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Radenković S, Đorđević S, Nikolendžić M. Effect of Benzo-Annelation on Triplet State Energies in Polycyclic Conjugated Hydrocarbons. Chemistry 2024; 30:e202400361. [PMID: 38488676 DOI: 10.1002/chem.202400361] [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: 01/27/2024] [Indexed: 04/09/2024]
Abstract
In a series of earlier studies, the effect of benzo-annelation was found to be a useful tool for tuning the aromaticity in polycyclic conjugated compounds to desired level. In this work we studied the (anti)aromaticity of benzo-annelated derivatives of three conjugated hydrocarbons (anthracene, fluoranthene and biphenylene) in their lowest lying singlet (S0) and triplet (T1) states by means of the energy effect (ef), harmonic oscillator model of aromaticity (HOMA), multicentre delocalization indices (MCI), magnetically induced current densities (MICDs) and nucleus independent chemical shifts (NICS). We showed that benzo-annelation is a topology-based effect which can be used to modify the T1 state excitation energies (E(T1)). A quantitative model was established being able to accurately predict the E(T1) based only on the numbers of angularly, linearly and geminally annelated benzene rings. In addition, it was demonstrated that the E(T1) can be directly related to the (anti)aromatic character of the central ring in the studied molecules in their S0 state.
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Affiliation(s)
- Slavko Radenković
- University of Kragujevac, Faculty of Science, P.O. Box 60, Kragujevac, 34000, Serbia
| | - Slađana Đorđević
- University of Kragujevac, Faculty of Science, P.O. Box 60, Kragujevac, 34000, Serbia
| | - Marijana Nikolendžić
- University of Kragujevac, Faculty of Science, P.O. Box 60, Kragujevac, 34000, Serbia
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2
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Stasyuk OA, Voityuk AA, Stasyuk AJ. Facilitating Electron Transfer by Resizing Cyclocarbon Acceptor from C 18 to C 16. Chemistry 2024; 30:e202400215. [PMID: 38530218 DOI: 10.1002/chem.202400215] [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: 01/17/2024] [Revised: 03/25/2024] [Accepted: 03/26/2024] [Indexed: 03/27/2024]
Abstract
Recent advances in synthetic methods, combined with tip-induced on-surface chemistry, have enabled the formation of numerous cyclocarbon molecules. Here, we investigate computationally the experimentally studied C16 and C18 molecules as well as their van der Waals (vdW) complexes with several typical donor and acceptor molecules. Our results demonstrate a remarkable electron-withdrawing ability of cyclocarbon molecules. The vdW complexes of C16 and C18 exhibit a thermodynamically favorable photoinduced electron transfer (ET) from the donor partner to the cyclocarbons that occurs on a picosecond time scale. The lower reorganization energy of C16 compared to C18 leads to a significant acceleration of the ET reactions.
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Affiliation(s)
- O A Stasyuk
- Institut de Química Computacional i Catàlisi and Departament de Química, Universitat de Girona, C/ Maria Aurèlia, Capmany 69, 17003, Girona, Catalonia, Spain
| | - A A Voityuk
- Institut de Química Computacional i Catàlisi and Departament de Química, Universitat de Girona, C/ Maria Aurèlia, Capmany 69, 17003, Girona, Catalonia, Spain
| | - A J Stasyuk
- Institut de Química Computacional i Catàlisi and Departament de Química, Universitat de Girona, C/ Maria Aurèlia, Capmany 69, 17003, Girona, Catalonia, Spain
- Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093, Warsaw, Poland
- Departament de Farmàcia, i Tecnologia Farmacèutica, i Fisicoquímica, Facultat de Farmàcia i Ciències de l'Alimentació, Universitat de Barcelona (UB), Barcelona, Spain
- Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona (UB), Barcelona, Spain
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3
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Ferrão LFA, Pontes MAP, Fernandes GFS, Bettanin F, Aquino AJA, Lischka H, Nachtigallova D, Machado FBC. Stability and Reactivity of the Phenalene and Olympicene Isomers. J Phys Chem A 2023; 127:9430-9441. [PMID: 37920974 DOI: 10.1021/acs.jpca.3c04331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2023]
Abstract
The phenalene (triangulene) and olympicene molecules belong to the polycyclic aromatic hydrocarbon class, which have attracted substantial technological interest due to their unique electronic properties. Electronic structure calculations serve as a valuable tool in investigating the stability and reactivity of these molecular systems. In the present work, the multireference calculations, namely, the complete active space second-order perturbation theory and multireference averaged quadratic coupled cluster (MR-AQCC), were employed to study the reactivity and stability of phenalene and olympicene isomers, as well as their modified structures where the sp3-carbon at the borders were removed. The harmonic oscillator model of aromaticity (HOMA) and the nucleus-independent chemical shift as geometric and magnetic indexes calculated with density functional theory were utilized to assess the aromaticity of the studied molecules. These indexes were compared with properties such as the excitation energy and natural orbitals occupation. The reactivity analyzed using the HOMA index combined with MR-AQCC revealed the radical character of certain structures as well as the weakening of their aromaticity. Moreover, the results suggest that the removal of sp3-carbon atoms and the addition of hydrogen atoms did not alter the π network and the excitation energies of the phenalene molecules.
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Affiliation(s)
- Luiz F A Ferrão
- Departamento de Química, Instituto Tecnológico de Aeronáutica, São José dos Campos 122228-900, SP, Brazil
| | - Marcelo A P Pontes
- Departamento de Química, Instituto Tecnológico de Aeronáutica, São José dos Campos 122228-900, SP, Brazil
| | - Gabriel F S Fernandes
- Departamento de Química, Instituto Tecnológico de Aeronáutica, São José dos Campos 122228-900, SP, Brazil
| | - Fernanda Bettanin
- Escola de Artes, Ciências e Humanidades (EACH) - Universidade de São Paulo (USP), São Paulo 03828-000, SP, Brazil
| | - Adélia J A Aquino
- Department of Mechanical Engineering, Texas Tech University, Lubbock, Texas 79409, United States
| | - Hans Lischka
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409-1061, United States
| | - Dana Nachtigallova
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nam. 2, CZ-16610 Prague 6, Czech Republic
- IT4Innovations, VŠB-Technical University of Ostrava, 17. listopadu 2172/15, 70800 Ostrava-Poruba, Czech Republic
| | - Francisco B C Machado
- Departamento de Química, Instituto Tecnológico de Aeronáutica, São José dos Campos 122228-900, SP, Brazil
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Bennett TLR, Marsh AV, Turner JM, Plasser F, Heeney M, Glöcklhofer F. Functionalisation of conjugated macrocycles with type I and II concealed antiaromaticity via cross-coupling reactions. MOLECULAR SYSTEMS DESIGN & ENGINEERING 2023; 8:713-720. [PMID: 37288099 PMCID: PMC10243434 DOI: 10.1039/d3me00045a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Accepted: 05/03/2023] [Indexed: 06/09/2023]
Abstract
Conjugated macrocycles can exhibit concealed antiaromaticity; that is, despite not being antiaromatic, under specific circumstances, they can display properties typically observed in antiaromatic molecules due to their formal macrocyclic 4n π-electron system. Paracyclophanetetraene (PCT) and its derivatives are prime examples of macrocycles exhibiting this behaviour. In redox reactions and upon photoexcitation, they have been shown to behave like antiaromatic molecules (requiring type I and II concealed antiaromaticity, respectively), with such phenomena showing potential for use in battery electrode materials and other electronic applications. However, further exploration of PCTs has been hindered by the lack of halogenated molecular building blocks that would permit their integration into larger conjugated molecules by cross-coupling reactions. Here, we present two dibrominated PCTs, obtained as a mixture of regioisomers from a three-step synthesis, and demonstrate their functionalisation via Suzuki cross-coupling reactions. Optical, electrochemical, and theoretical studies reveal that aryl substituents can subtly tune the properties and behaviour of PCT, showing that this is a viable strategy in further exploring this promising class of materials.
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Affiliation(s)
- Troy L R Bennett
- Department of Chemistry and Centre for Processable Electronics, Imperial College London, Molecular Sciences Research Hub London UK
| | - Adam V Marsh
- KAUST Solar Center (KSC), Physical Science and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST) Thuwal Saudi Arabia
| | - James M Turner
- Department of Chemistry, Loughborough University Loughborough LE11 3TU UK
| | - Felix Plasser
- Department of Chemistry, Loughborough University Loughborough LE11 3TU UK
| | - Martin Heeney
- Department of Chemistry and Centre for Processable Electronics, Imperial College London, Molecular Sciences Research Hub London UK
- KAUST Solar Center (KSC), Physical Science and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST) Thuwal Saudi Arabia
| | - Florian Glöcklhofer
- Department of Chemistry and Centre for Processable Electronics, Imperial College London, Molecular Sciences Research Hub London UK
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5
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Rahav Y, Rajagopal SK, Dishi O, Bogoslavsky B, Gidron O. Alternating behavior in furan-acetylene macrocycles reveals the size-dependency of Hückel's rule in neutral molecules. Commun Chem 2023; 6:100. [PMID: 37244950 DOI: 10.1038/s42004-023-00902-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Accepted: 05/15/2023] [Indexed: 05/29/2023] Open
Abstract
Aromaticity can be assigned by Hückel's rule, which predicts that planar rings with delocalized (4n + 2) π-electrons are aromatic, whereas those with 4n π-electrons are antiaromatic. However, for neutral rings, the maximal value of "n" to which Hückel's rule applies remains unknown. Large macrocycles exhibiting global ring current can serve as models for addressing this question, but the global ring current are often overshadowed in these molecules by the local ring current of the constituent units. Here, we present a series of furan-acetylene macrocycles, ranging from the pentamer to octamer, whose neutral states display alternating contributions from global aromatic and antiaromatic ring currents. We find that the odd-membered macrocycles display global aromatic characteristics, whereas the even-membered macrocycles display contributions from globally antiaromatic ring current. These factors are expressed electronically (oxidation potentials), optically (emission spectra), and magnetically (chemical shifts), and DFT calculations predict global ring current alternations up to 54 π-electrons.
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Affiliation(s)
- Yuval Rahav
- Institute of Chemistry, The Center for Nanoscience and Nanotechnology, Casali Center for Applied Chemistry, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Jerusalem, 9190401, Israel
| | - Shinaj K Rajagopal
- Institute of Chemistry, The Center for Nanoscience and Nanotechnology, Casali Center for Applied Chemistry, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Jerusalem, 9190401, Israel
| | - Or Dishi
- Institute of Chemistry, The Center for Nanoscience and Nanotechnology, Casali Center for Applied Chemistry, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Jerusalem, 9190401, Israel
| | - Benny Bogoslavsky
- Institute of Chemistry, The Center for Nanoscience and Nanotechnology, Casali Center for Applied Chemistry, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Jerusalem, 9190401, Israel
| | - Ori Gidron
- Institute of Chemistry, The Center for Nanoscience and Nanotechnology, Casali Center for Applied Chemistry, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Jerusalem, 9190401, Israel.
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de Oteyza DG, Frederiksen T. Carbon-based nanostructures as a versatile platform for tunable π-magnetism. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2022; 34:443001. [PMID: 35977474 DOI: 10.1088/1361-648x/ac8a7f] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Accepted: 08/17/2022] [Indexed: 06/15/2023]
Abstract
Emergence ofπ-magnetism in open-shell nanographenes has been theoretically predicted decades ago but their experimental characterization was elusive due to the strong chemical reactivity that makes their synthesis and stabilization difficult. In recent years, on-surface synthesis under vacuum conditions has provided unprecedented opportunities for atomically precise engineering of nanographenes, which in combination with scanning probe techniques have led to a substantial progress in our capabilities to realize localized electron spin states and to control electron spin interactions at the atomic scale. Here we review the essential concepts and the remarkable advances in the last few years, and outline the versatility of carbon-basedπ-magnetic materials as an interesting platform for applications in spintronics and quantum technologies.
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Affiliation(s)
- Dimas G de Oteyza
- Nanomaterials and Nanotechnology Research Center (CINN), CSIC-UNIOVI-PA, E-33940 El Entrego, Spain
- Donostia International Physics Center (DIPC)-UPV/EHU, E-20018 San Sebastián, Spain
| | - Thomas Frederiksen
- Donostia International Physics Center (DIPC)-UPV/EHU, E-20018 San Sebastián, Spain
- Ikerbasque, Basque Foundation for Science, E-48013 Bilbao, Spain
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7
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A Special Issue in Honor of Professor Josef Michl. CHEMISTRY 2022. [DOI: 10.3390/chemistry4020021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
This Special Issue of Chemistry is dedicated to Professor Josef Michl [...]
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Pletzer M, Plasser F, Rimmele M, Heeney M, Glöcklhofer F. [2.2.2.2]Paracyclophanetetraenes (PCTs): cyclic structural analogues of poly( p‑phenylene vinylene)s (PPVs). OPEN RESEARCH EUROPE 2022; 1:111. [PMID: 37645175 PMCID: PMC10445936 DOI: 10.12688/openreseurope.13723.2] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 03/03/2022] [Indexed: 08/31/2023]
Abstract
Background: Poly( p-phenylene vinylene)s ( PPVs) and [2.2.2.2]paracyclophanetetraene ( PCT) are both composed of alternating π-conjugated para-phenylene and vinylene units. However, while the former constitute a class of π-conjugated polymers that has been used in organic electronics for decades, the latter is a macrocycle that only recently revealed its potential for applications such as organic battery electrodes. The cyclic structure endows PCT with unusual properties, and further tuning of these may be required for specific applications. Methods: In this article, we adopt an approach often used for tuning the properties of PPVs, the introduction of alkoxy (or alkylthio) substituents at the phenylene units, for tuning the optoelectronic properties of PCT. The resulting methoxy- and methylthio-substituted PCTs, obtained by Wittig cyclisation reactions, are studied by UV-vis absorption, photoluminescence, and cyclic voltammetry measurements, and investigated computationally using the visualisation of chemical shielding tensors (VIST) method. Results: The measurements show that substitution leads to slight changes in terms of absorption/emission energies and redox potentials while having a pronounced effect on the photoluminescence intensity. The computations show the effect of the substituents on the ring currents and chemical shielding and on the associated local and global (anti)aromaticity of the macrocycles, highlighting the interplay of local and global aromaticity in various electronic states. Conclusions: The study offers interesting insights into the tuneability of the properties of this versatile class of π-conjugated macrocycles.
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Affiliation(s)
- Matthias Pletzer
- Department of Chemistry, Imperial College London, London, W12 0BZ, UK
- Centre for Processable Electronics, Imperial College London, London, W12 0BZ, UK
| | - Felix Plasser
- Department of Chemistry, Loughborough University, Loughborough, LE11 3TU, UK
| | - Martina Rimmele
- Department of Chemistry, Imperial College London, London, W12 0BZ, UK
- Centre for Processable Electronics, Imperial College London, London, W12 0BZ, UK
| | - Martin Heeney
- Department of Chemistry, Imperial College London, London, W12 0BZ, UK
- Centre for Processable Electronics, Imperial College London, London, W12 0BZ, UK
| | - Florian Glöcklhofer
- Department of Chemistry, Imperial College London, London, W12 0BZ, UK
- Centre for Processable Electronics, Imperial College London, London, W12 0BZ, UK
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9
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Chen Y, Tseng SM, Chang KH, Chou PT. Energy Counterbalance to Harness Photoinduced Structural Planarization of Dibenzo[b,f]azepines toward Thermal Reversibility. J Am Chem Soc 2022; 144:1748-1757. [DOI: 10.1021/jacs.1c11231] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Yi Chen
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan, Republic of China
| | - Sheng-Ming Tseng
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan, Republic of China
| | - Kai-Hsin Chang
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan, Republic of China
| | - Pi-Tai Chou
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan, Republic of China
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10
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Lin L, Zhu J. Computational predictions of adaptive aromaticity for the design of singlet fission materials. Inorg Chem Front 2022. [DOI: 10.1039/d1qi01442k] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
The concept of adaptive aromaticity has been demonstrated as an alternative strategy for the design of singlet fission materials.
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Affiliation(s)
- Lu Lin
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, People's Republic of China
| | - Jun Zhu
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, People's Republic of China
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Baranac-Stojanović M, Stojanović M, Aleksić J. Revival of Hückel Aromatic (Poly)benzenoid Subunits in Triplet State Polycyclic Aromatic Hydrocarbons by Silicon Substitution. Chem Asian J 2021; 17:e202101261. [PMID: 34964285 DOI: 10.1002/asia.202101261] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 12/22/2021] [Indexed: 11/08/2022]
Abstract
By employing density functional theory (DFT) calculations we show that mono- and disilicon substitution in polycyclic aromatic hydrocarbons, having two to four benzene units, quenches their triplet state antiaromaticity by creating Hückel aromatic (poly)benzenoid subunit(s) and weakly antiaromatic, or almost nonaromatic silacycle. Therefore, such systems are predicted to be globally aromatic in both the ground state and the first excited triplet state. Putting the silicon atom(s) into various positions of a hydrocarbon provides an opportunity to tune the singlet-triplet energy gaps. They depend on the global aromaticity degree which, in turn, depends on the type of aromatic carbocyclic subunit(s) and the extent of their aromaticity. On the basis of the set of studied compounds, some preliminary rules on how to regulate the extent of global, semiglobal and local aromaticity are proposed. The results of this work extend the importance of Hückel aromaticity concept to excited triplet states which are usually characterized by the Baird type of (anti)aromaticity.
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Affiliation(s)
- Marija Baranac-Stojanović
- Faculty of Chemistry, University of Belgrade, Organic Chemistry, Studentski trg 16, 11000, Belgrade, SERBIA
| | - Milovan Stojanović
- Institute of Chemistry Technology and Metallurgy: Institut za hemiju tehnologiju i metalurgiju, Center for Chemistry, SERBIA
| | - Jovana Aleksić
- Institute of Chemistry Technology and Metallurgy: Institut za hemiju tehnologiju i metalurgiju, Center for Chemistry, SERBIA
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Feng R, Yu X, Autschbach J. Spin-Orbit Natural Transition Orbitals and Spin-Forbidden Transitions. J Chem Theory Comput 2021; 17:7531-7544. [PMID: 34792327 DOI: 10.1021/acs.jctc.1c00776] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Natural transition orbitals (NTOs) are in widespread use for visualizing and analyzing electronic transitions. The present work introduces the analysis of formally spin-forbidden transitions with the help of complex-valued spin-orbit (SO) NTOs. The analysis specifically focuses on the components in such transitions that cause their intensity to be nonzero because of SO coupling. Transition properties such as transition dipole moments are partitioned into SO-NTO hole-particle pairs, such that contributions to the intensity from specific occupied and unoccupied orbitals are obtained. The method has been implemented within the restricted active space (RAS) self-consistent field wave function theory framework, with SO coupling treated by RAS state interaction. SO-NTOs have a broad range of potential applications, which is illustrated by the T2-S1 state mixing in pyrazine, spin-forbidden versus spin-allowed 4f-5d transitions in the Tb3+ ion, and the phosphorescence of tris(2-phenylpyridine) iridium [Ir(ppy)3].
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Affiliation(s)
- Rulin Feng
- Department of Chemistry, University at Buffalo, State University of New York, Buffalo, New York 14260-3000, United States
| | - Xiaojuan Yu
- Department of Chemistry, University at Buffalo, State University of New York, Buffalo, New York 14260-3000, United States
| | - Jochen Autschbach
- Department of Chemistry, University at Buffalo, State University of New York, Buffalo, New York 14260-3000, United States
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Rimmele M, Nogala W, Seif-Eddine M, Roessler MM, Heeney M, Plasser F, Glöcklhofer F. Functional group introduction and aromatic unit variation in a set of π-conjugated macrocycles: revealing the central role of local and global aromaticity. Org Chem Front 2021; 8:4730-4745. [PMID: 34484800 PMCID: PMC8382046 DOI: 10.1039/d1qo00901j] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Accepted: 06/17/2021] [Indexed: 12/18/2022]
Abstract
π-Conjugated macrocycles are molecules with unique properties that are increasingly exploited for applications and the question of whether they can sustain global aromatic or antiaromatic ring currents is particularly intriguing. However, there are only a small number of experimental studies that investigate how the properties of π-conjugated macrocycles evolve with systematic structural changes. Here, we present such a systematic experimental study of a set of [2.2.2.2]cyclophanetetraenes, all with formally Hückel antiaromatic ground states, and combine it with an in-depth computational analysis. The study reveals the central role of local and global aromaticity for rationalizing the observed optoelectronic properties, ranging from extremely large Stokes shifts of up to 1.6 eV to reversible fourfold reduction, a highly useful feature for charge storage/accumulation applications. A recently developed method for the visualization of chemical shielding tensors (VIST) is applied to provide unique insight into local and global ring currents occurring in different planes along the macrocycle. Conformational changes as a result of the structural variations can further explain some of the observations. The study contributes to the development of structure-property relationships and molecular design guidelines and will help to understand, rationalize, and predict the properties of other π-conjugated macrocycles. It will also assist in the design of macrocycle-based supramolecular elements with defined properties.
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Affiliation(s)
- Martina Rimmele
- Department of Chemistry, Imperial College London London W12 0BZ UK .,Centre for Processable Electronics, Imperial College London London W12 0BZ UK
| | - Wojciech Nogala
- Institute of Physical Chemistry, Polish Academy of Sciences Kasprzaka 44/52 01-224 Warsaw Poland
| | | | - Maxie M Roessler
- Department of Chemistry, Imperial College London London W12 0BZ UK
| | - Martin Heeney
- Department of Chemistry, Imperial College London London W12 0BZ UK .,Centre for Processable Electronics, Imperial College London London W12 0BZ UK
| | - Felix Plasser
- Department of Chemistry, Loughborough University Loughborough LE11 3TU UK
| | - Florian Glöcklhofer
- Department of Chemistry, Imperial College London London W12 0BZ UK .,Centre for Processable Electronics, Imperial College London London W12 0BZ UK
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