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Fanciullo G, Adamo C, Rivalta I, Ciofini I. Optimal-tuning of range-separated density functionals to describe the optical and photophysical properties of rhodamine B dimers. Phys Chem Chem Phys 2024; 26:23920-23933. [PMID: 39233668 DOI: 10.1039/d4cp02147a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/06/2024]
Abstract
Setting up computational approaches enabling the correct prediction of the photophysical properties of rhodamine B (RB) derivatives and their aggregates (referred to as dimers here) is of fundamental importance to rationally drive the design of novel systems of applicative relevance, such as artificial light-harvesting nanosystems. Currently, approaches rooted in time-dependent density functional theory (TD-DFT), which are appealing for their relatively low computational cost, nonetheless have limitations in terms of accuracy, especially while considering RB dimeric species. In this work, we investigated the performances of optimally tuned range-separated hybrid functionals for describing the excited states of RB and its H dimer, focusing on dimeric charge-transfer (CT) states. We compared different optimal-tuning (OT) procedures including or not solvent screening. The results show that the properties of CT states, such as their CT extent, brightness and relative energy ordering, are crucially affected by the Hartree-Fock exchange amount dictated by OT, which is in turn driven by the chosen asymptotic behavior. Finally, to understand the dissimilar pictures provided for the CT states by different tuning approaches, we performed an extensive analysis aimed at elucidating how CT states are affected by range-separation parameters. As a result, a simple procedure is finally provided for easily achieving a unique functional to be applied on both monomer and dimers, its current limitations are highlighted and possible perspectives for future development are envisaged.
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Affiliation(s)
- Giacomo Fanciullo
- Dipartimento di Chimica Industriale "Toso Montanari", Alma Mater Studiorum, Università di Bologna, Viale del Risorgimento 4, 40136 Bologna, Italy.
| | - Carlo Adamo
- Chimie ParisTech, PSL University, CNRS, Institute of Chemistry for Life and Health Sciences, Chemical Theory and Modelling Group, F-75005 Paris, France.
| | - Ivan Rivalta
- Dipartimento di Chimica Industriale "Toso Montanari", Alma Mater Studiorum, Università di Bologna, Viale del Risorgimento 4, 40136 Bologna, Italy.
- CNRS, Laboratoire de Chimie UMR 5182, 46 Allée d'Italie, 69364 Lyon, France
| | - Ilaria Ciofini
- Chimie ParisTech, PSL University, CNRS, Institute of Chemistry for Life and Health Sciences, Chemical Theory and Modelling Group, F-75005 Paris, France.
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2
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Hartstein M, Ohad G, Kronik L. Predicting the Color Polymorphism of ROY from a Time-Dependent Optimally Tuned Screened Range-Separated Hybrid Functional. J Chem Theory Comput 2024; 20:5510-5516. [PMID: 38842436 PMCID: PMC11238539 DOI: 10.1021/acs.jctc.4c00433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2024]
Abstract
Polymorphism is a well-known property of molecular crystals, which allows the same molecule to form solids with several crystalline structures that can differ significantly in physical properties. Polymorphs that possess different optical absorption properties in the visible range may exhibit different perceived colors, a phenomenon known as color polymorphism. One striking example of color polymorphism is given by 5-methyl-2-[(2-nitrophenyl)amino]-3-thiophenecarbonitrile, known as ROY for its red-orange-yellow colors. First-principles prediction of color polymorphism may help in polymorph assignment and design but has proven to be challenging. Here, we predict the absorption spectra and simulate the colors of 12 ROY polymorphs using the general, nonempirical method of time-dependent (TD) optimally tuned screened range-separated hybrid (OT-SRSH) functional. For 5 ROY polymorphs with known experimental absorption spectra, we show that the TD-OT-SRSH approach predicts absorption spectra in quantitative agreement with experiment. For all polymorphs, we show that an accurate simulation of the colors is obtained, paving the way to a fully predictive, low-cost calculation of color polymorphism.
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Affiliation(s)
- Michal Hartstein
- Department of Molecular Chemistry and Materials Science, Weizmann Institute of Science, Rehovoth 7610001, Israel
| | - Guy Ohad
- Department of Molecular Chemistry and Materials Science, Weizmann Institute of Science, Rehovoth 7610001, Israel
| | - Leeor Kronik
- Department of Molecular Chemistry and Materials Science, Weizmann Institute of Science, Rehovoth 7610001, Israel
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3
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Vinod K, Jadhav SD, Hariharan M. Room Temperature Phosphorescence in Crystalline Iodinated Eumelanin Monomer. Chemistry 2024; 30:e202400499. [PMID: 38502668 DOI: 10.1002/chem.202400499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2024] [Revised: 03/01/2024] [Accepted: 03/19/2024] [Indexed: 03/21/2024]
Abstract
We report the room temperature phosphorescence upon iodination on a crystalline eumelanin monomer with shielded hydroxyl moieties, ethyl 5,6-dimethoxyindole-2-carboxylate (DMICE). Ultrafast intersystem crossing (ISC) is observed in the iodinated (IDMICE) as well as brominated (BDMICE) analogues of the eumelanin monomer derivative in solution. The triplet quantum yields (φT) and intersystem crossing rates (kISC) of the halogenated eumelanin derivatives areφ T B D M I C E ${{\phi{} }_{T}^{BDMICE}}$ =25.4±1.1 %;k I S C B D M I C E ${{k}_{ISC}^{BDMICE}}$ =1.95×109 s-1 andφ T I D M I C E ${{\phi{} }_{T}^{IDMICE}}$ =59.1±1.6 %;k I S C I D M I C E = ${{k}_{ISC}^{IDMICE}=}$ 1.36×1010 s-1, as monitored using transient absorption spectroscopy. Theoretical calculations based on nuclear ensemble method reveal that computed kISC and spin-orbit coupling matrix elements for eumelanin derivatives are larger for IDMICE relative to BDMICE. The halogen and π-π interactions, with distinct excitonic coupling and higher ISC rate promote phosphorescence in IDMICE molecular crystals. Accessing triplet excited states and resultant photoluminescence through structural modification of eumelanin scaffolds paves way for exploring the versatility of eumelanin-inspired molecules as bio-functional materials.
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Affiliation(s)
- Kavya Vinod
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram (IISER TVM), Maruthamala P.O., Vithura, Thiruvananthapuram, 695551, Kerala, India
| | - Sohan D Jadhav
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram (IISER TVM), Maruthamala P.O., Vithura, Thiruvananthapuram, 695551, Kerala, India
| | - Mahesh Hariharan
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram (IISER TVM), Maruthamala P.O., Vithura, Thiruvananthapuram, 695551, Kerala, India
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4
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Begam K, Aksu H, Dunietz BD. Antioxidative Triplet Excitation Energy Transfer in Bacterial Reaction Center Using a Screened Range Separated Hybrid Functional. J Phys Chem B 2024. [PMID: 38687467 DOI: 10.1021/acs.jpcb.3c08501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2024]
Abstract
Excess energy absorbed by photosystems (PSs) can result in photoinduced oxidative damage. Transfer of such energy within the core pigments of the reaction center in the form of triplet excitation is important in regulating and preserving the functionality of PSs. In the bacterial reaction center (BRC), the special pair (P) is understood to act as the electron donor in a photoinduced charge transfer process, triggering the charge separation process through the photoactive branch A pigments that experience a higher polarizing environment. At this work, triplet excitation energy transfer (TEET) in BRC is studied using a computational perspective to gain insights into the roles of the dielectric environment and interpigment orientations. We find in agreement with experimental observations that TEET proceeds through branch B. The TEET process toward branch B pigment is found to be significantly faster than the hypothetical process proceeding through branch A pigments with ps and ms time scales, respectively. Our calculations find that conformational differences play a major role in this branch asymmetry in TEET, where the dielectric environment asymmetry plays only a secondary role in directing the TEET to proceed through branch B. We also address TEET processes asserting the role of carotenoid as the final triplet energy acceptor and in a mutant form, where the branch pigments adjacent to P are replaced by bacteriopheophytins. The necessary electronic excitation energies and electronic state couplings are calculated by the recently developed polarization-consistent framework combining a screened range-separated hybrid functional and a polarizable continuum mode. The polarization-consistent potential energy surfaces are used to parametrize the quantum mechanical approach, implementing Fermi's golden rule expression of the TEET rate calculations.
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Affiliation(s)
- Khadiza Begam
- Department of Physics, Kent State University, Kent, Ohio 44242, United States
| | - Huseyin Aksu
- Department of Physics, Faculty of Science at Canakkale Onsekiz Mart University, Canakkale 17100, Turkey
| | - Barry D Dunietz
- Department of Chemistry and Biochemistry, Kent State University, Kent, Ohio 44242, United States
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5
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Soltani Nejad M, Alipour M. How does theory compare to experiment for oscillator strengths in electronic spectra? Proposing range-separated hybrids with reliable accountability. Phys Chem Chem Phys 2024; 26:879-894. [PMID: 38087910 DOI: 10.1039/d3cp04793h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2024]
Abstract
As an important quantity in atomic and molecular spectroscopy, oscillator strength should be mentioned. Oscillator strength is linked to the transition dipole moment and consequently to the transition probability between two states, where its magnitude is directly connected to the intensity of the peaks in ultraviolet-visible spectra. However, accurately accounting for oscillator strengths still remains one of the greatest challenges in theory and experiment. Given previous efforts in the context of investigations into oscillator strengths, the related theoretical treatments are relatively limited and have proven to be challenging. In this work, the oscillator strengths in the electronic spectra of organic compounds have thoroughly been investigated with the help of optimally tuned range-separated hybrids (OT-RSHs). In particular, variants of the OT-RSHs combined with the polarizable continuum model (PCM), OT-RSHs-PCM, as well as their screened versions accounting for the screening effects by the electron correlation through the dielectric constant, OT-SRSHs-PCM, are proposed for reliable prediction of the oscillator strengths. The role of the involved ingredients in the proposed methods, namely the underlying density functional approximations, short-range and long-range Hartree-Fock (HF) exchange, as well as the range-separation parameter, has been examined in detail. It is shown that any combination of the parameters in the proposed approximations does not render the reliable oscillator strengths, but a particular compromise among them is needed to describe the experimental data well. Perusing all the results of our developed methods, the best ones are found to be the generalized gradient approximation-based OT-RSHs-PCM, coupled with the linear response theory in the non-equilibrium solvation regime, with the correct asymptotic behavior and incorporating no (low) HF exchange contributions in the short-range part. The best proposed approximations also reveal superior performances not only with respect to their standard counterparts with the default parameters but also as compared to earlier range-separated functionals. Finally, the applicability of the best approximation is also put into broader perspective, where it is used for predicting the oscillator strengths in other sets of compounds not included in the process of developing the approximations. Hopefully, our proposed method can function as an affordable alternative to the expensive wave function-based methods for both theoretical modeling and confirming the experimental observations in the field of electronic spectroscopy.
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Affiliation(s)
- Mahdi Soltani Nejad
- Department of Chemistry, School of Science, Shiraz University, Shiraz 71946-84795, Iran.
| | - Mojtaba Alipour
- Department of Chemistry, School of Science, Shiraz University, Shiraz 71946-84795, Iran.
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6
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Schubert A, Bhandari S, Geva E, Dunietz BD. A Computational Study of the Electronic Energy and Charge Transfer Rates and Pathways in the Tetraphenyldibenzoperiflanthene/Fullerene Interfacial Dyad. J Phys Chem Lett 2023; 14:9569-9583. [PMID: 37862043 DOI: 10.1021/acs.jpclett.3c01927] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2023]
Abstract
The electronic transition rates and pathways underlying interfacial charge separation in tetraphenyldibenzoperiflanthene:fullerene (DBP:C70) blends are investigated computationally. The analysis is based on a polarization-consistent framework employing screened range-separated hybrid functional in a polarizable continuum model to parametrize Fermi's golden rule rate theory. The model considers the possible transitions within the 25 lowest excited states of a DBP:C70 dyad that are accessible by photoexcitation. The different identified pathways contributing to charge carrier generation include electron and hole transfer and backtransfer, exciton transfer, and internal relaxation steps. The larger density of states of C70 appears to explain the previously observed larger efficiency for charge separation through hole transfer mechanism. We also analyze the validity of the high-temperature and short-time semiclassical approximations of the FGR theory, where both overestimated and underestimated Marcus theory based constants can be affected.
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Affiliation(s)
- Alexander Schubert
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
- Department of Chemistry and Biochemistry, Kent State University, Kent, Ohio 44242, United States
| | - Srijana Bhandari
- Department of Chemistry and Biochemistry, Kent State University, Kent, Ohio 44242, United States
| | - Eitan Geva
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Barry D Dunietz
- Department of Chemistry and Biochemistry, Kent State University, Kent, Ohio 44242, United States
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7
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Hojo R, Bergmann K, Elgadi SA, Mayder DM, Emmanuel MA, Oderinde MS, Hudson ZM. Imidazophenothiazine-Based Thermally Activated Delayed Fluorescence Materials with Ultra-Long-Lived Excited States for Energy Transfer Photocatalysis. J Am Chem Soc 2023; 145:18366-18381. [PMID: 37556344 DOI: 10.1021/jacs.3c04132] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/11/2023]
Abstract
Triplet-triplet energy transfer (EnT) is a powerful activation pathway in photocatalysis that unlocks new organic transformations and improves the sustainability of organic synthesis. Many current examples, however, still rely on platinum-group metal complexes as photosensitizers, with associated high costs and environmental impacts. Photosensitizers that exhibit thermally activated delayed fluorescence (TADF) are attractive fully organic alternatives in EnT photocatalysis. However, TADF photocatalysts incorporating heavy atoms remain rare, despite their utility in inducing efficient spin-orbit-coupling, intersystem-crossing, and consequently a high triplet population. Here, we describe the synthesis of imidazo-phenothiazine (IPTZ), a sulfur-containing heterocycle with a locked planar structure and a shallow LUMO level. This acceptor is used to prepare seven TADF-active photocatalysts with triplet energies up to 63.9 kcal mol-1. We show that sulfur incorporation improves spin-orbit coupling and increases triplet lifetimes up to 3.64 ms, while also allowing for tuning of photophysical properties via oxidation at the sulfur atom. These IPTZ materials are applied as photocatalysts in five seminal EnT reactions: [2 + 2] cycloaddition, the disulfide-ene reaction, and Ni-mediated C-O and C-N cross-coupling to afford etherification, esterification, and amination products, outcompeting the industry-standard TADF photocatalyst 2CzPN in four of the five studied scenarios. Detailed photophysical and theoretical studies are used to understand structure-activity relationships and to demonstrate the key role of the heavy atom effect in the design of TADF materials with superior photocatalytic performance.
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Affiliation(s)
- Ryoga Hojo
- Department of Chemistry, The University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Katrina Bergmann
- Department of Chemistry, The University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Seja A Elgadi
- Department of Chemistry, The University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Don M Mayder
- Department of Chemistry, The University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Megan A Emmanuel
- Chemical Process Development, Bristol Myers Squibb Company, New Brunswick, New Jersey 08903, United States
| | - Martins S Oderinde
- Department of Discovery Synthesis, Bristol Myers Squibb Research and Early Development, 3551 Lawrenceville Road, Princeton, New Jersey 08540, United States
| | - Zachary M Hudson
- Department of Chemistry, The University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
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8
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Bradbury NC, Allen T, Nguyen M, Ibrahim KZ, Neuhauser D. Optimized attenuated interaction: Enabling stochastic Bethe-Salpeter spectra for large systems. J Chem Phys 2023; 158:2882253. [PMID: 37094001 DOI: 10.1063/5.0146555] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 04/03/2023] [Indexed: 04/26/2023] Open
Abstract
We develop an improved stochastic formalism for the Bethe-Salpeter equation (BSE), based on an exact separation of the effective-interaction W into two parts, W = (W - vW) + vW, where the latter is formally any translationally invariant interaction, vW(r - r'). When optimizing the fit of the exchange kernel vW to W, using a stochastic sampling W, the difference W - vW becomes quite small. Then, in the main BSE routine, this small difference is stochastically sampled. The number of stochastic samples needed for an accurate spectrum is then largely independent of system size. While the method is formally cubic in scaling, the scaling prefactor is small due to the constant number of stochastic orbitals needed for sampling W.
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Affiliation(s)
- Nadine C Bradbury
- Department of Chemistry and Biochemistry, UCLA, Los Angeles, California 90095-1569, USA
| | - Tucker Allen
- Department of Chemistry and Biochemistry, UCLA, Los Angeles, California 90095-1569, USA
| | - Minh Nguyen
- Department of Chemistry and Biochemistry, UCLA, Los Angeles, California 90095-1569, USA
| | - Khaled Z Ibrahim
- Computer Science Department, Lawrence Berkeley National Laboratory, One Cyclotron Road, Berkeley, California 94720, USA
| | - Daniel Neuhauser
- Department of Chemistry and Biochemistry, and California Nanoscience Institute, UCLA, Los Angeles, California 90095-1569, USA
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9
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Bergmann K, Hojo R, Hudson ZM. Uncovering the Mechanism of Thermally Activated Delayed Fluorescence in Coplanar Emitters Using Potential Energy Surface Analysis. J Phys Chem Lett 2023; 14:310-317. [PMID: 36602966 DOI: 10.1021/acs.jpclett.2c03425] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Planarized emitters exhibiting thermally activated delayed fluorescence (TADF) have attracted attention due to their narrow emission spectra, improved photostability, and high quantum yields, but with large singlet-triplet energy gaps (ΔEST) and no heavy atoms, the origin of their TADF remains a subject of debate. Here we prepare two isomeric, coplanar donor-acceptor compounds, with HMAT-2PYM performing dual TADF and room-temperature phosphorescence but with HMAT-4PYM exhibiting only prompt fluorescence. Although conventional TADF design principles suggest that neither isomer should exhibit TADF, we reveal differences in the excited state potential energy surfaces that enable spin-flip processes in only one isomer. We also find that hydrogen bonding is absent between the planar units of these emitters, despite earlier claims of intramolecular hydrogen bonding in similar compounds. Overall, this work demonstrates that potential energy surface analysis is a practical strategy for designing coplanar TADF materials that might otherwise be overlooked by conventional TADF design metrics.
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Affiliation(s)
- Katrina Bergmann
- Department of Chemistry, The University of British Columbia, 2036 Main Mall, Vancouver, British Columbia, Canada V6T 1Z1
| | - Ryoga Hojo
- Department of Chemistry, The University of British Columbia, 2036 Main Mall, Vancouver, British Columbia, Canada V6T 1Z1
| | - Zachary M Hudson
- Department of Chemistry, The University of British Columbia, 2036 Main Mall, Vancouver, British Columbia, Canada V6T 1Z1
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10
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Mandal B, Dunietz BD. Effects of Solvent Dielectric on Thermally Activated Delayed Fluorescence: A Predictive Computational Polarization Consistent Approach. J Phys Chem A 2023; 127:216-223. [PMID: 36563166 DOI: 10.1021/acs.jpca.2c08154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
We study computationally thermally activated delayed fluorescence (TADF) in donor-acceptor compounds. The relevant electronic excited states that are strongly affected by the dielectric environment are treated by a polarization consistent framework. The high fidelity potential energy surfaces are used following a quantum-mechanical Fermi's golden rule (FGR) picture to calculate rates of intersystem crossing (ISC) and reverse intersystem crossing (RISC). To demonstrate the potency of the approach, we consider isomers of benzonitrile functionalized tert-butyl-substituted dimethylacridine (DMAC-BN), which were recently found to perform well as TADF emitters. The calculated excited state energies that appear to reproduce well measured spectral trends with respect to the dielectric constant are used to parametrize ISC/RISC FGR rates. The calculated rates reproduce well measured rates, whereas semiclassical based rates are grossly underestimated. In particular, we find in agreement with the recent experimental study [Phys. Rev. Appl.2019, 12, 044021] that the ortho and meta isomers are significantly more effective as TADF emitters. The computational framework provides valuable insight at the molecular level into RISC rates and therefore can contribute to the design of materials of increased TADF efficiency.
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Affiliation(s)
- Bikash Mandal
- Department of Chemistry and Biochemistry, Kent State University, Kent, Ohio44242-0001, United States
| | - Barry D Dunietz
- Department of Chemistry and Biochemistry, Kent State University, Kent, Ohio44242-0001, United States
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11
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Evariste S, Harrison AM, Sarkar S, Rheingold AL, Dunietz BD, Heinicke JW, Delgado Rosario E, Yoon S, Teets TS, Protasiewicz JD. Luminescent 1 H-1,3-benzazaphospholes. RSC Adv 2022; 13:594-601. [PMID: 36605673 PMCID: PMC9773327 DOI: 10.1039/d2ra07226b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Accepted: 12/14/2022] [Indexed: 12/24/2022] Open
Abstract
2-R-1H-1,3-Benzazaphospholes (R-BAPs) are an interesting class of σ2P heterocycles containing P[double bond, length as m-dash]C bonds. While closely related 2-R-1,3-benzoxaphospholes (R-BOPs) have been shown to be highly photoluminescent materials depending on specific R substituents, photoluminescence of R-BAPs has been previously limited to an example having a fused carbazole ring system. Here we detail the synthesis and structural characterization of a new R-BAP (3c, R = 2,2'-dithiophene), and compare its photoluminescence against two previously reported R-BAPs (3a, R, R' = Me and 3b, R = 2-thiophene). The significant fluorescence displayed by the thiophene derivatives 3b (φ = 0.53) and 3c (φ = 0.12) stands in contrast to the weakly emissive methyl substituted analogue 3a (φ = 0.08). Comparative computational investigations of 3a-c offer insights into the interplay between structure-function relationships affecting excited state relaxation processes.
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Affiliation(s)
- Sloane Evariste
- Department of Chemistry, Case Western Reserve UniversityClevelandOhio 44106USA
| | | | - Sunandan Sarkar
- Department of Chemistry, National Institute of Technology TiruchirappalliTiruchirappalliTamil Nadu 620015India
| | - Arnold L. Rheingold
- Department of Chemistry and Biochemistry, University of CaliforniaLa JollaSan DiegoCalifornia 92093USA
| | - Barry D. Dunietz
- Department of Chemistry and Biochemistry, Kent State UniversityKentOhio 44242USA
| | - Joachim W. Heinicke
- Institut für Biochemie, Anorganische Chemie, Ernst-Moritz-Arndt-Universität GreifswaldFelix-Hausdorff-Str. 4, D-17489GreisfwaldGermany
| | | | - Sungwoon Yoon
- Department of Chemistry, University of Houston3585 Cullen Blvd. Room 112HoustonTX 77204-5003USA
| | - Thomas S. Teets
- Department of Chemistry, University of Houston3585 Cullen Blvd. Room 112HoustonTX 77204-5003USA
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12
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Barretta P, Ponte F, Scoditti S, Vigna V, Mazzone G, Sicilia E. Computational Analysis of the Behavior of BODIPY Decorated Monofunctional Platinum(II) Complexes in the Dark and under Light Irradiation. J Phys Chem A 2022; 126:7159-7167. [PMID: 36194386 PMCID: PMC9574924 DOI: 10.1021/acs.jpca.2c04544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Dual-action drugs are occupying an important place in the scientific landscape of cancer research owing to the possibility to combine different therapeutic strategies into a single molecule. In the present work, the behavior of two BODIPY-appended monofunctional Pt(II) complexes, one mononuclear and one binuclear, recently synthesized and tested for their cytotoxicity have been explored both in the dark and under light irradiation. Quantum mechanical DFT calculations have been used to carry out the exploration of the key steps, aquation and guanine attack, of the mechanism of action of Pt(II) complexes in the dark. Due to the presence of the BODIPY chromophore and the potential capability of the two investigated complexes to work as photosensitizers in PDT, time dependent DFT has been employed to calculate their photophysical properties and to inspect how the sensitizing properties of BODIPY are affected by the presence of the platinum "heavy atom". Furthermore, also the eventual influence on of the photophysical properties due to the displacement of chlorido ligands by water and of water by guanine has been taken into consideration.
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Affiliation(s)
- Pierraffaele Barretta
- Department of Chemistry and Chemical Technologies, University of Calabria, Ponte P. Bucci, 87036 Arcavacata di Rende (CS), Italy
| | - Fortuna Ponte
- Department of Chemistry and Chemical Technologies, University of Calabria, Ponte P. Bucci, 87036 Arcavacata di Rende (CS), Italy
| | - Stefano Scoditti
- Department of Chemistry and Chemical Technologies, University of Calabria, Ponte P. Bucci, 87036 Arcavacata di Rende (CS), Italy
| | - Vincenzo Vigna
- Department of Chemistry and Chemical Technologies, University of Calabria, Ponte P. Bucci, 87036 Arcavacata di Rende (CS), Italy
| | - Gloria Mazzone
- Department of Chemistry and Chemical Technologies, University of Calabria, Ponte P. Bucci, 87036 Arcavacata di Rende (CS), Italy
| | - Emilia Sicilia
- Department of Chemistry and Chemical Technologies, University of Calabria, Ponte P. Bucci, 87036 Arcavacata di Rende (CS), Italy
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13
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Alipour M, Izadkhast T. Toward highly efficient hyperfluorescence-based emitters through excited-states alignment using novel optimally tuned range-separated models. Phys Chem Chem Phys 2022; 24:23718-23736. [PMID: 36155689 DOI: 10.1039/d2cp03395j] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Hyperfluorescence has recently been introduced as a promising strategy to achieve organic light-emitting diodes (OLEDs) with high color purity and enhanced stability. In this approach, fluorescent emitters (FEs) with strong and narrow band fluorescence are integrated in thin films containing sensitizers exhibiting thermally activated delayed fluorescence (TADF). Toward highly efficient hyperfluorescence-based emitters, the excited-states ordering of the FEs should be well-aligned. Given some recent endeavors in this context, the related theoretical explorations are relatively limited and have proven to be challenging. In this work, alignments of the corresponding excited-states, crucial for both the fast Förster resonance energy transfer and suppression of the Dexter energy transfer from TADF sensitizers to FEs, have theoretically been investigated using optimally tuned range-separated hybrid functionals (OT-RSHs). We have proposed and validated several variants of the models including OT-RSHs, their coupled versions with the polarizable continuum model, OT-RSHs-PCM, as well as the screened versions accounting for the screening effects by the electron correlation through the scalar dielectric constant, OT-SRSHs, for a reliable description of the excited-states ordering in the FEs of the hyperfluorescence-based materials. Particular attention is paid to the influence of the underlying density functional approximations as well as the short- and long-range Hartree-Fock (HF) exchange contributions and the range-separation parameter. Considering a series of experimentally known hyperfluorescence-based emitters as working models, it is unveiled that any combination of the ingredients in the proposed models does not render the correct order of the excited-states of the FEs, but a particular compromise among the involved parameters is needed to more accurately account for the relevant excited-states alignment. Perusing the results of our developed methods, the best ones are found to be the generalized gradient approximation-based OT-RSHs-PCM with the correct asymptotic behavior and incorporating no (low) HF exchange contribution at the short-range regime. The proposed models show superior performances not only with respect to their standard counterparts with the default parameters but also as compared to other range-separated approximations. Accountability of the best-proposed model is also put into broader perspective, where it has been employed for the computational design of several molecules as promising FE candidates prone to be utilized in hyperfluorescence-based materials. Summing up, the proposed models in this study can be recommended for both the theoretical modeling and confirming the experimental observations in the field of hyperfluorescence-based OLEDs.
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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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14
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Begam K, Cohen L, Goobes G, Dunietz BD. Solvent Dependent Nuclear Magnetic Resonance Molecular Parameters Based on a Polarization Consistent Screened Range Separated Hybrid Density Functional Theory Framework. J Chem Theory Comput 2022; 18:5259-5266. [PMID: 35929782 DOI: 10.1021/acs.jctc.2c00275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Nuclear magnetic resonance (NMR) properties of solvated molecules are significantly affected by the solvent. We, therefore, employ a polarization consistent framework that efficiently addresses the solvent polarizing environment effects. Toward this goal a dielectric screened range separated hybrid (SRSH) functional is invoked with a polarizable continuum model (PCM) to properly represent the orbital gap in the condensed phase. We build on the success of range separated hybrid (RSH) functionals to address the erroneous tendency of traditional density functional theory (DFT) to collapse the orbital gap. Recently, the impact of RSH that properly opens up the orbital gap in gas-phase calculations on NMR properties has been assessed. Here, we report the use of SRSH-PCM that produces properly solute orbital gaps in calculating isotropic nuclear magnetic shielding and chemical shift parameters of molecular systems in the condensed phase. We show that in contrast to simpler DFT-PCM approaches, SRSH-PCM successfully follows expected dielectric constant trends.
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Affiliation(s)
- Khadiza Begam
- Department of Physics, Kent State University, Kent, Ohio 44242, United States
| | - Lilian Cohen
- Department of Chemistry and Institute for Nanotechnology and Advanced Materials Bar Ilan University, Ramat Gan 5290002, Israel
| | - Gil Goobes
- Department of Chemistry and Institute for Nanotechnology and Advanced Materials Bar Ilan University, Ramat Gan 5290002, Israel
| | - Barry D Dunietz
- Department of Chemistry and Biochemistry, Kent State University, Kent, Ohio 44242, United States
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15
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Kretz B, Egger D. Accurate Non-Adiabatic Couplings from Optimally-Tuned Range-Separated Hybrid Functionals. J Chem Phys 2022; 157:101104. [DOI: 10.1063/5.0099854] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Precise theoretical calculations of non-adiabatic couplings, which describe the interaction between two Born-Oppenheimer surfaces, are important for the modeling of radiationless decay mechanisms in photochemical processes. Here, we demonstrate that accurate non-adiabatic couplings can be calculated in the framework of linear-response time-dependent density functional theory by using non-empirical, optimally-tuned range-separated hybrid (OT-RSH) functionals. We focus on molecular radicals, in which ultrafast non-radiative decay plays a crucial role, to find that the OT-RSH functional compares well to wave-function based reference data and competes with the accuracy of semi-empirical CAM-B3LYP calculations. Our findings show that the OT-RSH approach provides very accurate non-adiabatic couplings and, therefore, provides a computationally efficient alternative to wave-function based techniques.
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16
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Chakravarty C, Aksu H, Martinez B JA, Ramos P, Pavanello M, Dunietz BD. Role of Dielectric Screening in Calculating Excited States of Solvated Azobenzene: A Benchmark Study Comparing Quantum Embedding and Polarizable Continuum Model for Representing the Solvent. J Phys Chem Lett 2022; 13:4849-4855. [PMID: 35617015 DOI: 10.1021/acs.jpclett.2c00982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The low energy excited states of the conformational isomers of solvated azobenzene are calculated with several DFT methods accounting for the solute-solvent interaction implicitly with the polarizable continuum model or explicitly with subsystem DFT. For the latter, embedding potentials are calculated for 21 sampled snapshots of the solvent molecules. First, we find that accounting for the solvent implicitly or explicitly has little effect on the predicted cis-trans S1 excitation energy gap. Second, we find that azobenzene's S1 cis and trans energies are accurate as long as a screened range-separated hybrid exchange-correlation functional is employed. Finally, we also tested a simplified workflow whereby a single, averaged, embedding potential is used. Unfortunately, we find larger deviations against the experiment for the simplified workflow. This highlights a basic flaw in the approach, where the time scale of solvent averaging is much longer than that of the solute's electronic polarization.
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Affiliation(s)
- Chandrima Chakravarty
- Department of Chemistry and Biochemistry, Kent State University, Kent, Ohio 44242, United States
| | - Huseyin Aksu
- Department of Chemistry and Biochemistry, Kent State University, Kent, Ohio 44242, United States
- Computational Physics Laboratory, Department of Physics, Pamukkale University, 20010 Denizli, Turkey
| | - Jessica A Martinez B
- Department of Chemistry, Rutgers University, Newark, New Jersey 07102, United States
| | - Pablo Ramos
- Department of Chemistry, Rutgers University, Newark, New Jersey 07102, United States
| | - Michele Pavanello
- Department of Chemistry, Rutgers University, Newark, New Jersey 07102, United States
| | - Barry D Dunietz
- Department of Chemistry and Biochemistry, Kent State University, Kent, Ohio 44242, United States
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17
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Alipour M, Damiri S. Excited-state properties of organic semiconductor dyes as electrically pumped lasing candidates from new optimally tuned range-separated models. Phys Chem Chem Phys 2022; 24:8003-8014. [PMID: 35315460 DOI: 10.1039/d1cp05363a] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Even though many efforts have been devoted to optical lasing in recent years, the realization of lasing by direct electrical excitation of organic semiconductors is hampered mainly due to optical losses from electrical contacts and electrical losses induced by triplets and polarons at high current densities. Hereby, accurately accounting for the electrically pumped organic semiconductor laser diodes (OSLDs) still remains one of the greatest challenges in optoelectronics. In this work, the excited-state characteristics of the organic semiconductor dyes used in the electrically pumped OSLDs have thoroughly been investigated using optimally tuned range-separated hybrids (OT-RSHs). Considering several experimentally known compounds of the electrically pumped OSLDs as working models, several variants of OT-RSHs, their combination forms with the polarizable continuum model (PCM), OT-RSH-PCM, as well as their screened versions accounting for the screening effects by the electron correlation through the scalar dielectric constant, OT-SRSHs, have been proposed for reliable prediction of their emission energies and oscillator strengths in both the gas and solvent phases. The role of involved ingredients in the models, namely, the underlying density functional approximations, short- and long-range exact-like exchange, as well as the range-separation parameter, has been examined in detail. It is shown that the newly designed OT-RSHs with the correct behavior of asymptotic exchange-correlation potential outperform the standard RSHs and other density functionals with both fixed and interelectronic distance-dependent exact-like exchange for describing the excite-state properties of compounds of the electrically pumped OSLDs. Concerning the computational cost of the models, it is unveiled that performing both the optimal tuning procedure and subsequent excited-state computations using OT-RSHs in the gas phase can be considered as a more reliable and affordable framework. Finally, the applicability of the proposed models is also put into a broader perspective for the computational design of several compounds as promising candidates to be used in the OSLD materials. Hopefully, our recommended OT-RSHs can function as efficient models for both the related theoretical modeling and confirming the experimental observations in the field of electrically pumped OSLDs.
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Affiliation(s)
- Mojtaba Alipour
- Department of Chemistry, School of Science, Shiraz University, Shiraz 71946-84795, Iran.
| | - Samaneh Damiri
- Department of Chemistry, School of Science, Shiraz University, Shiraz 71946-84795, Iran.
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18
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Enhancing fluorescence and lowering the optical gap through C P doping of a π-conjugated molecular backbone: A computational-based design approach. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY 2021. [DOI: 10.1016/j.jpap.2021.100089] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
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19
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Chakravarty C, Aksu H, Maiti B, Dunietz BD. Electronic Spectra of C 60 Films Using Screened Range Separated Hybrid Functionals. J Phys Chem A 2021; 125:7625-7632. [PMID: 34448570 DOI: 10.1021/acs.jpca.1c04908] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We study computationally the electronic spectra of C60 thin films using the recently developed density functional theory (DFT) framework combining a screened range separated hybrid (SRSH) functional with a polarizable continuum model (PCM). The SRSH-PCM approach achieves excellent correspondence between the frontier orbital's energy levels and the ionization potential and electron affinity of the molecular system at the condensed phase and consequently leads to high quality electronic excitation energies when used in time-dependent DFT calculations. Our calculated excited states reproduce the experimentally main reported spectral peaks at the 3.6-4.6 eV energy range and when addressing excitonic effects also reproduce the red-shifted spectral feature. Notably, we analyze the low-lying peak at 2.7 eV and associate it to an excitonic state.
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Affiliation(s)
- Chandrima Chakravarty
- Department of Chemistry and Biochemistry, Kent State University, Kent, Ohio 44242-0001, United States
| | - Huseyin Aksu
- Department of Chemistry and Biochemistry, Kent State University, Kent, Ohio 44242-0001, United States
| | - Buddhadev Maiti
- Department of Chemistry and Biochemistry, Kent State University, Kent, Ohio 44242-0001, United States
| | - Barry D Dunietz
- Department of Chemistry and Biochemistry, Kent State University, Kent, Ohio 44242-0001, United States
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20
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Tinnin J, Aksu H, Tong Z, Zhang P, Geva E, Dunietz BD, Sun X, Cheung MS. CTRAMER: An open-source software package for correlating interfacial charge transfer rate constants with donor/acceptor geometries in organic photovoltaic materials. J Chem Phys 2021; 154:214108. [PMID: 34240998 DOI: 10.1063/5.0050574] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
In this paper, we present CTRAMER (Charge-Transfer RAtes from Molecular dynamics, Electronic structure, and Rate theory)-an open-source software package for calculating interfacial charge-transfer (CT) rate constants in organic photovoltaic (OPV) materials based on ab initio calculations and molecular dynamics simulations. The software is based on identifying representative donor/acceptor geometries within interfacial structures obtained from molecular dynamics simulation of donor/acceptor blends and calculating the corresponding Fermi's golden rule CT rate constants within the framework of the linearized-semiclassical approximation. While the methods used are well established, the integration of these state-of-the-art tools originating from different disciplines to study photoinduced CT processes with explicit treatment of the environment, in our opinion, makes this package unique and innovative. The software also provides tools for investigating other observables of interest. After outlining the features and implementation details, the usage and performance of the software are demonstrated with results from an example OPV system.
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Affiliation(s)
- Jacob Tinnin
- Department of Physics, University of Houston, 617 Science and Research Building 1, Houston, Texas 77204, USA
| | - Huseyin Aksu
- Department of Chemistry and Biochemistry, Kent State University, 1175 Risman Drive, Kent, Ohio 44242, USA
| | - Zhengqing Tong
- Division of Arts and Sciences, NYU Shanghai, 1555 Century Avenue, Shanghai 200122, China; NYU-ECNU Center for Computational Chemistry at NYU Shanghai, 3663 Zhongshan Road North, Shanghai 200062, China; and Department of Chemistry, New York University, New York, New York 10003, USA
| | - Pengzhi Zhang
- Department of Physics, University of Houston, 617 Science and Research Building 1, Houston, Texas 77204, USA
| | - Eitan Geva
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, USA
| | - Barry D Dunietz
- Department of Chemistry and Biochemistry, Kent State University, 1175 Risman Drive, Kent, Ohio 44242, USA
| | - Xiang Sun
- Division of Arts and Sciences, NYU Shanghai, 1555 Century Avenue, Shanghai 200122, China; NYU-ECNU Center for Computational Chemistry at NYU Shanghai, 3663 Zhongshan Road North, Shanghai 200062, China; and Department of Chemistry, New York University, New York, New York 10003, USA
| | - Margaret S Cheung
- Department of Physics, University of Houston, 617 Science and Research Building 1, Houston, Texas 77204, USA
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21
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Aksu H, Maiti B, Ptaszek M, Dunietz BD. Photoinduced charge transfer in Zn(II) and Au(III)-ligated symmetric and asymmetric bacteriochlorin dyads: A computational study. J Chem Phys 2021; 153:134111. [PMID: 33032416 DOI: 10.1063/5.0023609] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The excited-state properties and photoinduced charge-transfer (CT) kinetics in a series of symmetrical and asymmetrical Zn- and Au-ligated meso-meso-connected bacteriochlorin (BChl) complexes are studied computationally. BChl derivatives, which are excellent near-IR absorbing chromophores, are found to play a central role in bacterial photosynthetic reaction centers but are rarely used in artificial solar energy harvesting systems. The optical properties of chemically linked BChl complexes can be tuned by varying the linking group and involving different ligated metal ions. We investigate charge transfer in BChl dyads that are either directly linked or through a phenylene ring (1,4-phenylene) and which are ligating Zn or Au ions. The directly linked dyads with a nearly perpendicular arrangement of the BChl units bear markedly different properties than phenylene linked dyads. In addition, we find that the dielectric dependence of the intramolecular CT rate is very strong in neutral Zn-ligated dyads, whereas cationic Au-ligated dyads show negligible dielectric dependence of the CT rate. Rate constants of the photo induced CT process are calculated at the semiclassical Marcus level and are compared to fully quantum mechanical Fermi's golden rule based values. The rates are calculated using a screened range separated hybrid functional that offers a consistent framework for addressing environment polarization. We study solvated systems in two solvents of a low and a high scalar dielectric constant.
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Affiliation(s)
- Huseyin Aksu
- Department of Chemistry and Biochemistry, Kent State University, Kent, Ohio 44242-0001, USA
| | - Buddhadev Maiti
- Department of Chemistry and Biochemistry, Kent State University, Kent, Ohio 44242-0001, USA
| | - Marcin Ptaszek
- Department of Chemistry and Biochemistry, University of Maryland, Baltimore, Maryland 21250-1000, USA
| | - Barry D Dunietz
- Department of Chemistry and Biochemistry, Kent State University, Kent, Ohio 44242-0001, USA
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22
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A comparative study of PffBT4T-2OD/EH-IDTBR and PffBT4T-2OD/PC71BM organic photovoltaic heterojunctions. J Photochem Photobiol A Chem 2021. [DOI: 10.1016/j.jphotochem.2021.113225] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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23
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Kraisler E, Hodgson MJP, Gross EKU. From Kohn-Sham to Many-Electron Energies via Step Structures in the Exchange-Correlation Potential. J Chem Theory Comput 2021; 17:1390-1407. [PMID: 33595312 PMCID: PMC8363072 DOI: 10.1021/acs.jctc.0c01093] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
![]()
Accurately
describing excited states within Kohn–Sham (KS)
density functional theory (DFT), particularly those which induce ionization
and charge transfer, remains a great challenge. Common exchange-correlation
(xc) approximations are unreliable for excited states owing, in part,
to the absence of a derivative discontinuity in the xc energy (Δ),
which relates a many-electron energy difference to the corresponding
KS energy difference. We demonstrate, analytically and numerically,
how the relationship between KS and many-electron energies leads to
the step structures observed in the exact xc potential in four scenarios:
electron addition, molecular dissociation, excitation of a finite
system, and charge transfer. We further show that steps in the potential
can be obtained also with common xc approximations, as simple as the
LDA, when addressed from the ensemble perspective. The article therefore
highlights how capturing the relationship between KS and many-electron
energies with advanced xc approximations is crucial for accurately
calculating excitations, as well as the ground-state density and energy
of systems which consist of distinct subsystems.
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Affiliation(s)
- Eli Kraisler
- Fritz Haber Center for Molecular Dynamics and Institute of Chemistry, The Hebrew University of Jerusalem, 9091401 Jerusalem, Israel
| | - M J P Hodgson
- Department of Physics, Durham University, South Road, Durham DH1 3LE, United Kingdom.,Max-Planck-Institut für Mikrostrukturphysik, Weinberg 2, D-06120 Halle, Germany
| | - E K U Gross
- Fritz Haber Center for Molecular Dynamics and Institute of Chemistry, The Hebrew University of Jerusalem, 9091401 Jerusalem, Israel
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24
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Kretz B, Egger DA. Accurate Molecular Geometries in Complex Excited-State Potential Energy Surfaces from Time-Dependent Density Functional Theory. J Chem Theory Comput 2021; 17:357-366. [PMID: 33284603 DOI: 10.1021/acs.jctc.0c00858] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The interplay of electronic excitations and structural changes in molecules impacts nonradiative decay and charge transfer in the excited state, thus influencing excited-state lifetimes and photocatalytic reaction rates in optoelectronic and energy devices. To capture such effects requires computational methods providing an accurate description of excited-state potential energy surfaces and geometries. We suggest time-dependent density functional theory using optimally tuned range-separated hybrid (OT-RSH) functionals as an accurate approach to obtain excited-state molecular geometries. We show that OT-RSH provides accurate molecular geometries in excited-state potential energy surfaces that are complex and involve an interplay of local and charge-transfer excitations, for which conventional semilocal and hybrid functionals fail. At the same time, the nonempirical OT-RSH approach maintains the high accuracy of parametrized functionals (e.g., B3LYP) for predicting excited-state geometries of small organic molecules showing valence excited states.
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Affiliation(s)
- Bernhard Kretz
- Department of Physics, Technical University of Munich, James-Franck-Str. 1, 85748 Garching, Germany
| | - David A Egger
- Department of Physics, Technical University of Munich, James-Franck-Str. 1, 85748 Garching, Germany
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25
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Gao F, Tao D, Ju C, Yang BB, Bao XQ, Zhang D, Zhang TT, Li L. Regioselectivity of aminomethylation in 3-acetyl-7-hydroxycoumarins: Mannich bases and Betti bases. NEW J CHEM 2021. [DOI: 10.1039/d1nj01584b] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The atomic electron density distribution in 3-acetyl-7-hydroxycoumarin was analysed to elucidate the regioselectivity of aminomethylation.
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Affiliation(s)
- Fan Gao
- Beijing Key Laboratory of Active Substances Discovery and Druggability Evaluation
- Institute of Materia Medica
- Chinese Academy of Medical Sciences & Peking Union Medical College
- Beijing 100050
- China
| | - Deng Tao
- Beijing Key Laboratory of Active Substances Discovery and Druggability Evaluation
- Institute of Materia Medica
- Chinese Academy of Medical Sciences & Peking Union Medical College
- Beijing 100050
- China
| | - Cheng Ju
- Beijing Key Laboratory of Active Substances Discovery and Druggability Evaluation
- Institute of Materia Medica
- Chinese Academy of Medical Sciences & Peking Union Medical College
- Beijing 100050
- China
| | - Bei-Bei Yang
- Beijing Key Laboratory of Active Substances Discovery and Druggability Evaluation
- Institute of Materia Medica
- Chinese Academy of Medical Sciences & Peking Union Medical College
- Beijing 100050
- China
| | - Xiu-Qi Bao
- Beijing Key Laboratory of Active Substances Discovery and Druggability Evaluation
- Institute of Materia Medica
- Chinese Academy of Medical Sciences & Peking Union Medical College
- Beijing 100050
- China
| | - Dan Zhang
- Beijing Key Laboratory of Active Substances Discovery and Druggability Evaluation
- Institute of Materia Medica
- Chinese Academy of Medical Sciences & Peking Union Medical College
- Beijing 100050
- China
| | - Tian-Tai Zhang
- Beijing Key Laboratory of Active Substances Discovery and Druggability Evaluation
- Institute of Materia Medica
- Chinese Academy of Medical Sciences & Peking Union Medical College
- Beijing 100050
- China
| | - Li Li
- Beijing Key Laboratory of Active Substances Discovery and Druggability Evaluation
- Institute of Materia Medica
- Chinese Academy of Medical Sciences & Peking Union Medical College
- Beijing 100050
- China
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26
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Alipour M, Safari Z. Singlet fission relevant energetics from optimally tuned range-separated hybrids. Phys Chem Chem Phys 2020; 22:27060-27076. [PMID: 33215617 DOI: 10.1039/d0cp03951a] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
As a promising idea to design high-efficiency organic photovoltaics, singlet fission (SF) mechanism, i.e., generating two triplet excitons out of a single photon absorption, has recently come into the spotlight. Even though much effort has been devoted to this arena, accurately accounting for the SF process from the theoretical perspective has proven to be challenging. Herein, the SF energetics have thoroughly been investigated with the help of optimally tuned range-separated hybrid functionals (OT-RSHs) in both gas and solvent phases. Taking a series of experimentally known SF chromophores as working models, we have proposed and validated several variants of OT-RSH approximations for the reliable prediction of the energy levels which match the crucial criteria for the SF process, namely, the negative singlet-triplet and triplet-triplet energy gaps. We scrutinize the role of the OT-RSH ingredients, i.e., the underlying density functional approximations, short- and long-range exact-like exchange, as well as the range-separation parameter, for our purpose. The newly designed OT-RSHs outperform the standard RSHs and other related schemes such as screened-exchange approximations as well as other density functionals from different rungs for describing the SF energetics. More importantly, it is unveiled that although the OT-RSH coupled with the polarizable continuum model, OT-RSH-PCM, as well as the screened versions, OT-SRSHs, which account for the screening effect by the electron correlation through the scalar dielectric constant have some advantages over gas-phase computations using OT-RSHs, the energetics criteria of the SF process may not necessarily be satisfied. This in turn corroborates the idea of performing both the optimal tuning procedure and subsequent computations of the SF relevant energetics using OT-RSHs as a more reliable and affordable framework, at least for the present purpose. The applicability of the proposed models is also put into broader perspective, where they are used for the computational design of several chromophores as promising candidates prone to utilization in the SF-based materials. Hopefully, our recommended OT-RSHs can function as efficient models for both the theoretical modeling of SF chromophores and confirming the experimental observations in the field.
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Affiliation(s)
- Mojtaba Alipour
- Department of Chemistry, School of Science, Shiraz University, Shiraz 71946-84795, Iran.
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27
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Bhandari S, Yamada A, Hoskins A, Payne J, Aksu H, Dunietz BD. Achieving Predictive Description of Negative Differential Resistance in Molecular Junctions Using a Range‐Separated Hybrid Functional. ADVANCED THEORY AND SIMULATIONS 2020. [DOI: 10.1002/adts.202000016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Srijana Bhandari
- Department of Chemistry and Biochemistry Kent State University Kent OH 44242 USA
| | - Atsushi Yamada
- Department of Chemistry and Biochemistry Kent State University Kent OH 44242 USA
| | - Austin Hoskins
- Department of Chemistry and Biochemistry Kent State University Kent OH 44242 USA
| | - Jameson Payne
- Department of Chemistry and Biochemistry Kent State University Kent OH 44242 USA
| | - Huseyin Aksu
- Department of Chemistry and Biochemistry Kent State University Kent OH 44242 USA
- Department of Physics Canakkale Onsekiz Mart University Canakkale 17100 Turkey
| | - Barry D. Dunietz
- Department of Chemistry and Biochemistry Kent State University Kent OH 44242 USA
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28
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Aksu H, Paul SK, Herbert JM, Dunietz BD. How Well Does a Solvated Octa-acid Capsule Shield the Embedded Chromophore? A Computational Analysis Based on an Anisotropic Dielectric Continuum Model. J Phys Chem B 2020; 124:6998-7004. [PMID: 32787071 DOI: 10.1021/acs.jpcb.0c04032] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The optical properties of chromophores embedded in a water-solvated dimer of octa-acid that forms a molecular-shaped capsule are investigated. In particular, we address the anisotropic dielectric environment that appears to blue-shift excitation energies compared to the free aqueous chromophores. Recently we reported that using an effective scalar dielectric constant ε ≈ 3 appears to reproduce the measured spectra of the embedded coumarins, suggesting that the capsule provides a significant, albeit not perfect, screening of the aqueous dielectric environment. Here, we report absorption energies using a theoretical treatment that includes continuum solvation affected by an anisotropic dielectric function reflecting the high-dielectric environment outside of the capsule and the low-dielectric region within. We report time-dependent density functional theory calculations using a range-separated functional with the Poisson boundary conditions that model the anisotropic dielectric environment. Our calculations find that the anisotropic environment due to the water-solvated hydrophobic capsule is equivalent to a homogeneous effective dielectric constant of ≈3. The calculated values also appear to reproduce measured absorption of the embedded coumarin, where we study the effect of the hydrophobic capsule on the excited state.
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Affiliation(s)
- Huseyin Aksu
- Department of Physics, Canakkale Onsekiz Mart University, 17100 Canakkale, Turkey.,Department of Chemistry and Biochemistry, Kent State University, Kent, Ohio 44242, United States
| | - Suranjan K Paul
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
| | - John M Herbert
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
| | - Barry D Dunietz
- Department of Chemistry and Biochemistry, Kent State University, Kent, Ohio 44242, United States
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