1
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Dantas Filho RV, de Queiroz TB. Screened optimally tuned range separated hybrid functional for solvated low bandgap molecular systems. J Chem Phys 2024; 161:034109. [PMID: 39007381 DOI: 10.1063/5.0213688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2024] [Accepted: 06/27/2024] [Indexed: 07/16/2024] Open
Abstract
The description of electronic properties of low bandgap molecular system is often performed by using density functional theory (DFT) and time dependent (TD) DFT calculations with the optimally tuned range-separated hybrid (OT-RSH) functional, as it contains the necessary ingredients to reliably predict charge transfer excitations. However, the range separating parameter (ω) is system-dependent and its optimization, including the chemical environment, is intricate. Refaely-Abramson et al. demonstrated that the gap renormalization in molecular crystals, a ground state property, can be represented by an OT-RSH functional screened by ɛstatic [Phys. Rev. B 88, 081204(R) (2013)], the zero frequency scalar dielectric constant. In this study, we propose the use of an OT-RSH functional screened by the scalar dielectric constant in the high frequency limit (OT-sRSH), ɛ∞, an appropriate constraint for vertical ionization energies or excitations in a dielectric environment. We have performed calculations for S,N-heteroacene derivatives in tetrahydrofuran and dichloromethane. The "unscreened" OT-RSH functional tends to underestimate experimental ionization potentials (IPs) and optical gaps (Egs) by up to 1.5 and 0.5 eV, respectively. In contrast, OT-sRSH functional calculations underestimate IPs and Egs by only 0.4 and 0.2 eV. We also compared the OT-sRSH results to explicitly solvated OT-RSH functional calculations for oligothiophenes in dioxane, benzene in ammonia, and methylene blue in water. We observe that both the approaches perform similarly for weakly interacting intermolecular systems and deviate for solvent-solute interacting systems, as expected. In conclusion, the OT-sRSH functional can describe molecular systems with environmental polarization effects accurately, a step toward describing realistic molecular systems.
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Affiliation(s)
- Reinaldo V Dantas Filho
- Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, Av. dos Estados 5001, 09510-580 Santo André-SP, Brazil
| | - Thiago B de Queiroz
- Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, Av. dos Estados 5001, 09510-580 Santo André-SP, Brazil
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2
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Govindharaj P, Wierzba AJ, Kęska K, Kochman MA, Wiosna-Sałyga G, Kubas A, Data P, Lindner M. Regioisomerism vs Conformation: Impact of Molecular Design on the Emission Pathway in Organic Light-Emitting Device Emitters. ACS APPLIED MATERIALS & INTERFACES 2024; 16. [PMID: 38668584 PMCID: PMC11082840 DOI: 10.1021/acsami.3c19212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 04/14/2024] [Accepted: 04/17/2024] [Indexed: 05/12/2024]
Abstract
Despite the design and proposal of several new structural motifs as thermally activated delayed fluorescent (TADF) emitters for organic light-emitting device (OLED) applications, the nature of their interaction with the host matrix in the emissive layer of the device and their influence on observed photophysical outputs remain unclear. To address this issue, we present, for the first time, the use of up to four regioisomers bearing a donor-acceptor-donor electronic structure based on the desymmetrized naphthalene benzimidazole scaffold, equipped with various electron-donating units and possessing distinguished conformational lability. Quantum chemical calculations allow us to identify the most favorable conformations adopted by the electron-rich groups across the entire pool of regioisomers. These conformations were then compared with conformational changes caused by the interaction of the emitter with the Zeonex and 4,4'-bis(N-carbazolyl)-1,1'-biphenyl (CBP) matrices, and the correlation with observed photophysics was monitored by UV-vis absorption and steady-state photoluminescence spectra, combined with time-resolved spectroscopic techniques. Importantly, a CBP matrix was found to have a significant impact on the conformational change of regioisomers, leading to unique TADF emission mechanisms that encompass dual emission and inversion of the singlet-triplet excited-state energies and result in the enhancement of TADF efficiency. As a proof of concept, regioisomers with optimal donor positions were utilized to fabricate an OLED, revealing, with the best-performing dye, an external quantum emission of 11.6%, accompanied by remarkable luminance (28,000 cd/m2). These observations lay the groundwork for a better understanding of the role of the host matrix. In the long term, this new knowledge can lead to predicting the influence of the host matrix and adopting the structure of the emitter in a way that allows the development of highly efficient and efficient OLEDs.
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Affiliation(s)
- Prasannamani Govindharaj
- Department
of Molecular Physics, Faculty of Chemistry, Łódź University of Technology, Stefana Żeromskiego 114, 90-543 Łódź, Poland
| | - Aleksandra J. Wierzba
- Institute
of Organic Chemistry, Polish Academy of
Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland
| | - Karolina Kęska
- Institute
of Organic Chemistry, Polish Academy of
Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland
| | - Michał Andrzej Kochman
- Institute
of Physical Chemistry, Polish Academy of
Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland
| | - Gabriela Wiosna-Sałyga
- Department
of Molecular Physics, Faculty of Chemistry, Łódź University of Technology, Stefana Żeromskiego 114, 90-543 Łódź, Poland
| | - Adam Kubas
- Institute
of Physical Chemistry, Polish Academy of
Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland
| | - Przemysław Data
- Department
of Molecular Physics, Faculty of Chemistry, Łódź University of Technology, Stefana Żeromskiego 114, 90-543 Łódź, Poland
| | - Marcin Lindner
- Institute
of Organic Chemistry, Polish Academy of
Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland
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3
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Amblard D, Blase X, Duchemin I. Static versus dynamically polarizable environments within the many-body GW formalism. J Chem Phys 2024; 160:154104. [PMID: 38624115 DOI: 10.1063/5.0203637] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Accepted: 03/28/2024] [Indexed: 04/17/2024] Open
Abstract
Continuum- or discrete-polarizable models for the study of optoelectronic processes in embedded subsystems rely mostly on the restriction of the surrounding electronic dielectric response to its low frequency limit. Such a description hinges on the assumption that the electrons in the surrounding medium react instantaneously to any excitation in the central subsystem, thus treating the environment in the adiabatic limit. Exploiting a recently developed embedded GW formalism with an environment described at the fully ab initio level, we assess the merits of the adiabatic limit with respect to an environment where the full dynamics of the dielectric response are considered. Furthermore, we show how to properly take the static limit of the environment's susceptibility by introducing the so-called Coulomb-hole and screened-exchange contributions to the reaction field. As a first application, we consider a C60 molecule at the surface of a C60 crystal, namely, a case where the dynamics of the embedded and embedding subsystems are similar. The common adiabatic assumption, when properly treated, generates errors below 10% on the polarization energy associated with frontier energy levels and associated energy gaps. Finally, we consider a water molecule inside a metallic nanotube, the worst case for the environment's adiabatic limit. The error on the gap polarization energy remains below 10%, even though the error on the frontier orbital polarization energies can reach a few tenths of an electronvolt.
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Affiliation(s)
- David Amblard
- University Grenoble Alpes, CNRS, Inst NEEL, F-38042 Grenoble, France
| | - Xavier Blase
- University Grenoble Alpes, CNRS, Inst NEEL, F-38042 Grenoble, France
| | - Ivan Duchemin
- University Grenoble Alpes, CEA, IRIG-MEM-L_Sim, 38054 Grenoble, France
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4
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Di Maiolo F, Phan Huu DKA, Giavazzi D, Landi A, Racchi O, Painelli A. Shedding light on thermally-activated delayed fluorescence. Chem Sci 2024; 15:5434-5450. [PMID: 38638233 PMCID: PMC11023041 DOI: 10.1039/d4sc00033a] [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: 01/02/2024] [Accepted: 02/17/2024] [Indexed: 04/20/2024] Open
Abstract
Thermally activated delayed fluorescence (TADF) is a hot research topic in view of its impressive applications in a wide variety of fields from organic LEDs to photodynamic therapy and metal-free photocatalysis. TADF is a rare and fragile phenomenon that requires a delicate equilibrium between tiny singlet-triplet gaps, sizable spin-orbit couplings, conformational flexibility and a balanced contribution of charge transfer and local excited states. To make the picture more complex, this precarious equilibrium is non-trivially affected by the interaction of the TADF dye with its local environment. The concurrent optimization of the dye and of the embedding medium is therefore of paramount importance to boost practical applications of TADF. Towards this aim, refined theoretical and computational approaches must be cleverly exploited, paying attention to the reliability of adopted approximations. In this perspective, we will address some of the most important issues in the field. Specifically, we will critically review theoretical and computational approaches to TADF rates, highlighting the limits of widespread approaches. Environmental effects on the TADF photophysics are discussed in detail, focusing on the major role played by dielectric and conformational disorder in liquid solutions and amorphous matrices.
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Affiliation(s)
- Francesco Di Maiolo
- Dept. Chemistry, Life Science and Environmental Sustainability, University of Parma Parco Area delle Scienze 17/A 43124 Parma Italy
| | - D K Andrea Phan Huu
- Dept. Chemistry, Life Science and Environmental Sustainability, University of Parma Parco Area delle Scienze 17/A 43124 Parma Italy
| | - Davide Giavazzi
- Dept. Chemistry, Life Science and Environmental Sustainability, University of Parma Parco Area delle Scienze 17/A 43124 Parma Italy
| | - Andrea Landi
- Dept. Chemistry, Life Science and Environmental Sustainability, University of Parma Parco Area delle Scienze 17/A 43124 Parma Italy
| | - Ottavia Racchi
- Dept. Chemistry, Life Science and Environmental Sustainability, University of Parma Parco Area delle Scienze 17/A 43124 Parma Italy
| | - Anna Painelli
- Dept. Chemistry, Life Science and Environmental Sustainability, University of Parma Parco Area delle Scienze 17/A 43124 Parma Italy
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5
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Chen G, Swartzfager JR, Asbury JB. Matrix Dynamics and Their Crucial Role in Non-radiative Decay during Thermally Activated Delayed Fluorescence. J Am Chem Soc 2023; 145:25495-25504. [PMID: 37955854 DOI: 10.1021/jacs.3c11719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2023]
Abstract
We investigated the interplay of matrix dynamics with the molecular dynamics of a thermally activated delayed fluorescence (TADF) emitter, NAI-DMAC, to identify factors that influence the photophysical processes leading to TADF. The matrix dynamics surrounding NAI-DMAC molecules were varied continuously from the liquid to the solid state by depositing toluene solutions containing poly(methyl methacrylate) (PMMA) and NAI-DMAC onto optical substrates. We monitored changes of the NAI-DMAC emission as the liquid films dried to form solid PMMA films using temperature- and time-resolved photoluminescence spectroscopy. We observed that, in low-viscosity solutions, the proportion of delayed fluorescence from NAI-DMAC was much smaller than that of prompt fluorescence, indicating that negligible TADF occurred in the low-viscosity environment. However, as the viscosity of the environment diverged at the final stages of dry-down to form solid PMMA films, the delayed fluorescence component of NAI-DMAC emission was extended to longer time scales and increased in amplitude relative to prompt emission as the temperature increased─signatures that TADF occurred in the solid state as expected. Our findings reveal the influence that matrix dynamics have on the competition between conformational motion needed to access emissive states and undergo TADF versus larger amplitude structural fluctuations that lead to non-radiative decay. Insights from these studies will inform ongoing work to understand and predict how host matrices used in organic light-emitting devices can be designed to maximize the radiative properties of TADF emitters by allowing molecular motion needed to undergo TADF while restricting larger amplitude motion leading to non-radiative decay.
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Affiliation(s)
- Gary Chen
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - John R Swartzfager
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - John B Asbury
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
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6
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Bardi B, Giavazzi D, Ferrari E, Iagatti A, Di Donato M, Phan Huu DKA, Di Maiolo F, Sissa C, Masino M, Lapini A, Painelli A. Solid state solvation: a fresh view. MATERIALS HORIZONS 2023; 10:4172-4182. [PMID: 37522331 DOI: 10.1039/d3mh00988b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/01/2023]
Abstract
The design of efficient organic electronic devices, including OLEDs, OPVs, luminescent solar concentrators, etc., relies on the optimization of relevant materials, often constituted by an active (functional) dye embedded in a matrix. Understanding solid state solvation (SSS), i.e. how the properties of the active dye are affected by the matrix, is therefore an issue of fundamental and technological relevance. Here an extensive experimental and theoretical investigation is presented shedding light on this, somewhat controversial, topic. The spectral properties of the dye at equilibrium, i.e. absorption and Raman spectra, are not affected by the matrix dynamics. Reliable estimates of the matrix polarity are then obtained from an analysis of the micro-Raman spectra of polar dyes. Specifically, to establish a reliable polarity scale, the spectra of DCM or NR dispersed in amorphous matrices are compared with the spectra of the same dyes in liquid solvents with known polarity. On the other hand, steady-state emission spectra obtained in solid matrices depend in a highly non-trivial way on the matrix polarity and its dynamics. An extensive experimental and theoretical analysis of the time-resolved emission spectra of NR in a very large time window (15 fs-15 ns) allows us to validate this dye as a good probe of the dielectric dynamics of the surrounding medium. We provide a first assessment of the relaxation dynamics of two matrices (mCBPCN and DPEPO) of interest for OLED application, unambiguously demonstrating that the matrix readjusts for at least 15 ns after the dye photoexcitation.
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Affiliation(s)
- Brunella Bardi
- Dept. Chemistry, Life Science and Environmental Sustainability, University of Parma, Parco Area delle Scienze 17/A, 43124 Parma, Italy.
| | - Davide Giavazzi
- Dept. Chemistry, Life Science and Environmental Sustainability, University of Parma, Parco Area delle Scienze 17/A, 43124 Parma, Italy.
| | - Elena Ferrari
- Dept. Chemistry, Life Science and Environmental Sustainability, University of Parma, Parco Area delle Scienze 17/A, 43124 Parma, Italy.
| | - Alessandro Iagatti
- CNR-INO (Istituto Nazionaledi Ottica), Largo Fermi 6, 50125 Firenze, Italy
- LENS (European Laboratory for Non-Linear Spectroscopy), Via N. Carrara 1, 50019, Sesto Fiorentino, FI, Italy
| | - Mariangela Di Donato
- LENS (European Laboratory for Non-Linear Spectroscopy), Via N. Carrara 1, 50019, Sesto Fiorentino, FI, Italy
- ICCOM-CNR, via Madonna del Piano 10, I-50019 Sesto Fiorentino, FI, Italy
| | - D K Andrea Phan Huu
- Dept. Chemistry, Life Science and Environmental Sustainability, University of Parma, Parco Area delle Scienze 17/A, 43124 Parma, Italy.
| | - Francesco Di Maiolo
- Dept. Chemistry, Life Science and Environmental Sustainability, University of Parma, Parco Area delle Scienze 17/A, 43124 Parma, Italy.
| | - Cristina Sissa
- Dept. Chemistry, Life Science and Environmental Sustainability, University of Parma, Parco Area delle Scienze 17/A, 43124 Parma, Italy.
| | - Matteo Masino
- Dept. Chemistry, Life Science and Environmental Sustainability, University of Parma, Parco Area delle Scienze 17/A, 43124 Parma, Italy.
| | - Andrea Lapini
- Dept. Chemistry, Life Science and Environmental Sustainability, University of Parma, Parco Area delle Scienze 17/A, 43124 Parma, Italy.
- LENS (European Laboratory for Non-Linear Spectroscopy), Via N. Carrara 1, 50019, Sesto Fiorentino, FI, Italy
| | - Anna Painelli
- Dept. Chemistry, Life Science and Environmental Sustainability, University of Parma, Parco Area delle Scienze 17/A, 43124 Parma, Italy.
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7
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Bardi B, Vygranenko KV, Koszarna B, Vakuliuk O, Dobrzycki Ł, Gryko DT, Terenziani F, Painelli A. Novel Method for the Synthesis of Merocyanines: New Photophysical Possibilities for a Known Class of Fluorophores. Chemistry 2023; 29:e202300979. [PMID: 37203589 DOI: 10.1002/chem.202300979] [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: 03/28/2023] [Revised: 05/18/2023] [Accepted: 05/19/2023] [Indexed: 05/20/2023]
Abstract
A new, transformative method for the preparation of rhodols and other merocyanines from readily available tetrafluorohydroxybenzaldehyde and aminophenols has been developed. It is now possible to prepare merocyanines bearing three fluorine atoms and additional conjugated rings, and the whole one-pot process occurs under neutral, mild conditions. Three heretofore unknown merocyanine-based architectures were prepared using this strategy from aminonaphthols and 4-hydroxycoumarins. The ability to change the structure of original rhodol chromophore into π-expanded merocyanines translates to a comprehensive method for the modulation of photophysical properties, such as shifting the absorption and emission bands across almost the entire visible spectrum, reaching a huge Stokes shift i. e. 4800 cm-1 , brightness approximately 80.000 M-1 cm-1 , two-photon absorption cross-section above 150 GM and switching-on/off solvatofluorochromism. A detailed investigation allowed to rationalize the different spectroscopic behavior of rhodols and new merocyanines, addressing solvatochromism and two-photon absorption.
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Affiliation(s)
- Brunella Bardi
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 17/a, 43124, Parma, Italy
| | | | - Beata Koszarna
- Institute of Organic Chemistry Polish Academy of Sciences, Warsaw, Poland
| | - Olena Vakuliuk
- Institute of Organic Chemistry Polish Academy of Sciences, Warsaw, Poland
| | - Łukasz Dobrzycki
- Faculty of Chemistry, University of Warsaw, Żwirki i Wigury 101, 02-089, Warsaw, Poland
| | - Daniel T Gryko
- Institute of Organic Chemistry Polish Academy of Sciences, Warsaw, Poland
| | - Francesca Terenziani
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 17/a, 43124, Parma, Italy
| | - Anna Painelli
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 17/a, 43124, Parma, Italy
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8
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Bhat V, Callaway CP, Risko C. Computational Approaches for Organic Semiconductors: From Chemical and Physical Understanding to Predicting New Materials. Chem Rev 2023. [PMID: 37141497 DOI: 10.1021/acs.chemrev.2c00704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
While a complete understanding of organic semiconductor (OSC) design principles remains elusive, computational methods─ranging from techniques based in classical and quantum mechanics to more recent data-enabled models─can complement experimental observations and provide deep physicochemical insights into OSC structure-processing-property relationships, offering new capabilities for in silico OSC discovery and design. In this Review, we trace the evolution of these computational methods and their application to OSCs, beginning with early quantum-chemical methods to investigate resonance in benzene and building to recent machine-learning (ML) techniques and their application to ever more sophisticated OSC scientific and engineering challenges. Along the way, we highlight the limitations of the methods and how sophisticated physical and mathematical frameworks have been created to overcome those limitations. We illustrate applications of these methods to a range of specific challenges in OSCs derived from π-conjugated polymers and molecules, including predicting charge-carrier transport, modeling chain conformations and bulk morphology, estimating thermomechanical properties, and describing phonons and thermal transport, to name a few. Through these examples, we demonstrate how advances in computational methods accelerate the deployment of OSCsin wide-ranging technologies, such as organic photovoltaics (OPVs), organic light-emitting diodes (OLEDs), organic thermoelectrics, organic batteries, and organic (bio)sensors. We conclude by providing an outlook for the future development of computational techniques to discover and assess the properties of high-performing OSCs with greater accuracy.
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Affiliation(s)
- Vinayak Bhat
- Department of Chemistry & Center for Applied Energy Research, University of Kentucky, Lexington, Kentucky 40506-0055, United States
| | - Connor P Callaway
- Department of Chemistry & Center for Applied Energy Research, University of Kentucky, Lexington, Kentucky 40506-0055, United States
| | - Chad Risko
- Department of Chemistry & Center for Applied Energy Research, University of Kentucky, Lexington, Kentucky 40506-0055, United States
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9
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Swathi K, Sujith M, Divya PS, P MV, Delledonne A, Phan Huu DKA, Di Maiolo F, Terenziani F, Lapini A, Painelli A, Sissa C, Thomas KG. From symmetry breaking to symmetry swapping: is Kasha's rule violated in multibranched phenyleneethynylenes? Chem Sci 2023; 14:1986-1996. [PMID: 36845926 PMCID: PMC9945429 DOI: 10.1039/d2sc05206g] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2022] [Accepted: 01/12/2023] [Indexed: 01/15/2023] Open
Abstract
The phenomenon of excited-state symmetry breaking is often observed in multipolar molecular systems, significantly affecting their photophysical and charge separation behavior. As a result of this phenomenon, the electronic excitation is partially localized in one of the molecular branches. However, the intrinsic structural and electronic factors that regulate excited-state symmetry breaking in multibranched systems have hardly been investigated. Herein, we explore these aspects by adopting a joint experimental and theoretical investigation for a class of phenyleneethynylenes, one of the most widely used molecular building blocks for optoelectronic applications. The large Stokes shifts observed for highly symmetric phenyleneethynylenes are explained by the presence of low-lying dark states, as also established by two-photon absorption measurements and TDDFT calculations. In spite of the presence of low-lying dark states, these systems show an intense fluorescence in striking contrast to Kasha's rule. This intriguing behavior is explained in terms of a novel phenomenon, dubbed "symmetry swapping" that describes the inversion of the energy order of excited states, i.e., the swapping of excited states occurring as a consequence of symmetry breaking. Thus, symmetry swapping explains quite naturally the observation of an intense fluorescence emission in molecular systems whose lowest vertical excited state is a dark state. In short, symmetry swapping is observed in highly symmetric molecules having multiple degenerate or quasi-degenerate excited states that are prone to symmetry breaking.
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Affiliation(s)
- K. Swathi
- Dipartimento di Scienze Chimiche, della Vita e della Sostenibilità Ambientale, Università di ParmaParco Area delle Scienze 17A43124ParmaItaly,School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram (IISER TVM)VithuraThiruvananthapuram695 551India
| | - Meleppatt Sujith
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram (IISER TVM) Vithura Thiruvananthapuram 695 551 India
| | - P. S. Divya
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram (IISER TVM)VithuraThiruvananthapuram695 551India
| | - Merin Varghese P
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram (IISER TVM) Vithura Thiruvananthapuram 695 551 India
| | - Andrea Delledonne
- Dipartimento di Scienze Chimiche, della Vita e della Sostenibilità Ambientale, Università di Parma Parco Area delle Scienze 17A 43124 Parma Italy
| | - D. K. Andrea Phan Huu
- Dipartimento di Scienze Chimiche, della Vita e della Sostenibilità Ambientale, Università di ParmaParco Area delle Scienze 17A43124ParmaItaly
| | - Francesco Di Maiolo
- Dipartimento di Scienze Chimiche, della Vita e della Sostenibilità Ambientale, Università di Parma Parco Area delle Scienze 17A 43124 Parma Italy
| | - Francesca Terenziani
- Dipartimento di Scienze Chimiche, della Vita e della Sostenibilità Ambientale, Università di Parma Parco Area delle Scienze 17A 43124 Parma Italy
| | - Andrea Lapini
- Dipartimento di Scienze Chimiche, della Vita e della Sostenibilità Ambientale, Università di Parma Parco Area delle Scienze 17A 43124 Parma Italy
| | - Anna Painelli
- Dipartimento di Scienze Chimiche, della Vita e della Sostenibilità Ambientale, Università di Parma Parco Area delle Scienze 17A 43124 Parma Italy
| | - Cristina Sissa
- Dipartimento di Scienze Chimiche, della Vita e della Sostenibilità Ambientale, Università di Parma Parco Area delle Scienze 17A 43124 Parma Italy
| | - K. George Thomas
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram (IISER TVM)VithuraThiruvananthapuram695 551India
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10
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Swartzfager JR, Chen G, Francese T, Galli G, Asbury JB. Interplay of molecular dynamics and radiative decay of a TADF emitter in a glass-forming liquid. Phys Chem Chem Phys 2023; 25:3151-3159. [PMID: 36621848 DOI: 10.1039/d2cp05138a] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
We investigate the role of molecular dynamics in the luminescent properties of a prototypical thermally activated delayed fluorescence (TADF) emitter, NAI-DMAC, in solution using a combination of temperature dependent time-resolved photoluminescence and absorption spectroscopies. We use a glass forming liquid, 2-methylfuran, to introduce an abrupt change in the temperature dependent diffusion dynamics of the solvent and examine the influence this has on the emission intensity of NAI-DMAC molecules. Comparison of experiment with first principles molecular dynamics simulations reveals that the emission intensity of NAI-DMAC molecules follows the temperature-dependent self-diffusion dynamics of the solvent. A marked reduction of emission intensity is observed as the temperature decreases toward the glass transition because the rate at which NAI-DMAC molecules can access emissive molecular conformations is greatly reduced. Below the glass transition, the diffusion dynamics of the solvent changes more slowly with temperature, which causes the emission intensity to decrease more slowly as well. The combination of experiment and computation suggests a pathway by which TADF emitters may transiently access a distribution of conformational states and avoid the need for an average conformation that strikes a balance between lower singlet-triplet energy splittings versus higher emission probabilities.
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Affiliation(s)
- John R Swartzfager
- Department of Chemistry, The Pennsylvania State University, University Park, PA, 16802, USA.
| | - Gary Chen
- Department of Chemistry, The Pennsylvania State University, University Park, PA, 16802, USA.
| | - Tommaso Francese
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL, 60637, USA
| | - Giulia Galli
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL, 60637, USA.,Materials Science Division and Center for Molecular Engineering, Argonne National Laboratory, Lemont, IL, 60439, USA.,Department of Chemistry, University of Chicago, Chicago, IL, 60637, USA
| | - John B Asbury
- Department of Chemistry, The Pennsylvania State University, University Park, PA, 16802, USA.
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11
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Phan Huu DKA, Saseendran S, Dhali R, Franca LG, Stavrou K, Monkman A, Painelli A. Thermally Activated Delayed Fluorescence: Polarity, Rigidity, and Disorder in Condensed Phases. J Am Chem Soc 2022; 144:15211-15222. [PMID: 35944182 PMCID: PMC9413221 DOI: 10.1021/jacs.2c05537] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
We present a detailed and comprehensive picture of the photophysics of thermally activated delayed fluorescence (TADF). The approach relies on a few-state model, parametrized ab initio on a prototypical TADF dye, that explicitly accounts for the nonadiabatic coupling between electrons and vibrational and conformational motion, crucial to properly address (reverse) intersystem crossing rates. The Onsager model is exploited to account for the medium polarity and polarizability, with careful consideration of the different time scales of relevant degrees of freedom. TADF photophysics is then quantitatively addressed in a coherent and exhaustive approach that accurately reproduces the complex temporal evolution of emission spectra in liquid solvents as well as in solid organic matrices. The different rigidity of the two environments is responsible for the appearance in matrices of important inhomogeneous broadening phenomena that are ascribed to the intertwined contribution from (quasi)static conformational and dielectric disorder.
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Affiliation(s)
- D K Andrea Phan Huu
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, 43124 Parma, Italy
| | - Sangeeth Saseendran
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, 43124 Parma, Italy
| | - Rama Dhali
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, 43124 Parma, Italy
| | | | - Kleitos Stavrou
- Department of Physics, Durham University, South Road, Durham DH1 3LE, U.K
| | - Andrew Monkman
- Department of Physics, Durham University, South Road, Durham DH1 3LE, U.K
| | - Anna Painelli
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, 43124 Parma, Italy
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12
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Hall D, Sancho-García JC, Pershin A, Ricci G, Beljonne D, Zysman-Colman E, Olivier Y. Modeling of Multiresonant Thermally Activated Delayed Fluorescence Emitters─Properly Accounting for Electron Correlation Is Key! J Chem Theory Comput 2022; 18:4903-4918. [PMID: 35786892 DOI: 10.1021/acs.jctc.2c00141] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
With the surge of interest in multiresonant thermally activated delayed fluorescent (MR-TADF) materials, it is important that there exist computational methods to accurately model their excited states. Here, building on our previous work, we demonstrate how the spin-component scaling second-order approximate coupled-cluster (SCS-CC2), a wavefunction-based method, is robust at predicting the ΔEST (i.e., the energy difference between the lowest singlet S1 and triplet T1 excited states) of a large number of MR-TADF materials, with a mean average deviation (MAD) of 0.04 eV compared to experimental data. Time-dependent density functional theory calculations with the most common DFT functionals as well as the consideration of the Tamm-Dancoff approximation (TDA) consistently predict a much larger ΔEST as a result of a poorer account of Coulomb correlation as compared to SCS-CC2. Very interestingly, the use of a metric to assess the importance of higher order excitations in the SCS-CC2 wavefunctions shows that Coulomb correlation effects are substantially larger in the lowest singlet compared to the corresponding triplet and need to be accounted for a balanced description of the relevant electronic excited states. This is further highlighted with coupled cluster singles-only calculations, which predict very different S1 energies as compared to SCS-CC2 while T1 energies remain similar, leading to very large ΔEST, in complete disagreement with the experiments. We compared our SCS-CC2/cc-pVDZ with other wavefunction approaches, namely, CC2/cc-pVDZ and SOS-CC2/cc-pVDZ leading to similar performances. Using SCS-CC2, we investigate the excited-state properties of MR-TADF emitters showcasing large ΔET2T1 for the majority of emitters, while π-electron extension emerges as the best strategy to minimize ΔEST. We also employed SCS-CC2 to evaluate donor-acceptor systems that contain a MR-TADF moiety acting as the acceptor and show that the broad emission observed for some of these compounds arises from the solvent-promoted stabilization of a higher-lying charge-transfer singlet state (S2). This work highlights the importance of using wavefunction methods in relation to MR-TADF emitter design and associated photophysics.
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Affiliation(s)
- David Hall
- Organic Semiconductor Centre, EaStCHEM School of Chemistry, University of St Andrews, KY16 9ST St Andrews, U.K.,Laboratory for Chemistry of Novel Materials, University of Mons, 7000 Mons, Belgium
| | | | - Anton Pershin
- Wigner Research Centre for Physics, P.O. Box 49,Budapest 1121, Hungary
| | - Gaetano Ricci
- Laboratory for Computational Modeling of Functional Materials, Namur Institute of Structured Matter, Université de Namur, Rue de Bruxelles, 61, 5000 Namur, Belgium
| | - David Beljonne
- Laboratory for Chemistry of Novel Materials, University of Mons, 7000 Mons, Belgium
| | - Eli Zysman-Colman
- Organic Semiconductor Centre, EaStCHEM School of Chemistry, University of St Andrews, KY16 9ST St Andrews, U.K
| | - Yoann Olivier
- Laboratory for Computational Modeling of Functional Materials, Namur Institute of Structured Matter, Université de Namur, Rue de Bruxelles, 61, 5000 Namur, Belgium
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13
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Delledonne A, Orlandini M, Mazzeo PP, Sissa C, Bacchi A, Terenziani F, Pelagatti P. Bis-isonicotinoyl linkers containing polyaromatic scaffolds: synthesis, structure and spectroscopic properties. Phys Chem Chem Phys 2021; 24:1191-1201. [PMID: 34932053 DOI: 10.1039/d1cp04438a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In this study, a new series of extended linkers containing different polyaromatic chromophores (biphenyl, naphthalene, anthracene, fluorene, 9,9-dimethylfluorene and fluorenone) functionalized with isonicotinoyl moieties have been synthesized by Pd-catalyzed cross-coupling reactions involving isonicotinamide and the appropriate aromatic dibromide. The optimized protocol led to the isolation of the target molecules in good yield and with high purity. These were characterized by 1H NMR, FTIR, MS, and elemental analysis and their solid state structures were solved by single-crystal X-ray diffraction analysis. Electronic absorption and emission spectra were collected both in solution (DMF) and in the solid state. TDDFT calculations were carried out to investigate the effect of the isonicotinoyl moieties on the spectral features of the central chromophores. Although in solution only the linker containing a fluorenone scaffold shows a weak fluorescence, all the isolated linkers turned out to be fluorescent in the solid state, thus paving the way for their use for the fabrication of fluorescent MOFs.
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Affiliation(s)
- Andrea Delledonne
- Department of Chemical Sciences, Life Science and Environmental Sustainability, University of Parma, Parco Area delle Scienze 17/A, 43124 Parma, Italy.
| | - Martina Orlandini
- Department of Chemical Sciences, Life Science and Environmental Sustainability, University of Parma, Parco Area delle Scienze 17/A, 43124 Parma, Italy.
| | - Paolo P Mazzeo
- Department of Chemical Sciences, Life Science and Environmental Sustainability, University of Parma, Parco Area delle Scienze 17/A, 43124 Parma, Italy. .,Biopharmanet-TEC, University of Parma, Parco Area delle Scienze 27/A, 43124 Parma, Italy
| | - Cristina Sissa
- Department of Chemical Sciences, Life Science and Environmental Sustainability, University of Parma, Parco Area delle Scienze 17/A, 43124 Parma, Italy.
| | - Alessia Bacchi
- Department of Chemical Sciences, Life Science and Environmental Sustainability, University of Parma, Parco Area delle Scienze 17/A, 43124 Parma, Italy. .,Biopharmanet-TEC, University of Parma, Parco Area delle Scienze 27/A, 43124 Parma, Italy
| | - Francesca Terenziani
- Department of Chemical Sciences, Life Science and Environmental Sustainability, University of Parma, Parco Area delle Scienze 17/A, 43124 Parma, Italy.
| | - Paolo Pelagatti
- Department of Chemical Sciences, Life Science and Environmental Sustainability, University of Parma, Parco Area delle Scienze 17/A, 43124 Parma, Italy. .,CIRCC, Interuniversity Consortium of Chemical Reactivity and Catalysis, via Celso Ulpiani 27, 70126 Bari, Italy
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14
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Santoro F, Green JA, Martinez-Fernandez L, Cerezo J, Improta R. Quantum and semiclassical dynamical studies of nonadiabatic processes in solution: achievements and perspectives. Phys Chem Chem Phys 2021; 23:8181-8199. [PMID: 33875988 DOI: 10.1039/d0cp05907b] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
We concisely review the main methodological approaches to model nonadiabatic dynamics in isotropic solutions and their applications. Three general classes of models are identified as the most used to include solvent effects in the simulations. The first model describes the solvent as a set of harmonic collective modes coupled to the solute degrees of freedom, and the second as a continuum, while the third explicitly includes solvent molecules in the calculations. The issues related to the use of these models in semiclassical and quantum dynamical simulations are discussed, as well as the main limitations and perspectives of each approach.
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Affiliation(s)
- Fabrizio Santoro
- CNR-Consiglio Nazionale delle Ricerche, Istituto di Chimica dei Composti Organo Metallici (ICCOM-CNR), SS di Pisa, Area della Ricerca, via G. Moruzzi 1, I-56124 Pisa, Italy.
| | - James A Green
- CNR-Consiglio Nazionale delle Ricerche, Istituto di Biostrutture e Bioimmagini (IBB-CNR), via Mezzocannone 16, I-80136 Napoli, Italy.
| | - Lara Martinez-Fernandez
- Departamento de Química, Facultad de Ciencias and Institute for Advanced Research in Chemistry (IADCHEM), Universidad Autónoma de Madrid, Campus de Excelencia UAM-CSIC, 28049 Madrid, Spain
| | - Javier Cerezo
- Departamento de Química, Facultad de Ciencias and Institute for Advanced Research in Chemistry (IADCHEM), Universidad Autónoma de Madrid, Campus de Excelencia UAM-CSIC, 28049 Madrid, Spain
| | - Roberto Improta
- CNR-Consiglio Nazionale delle Ricerche, Istituto di Biostrutture e Bioimmagini (IBB-CNR), via Mezzocannone 16, I-80136 Napoli, Italy.
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15
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Dhali R, Phan Huu DKA, Terenziani F, Sissa C, Painelli A. Thermally activated delayed fluorescence: A critical assessment of environmental effects on the singlet-triplet energy gap. J Chem Phys 2021; 154:134112. [PMID: 33832272 DOI: 10.1063/5.0042058] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The effective design of dyes optimized for thermally activated delayed fluorescence (TADF) requires the precise control of two tiny energies: the singlet-triplet gap, which has to be maintained within thermal energy, and the strength of spin-orbit coupling. A subtle interplay among low-energy excited states having dominant charge-transfer and local character then governs TADF efficiency, making models for environmental effects both crucial and challenging. The main message of this paper is a warning to the community of chemists, physicists, and material scientists working in the field: the adiabatic approximation implicitly imposed to the treatment of fast environmental degrees of freedom in quantum-classical and continuum solvation models leads to uncontrolled results. Several approximation schemes were proposed to mitigate the issue, but we underline that the adiabatic approximation to fast solvation is inadequate and cannot be improved; rather, it must be abandoned in favor of an antiadiabatic approach.
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Affiliation(s)
- Rama Dhali
- Department of Chemistry, Life Science and Environmental Sustainability, University of Parma, Parma, Italy
| | - D K Andrea Phan Huu
- Department of Chemistry, Life Science and Environmental Sustainability, University of Parma, Parma, Italy
| | - Francesca Terenziani
- Department of Chemistry, Life Science and Environmental Sustainability, University of Parma, Parma, Italy
| | - Cristina Sissa
- Department of Chemistry, Life Science and Environmental Sustainability, University of Parma, Parma, Italy
| | - Anna Painelli
- Department of Chemistry, Life Science and Environmental Sustainability, University of Parma, Parma, Italy
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16
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Dhali R, Phan Huu DKA, Bertocchi F, Sissa C, Terenziani F, Painelli A. Understanding TADF: a joint experimental and theoretical study of DMAC-TRZ. Phys Chem Chem Phys 2021; 23:378-387. [DOI: 10.1039/d0cp05982j] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
TADF offers a promising way to harvest triplets in OLED for improved efficiency. To concurrently optimize the dye inside the matrix, a thorough experimental and theoretical study is presented of a the TADF dye addressing environmental effects.
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Affiliation(s)
- Rama Dhali
- Department of Chemistry
- Life Science and Environmental Sustainability
- University of Parma
- 43124 Parma
- Italy
| | - D. K. Andrea Phan Huu
- Department of Chemistry
- Life Science and Environmental Sustainability
- University of Parma
- 43124 Parma
- Italy
| | - Francesco Bertocchi
- Department of Chemistry
- Life Science and Environmental Sustainability
- University of Parma
- 43124 Parma
- Italy
| | - Cristina Sissa
- Department of Chemistry
- Life Science and Environmental Sustainability
- University of Parma
- 43124 Parma
- Italy
| | - Francesca Terenziani
- Department of Chemistry
- Life Science and Environmental Sustainability
- University of Parma
- 43124 Parma
- Italy
| | - Anna Painelli
- Department of Chemistry
- Life Science and Environmental Sustainability
- University of Parma
- 43124 Parma
- Italy
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17
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Blase X, Duchemin I, Jacquemin D, Loos PF. The Bethe-Salpeter Equation Formalism: From Physics to Chemistry. J Phys Chem Lett 2020; 11:7371-7382. [PMID: 32787315 DOI: 10.1021/acs.jpclett.0c01875] [Citation(s) in RCA: 70] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The Bethe-Salpeter equation (BSE) formalism is steadily asserting itself as a new efficient and accurate tool in the ensemble of computational methods available to chemists in order to predict optical excitations in molecular systems. In particular, the combination of the so-called GW approximation, giving access to reliable ionization energies and electron affinities, and the BSE formalism, able to model UV/vis spectra, has shown to provide accurate singlet excitation energies with a typical error of 0.1-0.3 eV. With a similar computational cost as time-dependent density-functional theory (TD-DFT), BSE is able to provide an accuracy on par with the most accurate global and range-separated hybrid functionals without the unsettling choice of the exchange-correlation functional, resolving further known issues (e.g., charge-transfer excitations). In this Perspective, we provide a historical overview of BSE, with a particular focus on its condensed-matter roots. We also propose a critical review of its strengths and weaknesses in different chemical situations.
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Affiliation(s)
- Xavier Blase
- Université Grenoble Alpes, CNRS, Institut NEEL, F-38042 Grenoble, France
| | - Ivan Duchemin
- Université Grenoble Alpes, CEA, IRIG-MEM-L Sim, 38054 Grenoble, France
| | - Denis Jacquemin
- Université de Nantes, CNRS, CEISAM UMR 6230, F-44000 Nantes, France
| | - Pierre-François Loos
- Laboratoire de Chimie et Physique Quantiques, Université de Toulouse, CNRS, UPS, Toulouse, France
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18
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Phan Huu DKA, Sissa C, Terenziani F, Painelli A. Optical spectra of organic dyes in condensed phases: the role of the medium polarizability. Phys Chem Chem Phys 2020; 22:25483-25491. [DOI: 10.1039/d0cp04496b] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
An effective model is presented to account for the effects of the medium electronic polarizability on spectral properties and on symmetry-breaking phenomena in charge-transfer dyes.
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Affiliation(s)
- D. K. Andrea Phan Huu
- Department of Chemistry
- Life Science and Environmental Sustainability
- Parma University
- 43124 Parma
- Italy
| | - Cristina Sissa
- Department of Chemistry
- Life Science and Environmental Sustainability
- Parma University
- 43124 Parma
- Italy
| | - Francesca Terenziani
- Department of Chemistry
- Life Science and Environmental Sustainability
- Parma University
- 43124 Parma
- Italy
| | - Anna Painelli
- Department of Chemistry
- Life Science and Environmental Sustainability
- Parma University
- 43124 Parma
- Italy
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