modeling absorption and fluorescence spectra for molecules in solution poses a challenge due to the need incorporate both vibronic environmental effects, as well necessity of accurate excited state electronic structure calculations. Nuclear ensemble approaches capture explicit Franck–Condon methods recently introduced ensemble-Franck–Condon combine advantages methods. In this study, we present analyze simulated generated with combined three chromophore–solvent systems compare them standard spectra, experiment. Employing configurations obtained from ground ab initio molecular dynamics, are directly compared each other assess accuracy relative computational time. We find that approach employing an average finite-temperature line shape generates nearly identical direct summation at one-fourth cost. how spectral simulation method, level theory, affects shapes associated Stokes shifts 7-nitrobenz-2-oxa-1,3-diazol-4-yl Nile red dimethyl sulfoxide 7-methoxy coumarin-4-acetic acid methanol. For first time, our studies show capability spectroscopy provide powerful tool simulating linear optical spectra.

Language: Английский

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Calculating Absorption and Fluorescence Spectra for Chromophores in Solution with Ensemble Franck-Condon Methods

Published: May 8, 2024

Accurately modeling absorption and fluorescence spectra for molecules in solution poses a challenge due to the need incorporate both vibronic environmental effects, as well necessity of accurate excited state electronic structure calculations. Nuclear ensemble approaches capture explicit Franck-Condon methods recently introduced ensemble-Franck-Condon combine advantages methods. In this study, we present analyze simulated generated with combined three chromophore-solvent systems compare them standard spectra, experiment. Employing configurations obtained from ground ab initio molecular dynamics, are directly compared each other assess accuracy relative computational time. We find that approach employing an average finite-temperature lineshape generates nearly identical direct summation at one-fourth cost. how spectral simulation method, level theory, affects lineshapes associated Stokes shifts 7-nitrobenz-2-oxa-1,3-diazol-4-yl (NBD) Nile Red dimethyl sulfoxide (DMSO), 7-methoxy coumarin-4-acetic acid (7MC) methanol. For first time, our studies showcase capability spectroscopy provide powerful tool simulating linear optical spectra.

Language: Английский

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Understanding the Key Factors for Photoinduced Radical Generation in Crystalline Triphenylamines Using Experiment and Machine Learning

The Journal of Physical Chemistry C, Journal Year: 2024, Volume and Issue: unknown

Published: Sept. 20, 2024

Language: Английский

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