Modeling MR-TADF Emitters: Excited-State Decay Rate Constants and Wave Function Descriptors DOI
Mariana T. do Casal,

Youssef Badawy,

Daniel Escudero

и другие.

The Journal of Physical Chemistry C, Год журнала: 2024, Номер 128(43), С. 18170 - 18181

Опубликована: Окт. 17, 2024

Multiresonance thermally activated delayed fluorescence (MR-TADF) emitters have gained popularity given their potential of attaining negligible singlet–triplet energy gaps, i.e., ΔEST, without hindering emission, thus increasing the reverse and direct intersystem crossing rates affecting fluorescence. This is achieved due to singlet triplet states' short-range charge transfer character (SRCT). Thus, obtaining quantitative information about SRCT would help develop new MR-TADF emitters. work studies three different families emitters: DOBOA, DiKTa, OQAO. First, we compute adiabatic ΔEST with four methods (TDA-CAM-B3LYP, STEOM-DLPNO-CCSD, ADC(2), SCS-CC2). Then, (kr), (kISC), rate constants. For kr, assessed effect levels approximations on calculations. We show that kr does not depend significantly harmonic models (adiabatic Hessian or vertical Hessian), coordinate systems, broadening widths. Moreover, Herzberg–Teller effects are for but main contribution kISC kRISC. The computed constants agree well experimental results. propose use two wave function descriptors, Qat LOCa, based 1-particle transition density matrix, which assigns amount centered atoms. these descriptors transitions: S0 → S1, T1, S1 T1. studied cases, independent choice electronic structure method optimal geometry. decreases increase T1 Qat, while increases an Qat. These trends showcase how values can act as guiding design small values.

Язык: Английский

On the Meaning of De‐Excitations in Time‐Dependent Density Functional Theory Computations DOI Creative Commons
Felix Plasser

Journal of Computational Chemistry, Год журнала: 2025, Номер 46(8)

Опубликована: Март 25, 2025

De-excitations play a prominent role within the mathematical formalism of time-dependent density functional theory (TDDFT) and other excited-state response methods. However, their physical meaning remains largely unexplored poorly understood. It is purpose this work to shed new light on issue. The main thesis developed here that de-excitations are not peculiarity TDDFT but they more fundamental property underlying wave functions reflecting how electrons excited between partially occupied orbitals. paraquinodimethane (pQDM) molecule chosen as convenient model system whose open-shell character can be modulated via twisting its methylene groups. Using one-electron transition matrix rigorous basis for our analysis, we highlight qualitative quantitative parallels in way reflected multireference function computations. As physically observable consequence, lowering dipole moment derives from destructive interference excitation de-excitation contributions. In summary, hope will formal practical aspects regarding application computations, especially diradicaloid systems.

Язык: Английский

Процитировано

0
Low-lying excited states of linear all-trans polyenes: the σ–π electron correlation and the description of ionic states DOI
Julio C. V. Chagas, Luan G. F. dos Santos, Reed Nieman

и другие.

Physical Chemistry Chemical Physics, Год журнала: 2025, Номер unknown

Опубликована: Янв. 1, 2025

Accurately describing ionic states requires addressing basis-set effects, size-extensivity errors, and, most importantly, σ–π electron correlation.

Язык: Английский

Процитировано

0
Classification and quantitative characterisation of the excited states of π-conjugated diradicals DOI Creative Commons

Lujo Matasović,

Hugo Bronstein, Richard H. Friend

и другие.

Faraday Discussions, Год журнала: 2024, Номер 254, С. 107 - 129

Опубликована: Янв. 1, 2024

Diradicals are of high current interest as emerging materials for next generation optoelectronic applications. To tune their excited-state properties it would be greatly beneficial to have a detailed understanding the wave functions different states involved but this endeavour is hampered by formal and practical barriers. tackle these challenges, we present analysis well concrete results on diradical excited states. We start with investigation available two-orbital two-electron model viewed from both valence-bond molecular orbital perspectives. highlight presence zwitterionic illustrate connections found in closed-shell molecules. Subsequently, introduce protocols analysing realistic multireference computations applying

Язык: Английский

Процитировано

1
Modeling MR-TADF Emitters: Excited-State Decay Rate Constants and Wave Function Descriptors DOI
Mariana T. do Casal,

Youssef Badawy,

Daniel Escudero

и другие.

The Journal of Physical Chemistry C, Год журнала: 2024, Номер 128(43), С. 18170 - 18181

Опубликована: Окт. 17, 2024

Multiresonance thermally activated delayed fluorescence (MR-TADF) emitters have gained popularity given their potential of attaining negligible singlet–triplet energy gaps, i.e., ΔEST, without hindering emission, thus increasing the reverse and direct intersystem crossing rates affecting fluorescence. This is achieved due to singlet triplet states' short-range charge transfer character (SRCT). Thus, obtaining quantitative information about SRCT would help develop new MR-TADF emitters. work studies three different families emitters: DOBOA, DiKTa, OQAO. First, we compute adiabatic ΔEST with four methods (TDA-CAM-B3LYP, STEOM-DLPNO-CCSD, ADC(2), SCS-CC2). Then, (kr), (kISC), rate constants. For kr, assessed effect levels approximations on calculations. We show that kr does not depend significantly harmonic models (adiabatic Hessian or vertical Hessian), coordinate systems, broadening widths. Moreover, Herzberg–Teller effects are for but main contribution kISC kRISC. The computed constants agree well experimental results. propose use two wave function descriptors, Qat LOCa, based 1-particle transition density matrix, which assigns amount centered atoms. these descriptors transitions: S0 → S1, T1, S1 T1. studied cases, independent choice electronic structure method optimal geometry. decreases increase T1 Qat, while increases an Qat. These trends showcase how values can act as guiding design small values.

Язык: Английский

Процитировано

1