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Woon K, Nikishau PA, Sini G. Fast and Accurate Determination of the Singlet–Triplet Gap in Donor–Acceptor and Multiresonance TADF Molecules by Using Hole–Hole Tamm–Dancoff Approximated Density Functional Theory. ADVANCED THEORY AND SIMULATIONS 2022. [DOI: 10.1002/adts.202200056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Kai‐Lin Woon
- Institute of Advanced Studies CY Cergy Paris Université 33 Bd du Port Cergy‐Pontoise 95000 France
- Low Dimensional Materials, Department of Physics University of Malaya Kuala Lumpur 50603 Malaysia
| | - Pavel A. Nikishau
- Research Institute for Physical Chemical Problems of the Belarusian State University 14 Leningradskaya st. Minsk 220006 Belarus
| | - Gjergji Sini
- Institute of Advanced Studies CY Cergy Paris Université 33 Bd du Port Cergy‐Pontoise 95000 France
- Laboratoire de Physico‐Chimie des Polymères et des Interfaces (LPPI) CY Cergy Paris Université 33 Bd du Port Cergy‐Pontoise 95000 France
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2
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Ivanova G, Bozova N, Petkov N, An C, Hu B, Mutovska M, Konstantinov K, Zagranyarski Y, Videva V, Yordanova A, Baumgarten M, Ivanova A. Benchmarking of Density Functionals for the Description of Optical Properties of Newly Synthesized π-Conjugated TADF Blue Emitters. Chemistry 2022; 28:e202104411. [PMID: 35107870 DOI: 10.1002/chem.202104411] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Indexed: 11/10/2022]
Abstract
Computational modeling of the optical characteristics of organic molecules with potential for thermally activated delayed fluorescence (TADF) may assist markedly the development of more efficient emitting materials for organic light-emitting diodes. Recent theoretical studies in this area employ mostly methods from density functional theory (DFT). In order to obtain accurate predictions within this approach, the choice of a proper functional is crucial. In the current study, we focus on testing the performance of a set of DFT functionals for estimation of the excitation and emission energy and the excited singlet-triplet energy gap of three newly synthesized compounds with capacity for TADF. The emitters are designed specifically to enable charge transfer by π-electron conjugation, at the same time possessing high-energy excited triplet states. The functionals chosen for testing are from various groups ranging from gradient-corrected through global hybrids to range-separated ones. The results show that the monitored optical properties are especially sensitive to how the long-range part of the exchange energy is treated within the functional. The accurate functional should also be able to provide well balanced distribution of the π-electrons among the molecular fragments. Global hybrids with moderate (less than 0.4) share of exact exchange (B3LYP, PBE0) and the meta-GGA HSE06 are outlined as the best performing methods for the systems under study. They can predict all important optical parameters correctly, both qualitatively and quantitatively.
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Affiliation(s)
- Georgia Ivanova
- Faculty of Chemistry and Pharmacy, University of Sofia, 1 James Bourchier blvd., 1164, Sofia, Bulgaria
| | - Nadezhda Bozova
- Faculty of Chemistry and Pharmacy, University of Sofia, 1 James Bourchier blvd., 1164, Sofia, Bulgaria
| | - Nikolay Petkov
- Faculty of Chemistry and Pharmacy, University of Sofia, 1 James Bourchier blvd., 1164, Sofia, Bulgaria
| | - Cunbin An
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany
| | - Benlin Hu
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany
| | - Monika Mutovska
- Faculty of Chemistry and Pharmacy, University of Sofia, 1 James Bourchier blvd., 1164, Sofia, Bulgaria
| | - Konstantin Konstantinov
- Faculty of Chemistry and Pharmacy, University of Sofia, 1 James Bourchier blvd., 1164, Sofia, Bulgaria
| | - Yulian Zagranyarski
- Faculty of Chemistry and Pharmacy, University of Sofia, 1 James Bourchier blvd., 1164, Sofia, Bulgaria
| | - Vladimira Videva
- Faculty of Chemistry and Pharmacy, University of Sofia, 1 James Bourchier blvd., 1164, Sofia, Bulgaria.,Institute of Optical Materials and Technologies, Bulgarian Academy of Sciences, 1113, Sofia, Bulgaria
| | - Adelina Yordanova
- Faculty of Chemistry and Pharmacy, University of Sofia, 1 James Bourchier blvd., 1164, Sofia, Bulgaria
| | - Martin Baumgarten
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany
| | - Anela Ivanova
- Faculty of Chemistry and Pharmacy, University of Sofia, 1 James Bourchier blvd., 1164, Sofia, Bulgaria
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Alipour M, Izadkhast T. Do any types of double-hybrid models render the correct order of excited state energies in inverted singlet–triplet emitters? J Chem Phys 2022; 156:064302. [DOI: 10.1063/5.0077722] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Mojtaba Alipour
- Department of Chemistry, School of Science, Shiraz University, Shiraz 71946-84795, Iran
| | - Tahereh Izadkhast
- Department of Chemistry, School of Science, Shiraz University, Shiraz 71946-84795, Iran
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Bas EE, Ulukan P, Monari A, Aviyente V, Catak S. Photophysical Properties of Benzophenone-Based TADF Emitters in Relation to Their Molecular Structure. J Phys Chem A 2022; 126:473-484. [PMID: 35061385 PMCID: PMC8895462 DOI: 10.1021/acs.jpca.1c08320] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Thermally activated delayed fluorescence (TADF) materials are commonly used in various apparatus, including organic light-emitting device-based displays, as they remarkably improve the internal quantum efficiencies. Although there is a wide range of donor-acceptor-based compounds possessing TADF properties, in this computational study, we investigated TADF and some non-TADF chromophores, containing benzophenone or its structural derivatives as the acceptor core, together with various donor moieties. Following the computational modeling of the emitters, several excited state properties, such as the absorption spectra, singlet-triplet energy gaps (ΔEST), natural transition orbitals, and the topological ΦS indices, have been computed. Along with the donor-acceptor torsion angles and spin-orbit coupling values, these descriptors have been utilized to investigate potential TADF efficiency. Our study has shown that on the one hand, our photophysical/structural descriptors and computational methodologies predict the experimental results quite well, and on the other hand, our extensive benchmark can be useful to pinpoint the most promising functionals and descriptors for the study of benzophenone-based TADF emitters.
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Affiliation(s)
- Ekin Esme Bas
- Department of Chemistry, Bogazici University, Bebek, 34342 Istanbul, Turkey
| | - Pelin Ulukan
- Department of Chemistry, Bogazici University, Bebek, 34342 Istanbul, Turkey
| | - Antonio Monari
- Université de Lorraine and CNRS, LPCT UMR 7019, F54000 Nancy, France.,Université de Paris and CNRS, ITODYS, F75006 Paris, France
| | - Viktorya Aviyente
- Department of Chemistry, Bogazici University, Bebek, 34342 Istanbul, Turkey
| | - Saron Catak
- Department of Chemistry, Bogazici University, Bebek, 34342 Istanbul, Turkey
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Alipour M, Karimi N. Spin-Opposite-Scaled Range-Separated Exchange Double-Hybrid Models (SOS-RSX-DHs): Marriage Between DH and RSX/SOS-RSX Is Not Always a Happy Match. J Chem Theory Comput 2021; 17:4077-4091. [PMID: 34085815 DOI: 10.1021/acs.jctc.1c00271] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The range-separated version of double-hybrid density functional theory (DH-DFT) with a remarkable efficiency for both ground-state and excited-state characteristics has recently come into spotlight. In this work, based on theoretical arguments, several variants of spin-opposite-scaled range-separated exchange double-hybrid models (SOS-RSX-DHs) have been proposed and validated. More specifically, we first extend the RSX-DHs to design some other related models. Next, the SOS version of the resulting approximations is constructed and thoroughly evaluated using standard benchmark compilations of various properties. It is shown that although there are properties for which the RSX-DH and SOS-RSX-DH frameworks are rival, there are still some problems particularly prone to the self-interaction error issues where our proposed models seem to be beneficial. Furthermore, some of the presented models devoid of any additional corrections can also surpass the recently proposed approximations from different rungs of "Jacob's Ladder". Nonetheless, perusing the results of different methods and detailed comparisons with the predecessors discloses that all things may not necessarily be well with the RSX and SOS-RSX schemes, where the parent DHs as well as their SOS counterparts can still come into play.
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Affiliation(s)
- Mojtaba Alipour
- Department of Chemistry, School of Science, Shiraz University, Shiraz 71946-84795, Iran
| | - Niloofar Karimi
- Department of Chemistry, School of Science, Shiraz University, Shiraz 71946-84795, Iran
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6
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Rodriguez-Serrano A, Dinkelbach F, Marian CM. Intersystem crossing processes in the 2CzPN emitter: a DFT/MRCI study including vibrational spin-orbit interactions. Phys Chem Chem Phys 2021; 23:3668-3678. [PMID: 33527934 DOI: 10.1039/d0cp06011a] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Multireference quantum chemical calculations were performed in order to investigate the (reverse) intersystem crossing ((R)ISC) mechanisms of 4,5-di(9H-carbazol-9-yl)-phthalonitrile (2CzPN). A combination of density funcional theory (DFT) and multireference configuration interaction methods (MRCI) was used. The excellent agreement of the computed absorption spectrum with available experimental absorption spectra lends confidence to the chosen computational protocol. Vertically, two triplet excited states (T1 and T2) are found below the S1 state. At the excited state minima, the calculated adiabatic energies locate only the T1 state below the S1 state. The enhanced charge transfer (CT) character of the geometrically relaxed excited states causes their mutual (direct) spin-orbit coupling (SOC) interaction to be low. Contributions of vibronic SOC to the (R)ISC probability, evaluated by a Herzberg-Teller-like procedure for a temperature of 300 K, are small but not negligible. For ISC, the S1→ T1 channel is the fastest (8 × 106 s-1), while the S1→ T2 channel is found to be thermally activated (9 × 104 s-1) and less efficient when proceeding from the adiabatic S1 state. Our calculations also reveal, however, a barrierless S1→ T2 ISC pathway near the Franck-Condon region. RISC is found to essentially proceed via the T1→ S1 channel, with a rate constant of (3 × 104 s-1) if our adiabatic singlet-triplet energy gap in vacuum (ΔEST = 0.12 eV) is employed. Shifting the potentials to match two experimentally reported singlet-triplet energy gaps in toluene (ΔEST = 0.21 and 0.31 eV, respectively) leads to a drastic reduction of the computed rate constant by up to 4 orders of magnitude. The T2 state is not expected to play a major role in mediating triplet-singlet transitions in 2CzPN unless it is directly populated by hot excitons. No indication for a strong vibronic coupling of the T2 and T1 potentials is found, which could help overcome the negative exponential dependence of the RISC rate constant on the magnitude of the energy gap.
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Affiliation(s)
- Angela Rodriguez-Serrano
- Institut für Theoretische Chemie und Computerchemie, Heinrich-Heine-Universität Düsseldorf, Universitätsstraße 1, D-40225 Düsseldorf, Germany.
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Kempfer-Robertson EM, Pike TD, Thompson LM. Difference projection-after-variation double-hybrid density functional theory applied to the calculation of vertical excitation energies. J Chem Phys 2020; 153:074103. [DOI: 10.1063/5.0017222] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Affiliation(s)
| | - Thomas Dane Pike
- Department of Chemistry, University of Louisville, Louisville, Kentucky 40205, USA
| | - Lee M. Thompson
- Department of Chemistry, University of Louisville, Louisville, Kentucky 40205, USA
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Alipour M, Damiri S. Unveiling the role of short-range exact-like exchange in the optimally tuned range-separated hybrids for fluorescence lifetime modeling. J Chem Phys 2020; 152:204301. [PMID: 32486652 DOI: 10.1063/5.0007767] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
We propose and validate several variants of the optimally tuned range-separated hybrid functionals (OT-RSHs) including different density functional approximations for predicting the fluorescence lifetimes of different categories of fluorophores within the time-dependent density functional theory (TD-DFT) framework using both the polarizable continuum and state-specific solvation models. Our main idea originates from performing the optimal tuning in the presence of a contribution of the exact-like exchange at the short-range part, which, in turn, leads to the small values of the range-separation parameter, and computing the fluorescence lifetimes using the models including no or small portions of the short-range exact-like exchange. Particular attention is also paid to the influence of the geometries of emitters on fluorescence lifetime computations. It is shown that our developed OT-RSHs along with the polarizable continuum model can be considered as the promising candidates within the TD-DFT framework for the prediction of fluorescence lifetimes for various fluorophores. We find that the proposed models not only outperform their standard counterparts but also provide reliable data better than or comparable to the conventional hybrid functionals with both the fixed and interelectronic distance-dependent exact-like exchanges. Furthermore, it is also revealed that when the excited state geometries come into play, more accurate descriptions of the fluorescence lifetimes can be achieved. Hopefully, our findings can give impetus for future developments of OT-RSHs for computational modeling of other characteristics in fluorescence spectroscopy as well as for verification of the related experimental observations.
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Affiliation(s)
- Mojtaba Alipour
- Department of Chemistry, College of Sciences, Shiraz University, Shiraz 71946-84795, Iran
| | - Samaneh Damiri
- Department of Chemistry, College of Sciences, Shiraz University, Shiraz 71946-84795, Iran
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9
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How does SCAN compare to PBE in the framework of parameter-free spin-opposite-scaled double-hybrids? Chem Phys Lett 2020. [DOI: 10.1016/j.cplett.2019.136898] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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10
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Olivier Y, Sancho-Garcia JC, Muccioli L, D'Avino G, Beljonne D. Computational Design of Thermally Activated Delayed Fluorescence Materials: The Challenges Ahead. J Phys Chem Lett 2018; 9:6149-6163. [PMID: 30265539 DOI: 10.1021/acs.jpclett.8b02327] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Thermally activated delayed fluorescence (TADF) offers promise for all-organic light-emitting diodes with quantum efficiencies competing with those of transition-metal-based phosphorescent devices. While computational efforts have so far largely focused on gas-phase calculations of singlet and triplet excitation energies, the design of TADF materials requires multiple methodological developments targeting among others a quantitative description of electronic excitation energetics, fully accounting for environmental electrostatics and molecular conformational effects, the accurate assessment of the quantum mechanical interactions that trigger the elementary electronic processes involved in TADF, and a robust picture for the dynamics of these fundamental processes. In this Perspective, we describe some recent progress along those lines and highlight the main challenges ahead for modeling, which we hope will be useful to the whole TADF community.
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Affiliation(s)
- Y Olivier
- Laboratory for Chemistry of Novel Materials , University of Mons , Place du Parc 20 , B-7000 Mons , Belgium
| | - J-C Sancho-Garcia
- Departamento de Química Física , Universidad de Alicante , E-03080 Alicante , Spain
| | - L Muccioli
- Dipartimento di Chimica Industriale "Toso Montanari" , Università di Bologna , I-40136 Bologna , Italy
- Institut des Sciences Moléculaires, UMR 5255 , University of Bordeaux , F- 33405 Talence , France
| | - G D'Avino
- Institut Néel, CNRS and Grenoble Alpes University, F-38042 Grenoble , France
| | - D Beljonne
- Laboratory for Chemistry of Novel Materials , University of Mons , Place du Parc 20 , B-7000 Mons , Belgium
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11
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Al-Saadon R, Sutton C, Yang W. Accurate Treatment of Charge-Transfer Excitations and Thermally Activated Delayed Fluorescence Using the Particle-Particle Random Phase Approximation. J Chem Theory Comput 2018; 14:3196-3204. [PMID: 29772183 PMCID: PMC6192039 DOI: 10.1021/acs.jctc.8b00153] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Thermally activated delayed florescence (TADF) is a mechanism that increases the electroluminescence efficiency in organic light-emitting diodes by harnessing both singlet and triplet excitons. TADF is facilitated by a small energy difference between the first singlet (S1) and triplet (T1) excited states (Δ E(ST)), which is minimized by spatial separation of the donor and acceptor moieties. The resultant charge-transfer (CT) excited states are difficult to model using time-dependent density functional theory (TDDFT) because of the delocalization error present in standard density functional approximations to the exchange-correlation energy. In this work we explore the application of the particle-particle random phase approximation (pp-RPA) for the determination of both S1 and T1 excitation energies. We demonstrate that the accuracy of the pp-RPA is functional dependent and that, when combined with the hybrid functional B3LYP, the pp-RPA computed Δ E(ST) have a mean absolute deviation (MAD) of 0.12 eV for the set of examined molecules. A key advantage of the pp-RPA approach is that the S1 and T1 states are characterized as CT states for all of experimentally reported TADF molecules examined here, which allows for an estimate of the singlet-triplet CT excited state energy gap (Δ E(ST) = 1CT - 3CT). For experimentally known TADF molecules with a small (<0.2 eV) Δ E(ST) in this data set, a high accuracy is demonstrated for the prediction of both the S1 (MAD = 0.18 eV) and T1 (MAD = 0.20 eV) excitation energies as well as Δ E(ST) (MAD = 0.05 eV). This result is attributed to the consideration of correct antisymmetry in the particle-particle interaction leading to the use of full exchange kernel in addition to the Coulomb contribution, as well as a consistent treatment of both singlet and triplet excited states. The computational efficiency of this approach is similar to that of TDDFT, and the cost can be reduced significantly by using the active-space approach.
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Affiliation(s)
- Rachael Al-Saadon
- Department of Chemistry, Duke University, Durham, North Carolina 27708, United States
| | - Christopher Sutton
- Department of Chemistry, Duke University, Durham, North Carolina 27708, United States
| | - Weitao Yang
- Department of Chemistry, Duke University, Durham, North Carolina 27708, United States
- Key Laboratory of Theoretical Chemistry of Environment School of Chemistry and Environment, South China Normal University, Guangzhou 510631, China
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12
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On the opposite-spin to same-spin ratio of absolute and interaction MP2 correlation energy in parameter-free spin-opposite-scaled double hybrids. Chem Phys Lett 2017. [DOI: 10.1016/j.cplett.2017.07.023] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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