1
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Escayola S, Labella J, Szczepanik DW, Poater A, Torres T, Solà M, Matito E. From (Sub)Porphyrins to (Sub)Phthalocyanines: Aromaticity Signatures in the UV-Vis Absorption Spectra. Inorg Chem 2024; 63:18251-18262. [PMID: 39297344 DOI: 10.1021/acs.inorgchem.4c03139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/01/2024]
Abstract
The development of novel synthetic methods has greatly expanded the toolbox available to chemists for engineering porphyrin and phthalocyanine derivatives with precise electronic and optical properties. In this study, we focus on the UV-vis absorption characteristics of substituted phthalocyanines and their contracted analogs, subphthalocyanines, which feature nonplanar, bowl-shaped geometries. These macrocycles, which are central to numerous applications in materials science and catalysis, possess extensive π-conjugated systems that drive their unique electronic properties. We explore how the change from a metalloid (B) to a metal (Zn) and the resulting coordination environments influence the aromaticity and, consequently, the spectroscopic features of these systems. A combined computational and experimental approach reveals a direct correlation between the aromaticity of the external conjugated pathways and the Q bands in the UV-vis spectra. Our findings highlight key structural modifications that can be leveraged to fine-tune the optical properties of porphyrinoid systems, offering new pathways for the design of advanced materials and catalysts with tailored functionalities.
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Affiliation(s)
- Sílvia Escayola
- Institut de Química Computacional i Catàlisi and Departament de Química, Universitat de Girona, C/Maria Aurèlia Capmany, 69, Girona, Catalonia 17003, Spain
- Donostia International Physics Center (DIPC), Donostia, Euskadi 20018, Spain
| | - Jorge Labella
- Departamento de Química Orgánica, Universidad Autónoma de Madrid, Madrid 28049, Spain
| | - Dariusz W Szczepanik
- Department of Theoretical Chemistry, Faculty of Chemistry, Jagiellonian University, Kraków 30-387, Poland
| | - Albert Poater
- Institut de Química Computacional i Catàlisi and Departament de Química, Universitat de Girona, C/Maria Aurèlia Capmany, 69, Girona, Catalonia 17003, Spain
| | - Tomas Torres
- Departamento de Química Orgánica, Universidad Autónoma de Madrid, Madrid 28049, Spain
- Institute for Advanced Research in Chemical Sciences (IAdChem), Universidad Autónoma de Madrid, Madrid 28049, Spain
- IMDEA-Nanociencia, Campus de Cantoblanco, Madrid 28049, Spain
| | - Miquel Solà
- Institut de Química Computacional i Catàlisi and Departament de Química, Universitat de Girona, C/Maria Aurèlia Capmany, 69, Girona, Catalonia 17003, Spain
| | - Eduard Matito
- Donostia International Physics Center (DIPC), Donostia, Euskadi 20018, Spain
- Ikerbasque Foundation for Science, Bilbao, Euskadi 48011, Spain
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2
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Ma Y, Feng X, Yu W, Shen C. Theoretical Study on Vibrationally Resolved Electronic Spectra of Chiral Nanographenes. Molecules 2024; 29:3999. [PMID: 39274847 PMCID: PMC11396777 DOI: 10.3390/molecules29173999] [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: 08/06/2024] [Revised: 08/19/2024] [Accepted: 08/22/2024] [Indexed: 09/16/2024] Open
Abstract
Nanographenes are of increasing importance owing to their potential applications in the photoelectronic field. Meanwhile, recent studies have primarily focused on the pure electronic spectra of nanographenes, which have been found to be inadequate for describing the experimental spectra that contain vibronic progressions. In this study, we focused on the vibronic effect on the electronic transition of a range of chiral nanographenes, especially in the low-energy regions with distinct vibronic progressions, using theoretical calculations. All the calculations were performed at the PBE0-D3(BJ)/def2-TZVP level of theory, adopting both time-dependent and time-independent approaches with Franck-Condon approximation. The resulting calculated curves exhibited good alignment with the experimental data. Notably, for the nanographenes incorporating helicene units, owing to the increasing π-extension, the major vibronic modes in the vibrationally resolved spectra differed significantly from those of the primitive helicenes. This investigation suggests that calculations that account for the vibronic effect could have better reproducibility compared with calculations based solely on pure electronic transitions. We anticipate that this study could pave the way for further investigations into optical and chiroptical properties, with a deeper understanding of the vibronic effect, thereby providing theoretical explanations with higher precision on more sophisticated nanographenes.
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Affiliation(s)
- Yijian Ma
- School of Chemistry and Chemical Engineering, Zhejiang Sci-Tech University, Hangzhou 310000, China
| | - Xian Feng
- School of Chemistry and Chemical Engineering, Zhejiang Sci-Tech University, Hangzhou 310000, China
| | - Wenxiong Yu
- School of Chemistry and Chemical Engineering, Zhejiang Sci-Tech University, Hangzhou 310000, China
| | - Chengshuo Shen
- School of Chemistry and Chemical Engineering, Zhejiang Sci-Tech University, Hangzhou 310000, China
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3
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Leyva-Parra L, Pino-Rios R, Inostroza D, Solà M, Alonso M, Tiznado W. Aromaticity and Magnetic Behavior in Benzenoids: Unraveling Ring Current Combinations. Chemistry 2024; 30:e202302415. [PMID: 37955853 DOI: 10.1002/chem.202302415] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Indexed: 11/14/2023]
Abstract
Nowadays, an active research topic is the connection between Clar's rule, aromaticity, and magnetic properties of polycyclic benzenoid hydrocarbons. In the present work, we employ a meticulous magnetically induced current density analysis to define the net current flowing through any cyclic circuit, connecting it to aromaticity based on the ring current concept. Our investigation reveals that the analyzed polycyclic systems display a prominent global ring current, contrasting with subdued semi-local and local ring currents. These patterns align with Clar's aromatic π-sextets only in cases where migrating π-sextet structures are invoked. The results of this study will enrich our comprehension of aromaticity and magnetic behavior in such systems, offering significant insights into coexisting ring current circuits in these systems.
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Affiliation(s)
- Luis Leyva-Parra
- Centro de Química Teórica & Computacional (CQT&C), Departamento de Ciencias Químicas, Facultad de Ciencias Exactas, Universidad Andrés Bello, Av. República 275, 8370146, Santiago, Chile
- Programa de Doctorado en Fisicoquímica Molecular, Facultad de Ciencias Exactas, Universidad Andrés Bello, Av. República 275, 8370146, Santiago, Chile
| | - Ricardo Pino-Rios
- Instituto de Estudios de la Salud, Universidad Arturo Prat, Iquique, 1100000, Chile
- Química y Farmacia, Facultad de Ciencias de la Salud, Universidad Arturo Prat, Casilla 121, Iquique, 1100000, Chile
| | - Diego Inostroza
- Centro de Química Teórica & Computacional (CQT&C), Departamento de Ciencias Químicas, Facultad de Ciencias Exactas, Universidad Andrés Bello, Av. República 275, 8370146, Santiago, Chile
- Programa de Doctorado en Fisicoquímica Molecular, Facultad de Ciencias Exactas, Universidad Andrés Bello, Av. República 275, 8370146, Santiago, Chile
| | - Miquel Solà
- Institute of Computational Chemistry and Catalysis, Departament of Chemistry, University of Girona, C/M Aurèlia Campmany 69, 17003, Girona, Catalonia, Spain
| | - Mercedes Alonso
- Departament of General Chemistry (ALGC), Vrije Universiteit Brussel, Pleinlaan 2, 1050, Brussels, Belgium
| | - William Tiznado
- Centro de Química Teórica & Computacional (CQT&C), Departamento de Ciencias Químicas, Facultad de Ciencias Exactas, Universidad Andrés Bello, Av. República 275, 8370146, Santiago, Chile
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4
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Yu X, Wu P, Yuan Q, Yan C, Li D, Cheng L. Unraveling the Aromatic Rule of Cyclic Superatomic Molecules in π-Conjugated Compounds. J Phys Chem A 2023; 127:7487-7495. [PMID: 37669444 DOI: 10.1021/acs.jpca.3c03872] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/07/2023]
Abstract
The aromaticity of π-conjugated compounds has long been a confusing issue. Based on a recently emerged two-dimensional (2D) superatomic-molecule theory, a unified rule was built to decipher the aromaticity of cyclic superatomic molecules of π-conjugated compounds from the chemical bonding perspective. Herein, a series of planar [n]helicenes and [n]circulenes, composed of benzene, thiophene, or furfuran, are systemically studied and seen as superatomic molecules ◊On-2◊F2 or ◊On, where superatoms ◊F and ◊O denote π-conjugated units with 5 and 4 π electrons, respectively. The ascertained superatomic Lewis structures intuitively display aromaticity with each basic unit meeting the superatomic sextet rule of benzene, similar to classical valence bond theory, which is favored by the synthesized complex π-conjugated compounds comprising different numbers and kinds of subrings. The evolutionary trend of ring currents and chemical bonding suggests a local ribbon-like aromaticity in these π-conjugated compounds. Moreover, nonplanar helical π-conjugated compounds have the potential to evolve into spring-like periodic materials with excellent physical properties.
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Affiliation(s)
- Xinlei Yu
- Department of Chemistry, Anhui University, Hefei 230601, China
| | - Panpan Wu
- Department of Chemistry, Anhui University, Hefei 230601, China
| | - Qinqin Yuan
- Department of Chemistry, Anhui University, Hefei 230601, China
| | - Chen Yan
- Department of Chemistry, Anhui University, Hefei 230601, China
| | - Dan Li
- Department of Chemistry, Anhui University, Hefei 230601, China
| | - Longjiu Cheng
- Department of Chemistry, Anhui University, Hefei 230601, China
- Key Laboratory of Functional Inorganic Materials of Anhui Province, Anhui Province Key Laboratory of Chemistry for Inorganic/Organic Hybrid Functionalized Materials, Key Laboratory of Structure and Functional Regulation of Hybrid Materials (Anhui University), Ministry of Education, Hefei 230601, China
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5
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Macleod-Carey D, Muñoz-Castro A. Switch from local to global aromatic character in Möbius carbon nanobelts upon dioxidation. Evaluation of magnetic behavior in neutral and charged species. Phys Chem Chem Phys 2023; 25:4467-4471. [PMID: 36722854 DOI: 10.1039/d2cp05326h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Here we show that recent Möbius carbon nanobelts (MCNBs) can be switched from a local to a global aromatic behavior upon dioxidation. Hence, large aromatic structures can be achieved by the choice of the charge states, giving rise to shielding cone characteristics extended within the overall structure at the nanoscale regime, pushing the limit of aromatic circuits to 198 π-electrons.
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Affiliation(s)
- Desmond Macleod-Carey
- Laboratorio de Química Inorgánica y Materiales Moleculares, Facultad de Ingenieria, Universidad Autonoma de Chile, Llano Subercaceaux 2801, San Miguel, Santiago, Chile
| | - Alvaro Muñoz-Castro
- Facultad de Ingeniería, Arquitectura y Diseño, Universidad San Sebastián, Bellavista 7, Santiago, 8420524, Chile.
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6
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Pedersen VBR, Pedersen SK, Jin Z, Kofod N, Laursen BW, Baryshnikov GV, Nuckolls C, Pittelkow M. Electronic Materials: An Antiaromatic Propeller Made from the Four-Fold Fusion of Tetraoxa[8]circulene and Perylene Diimides. Angew Chem Int Ed Engl 2022; 61:e202212293. [PMID: 36173989 PMCID: PMC9828547 DOI: 10.1002/anie.202212293] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2022] [Indexed: 01/12/2023]
Abstract
The synthesis of an antiaromatic tetraoxa[8]circulene annulated with four perylene diimides (PDI), giving a dynamic non-planar π-conjugated system, is described. The molecule contains 32 aromatic rings surrounding one formally antiaromatic planarized cyclooctatetraene (COT). The intense absorption (ϵ=3.35×105 M-1 cm-1 in CH2 Cl2 ) and emission bands are assigned to internal charge-transfer transitions in the combined PDI-circulene π-system. The spectroscopic data is supported by density functional theory calculations, and nuclear independent chemical shift calculation indicate that the antiaromatic COT has increased aromaticity in the reduced state. Electrochemical studies show that the compound can reversibly reach the tetra- and octa-anionic states by reduction of the four PDI units, and the deca-anionic state by reduction of the central COT ring. The material functions effectively in bulk hetero junction solar cells as a non-fullerene acceptor, reaching a power conversion efficiency of 6.4 %.
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Affiliation(s)
- Viktor B. R. Pedersen
- Department of ChemistryUniversity of CopenhagenUniversitetsparken 52100Copenhagen ØDenmark
| | - Stephan K. Pedersen
- Department of ChemistryUniversity of CopenhagenUniversitetsparken 52100Copenhagen ØDenmark
| | - Zexin Jin
- Department of ChemistryColumbia University3000 BroadwayNew YorkNYUSA
| | - Nicolaj Kofod
- Department of ChemistryUniversity of CopenhagenUniversitetsparken 52100Copenhagen ØDenmark
| | - Bo W. Laursen
- Department of ChemistryUniversity of CopenhagenUniversitetsparken 52100Copenhagen ØDenmark
| | - Glib V. Baryshnikov
- Department of Science and TechnologyLaboratory of Organic ElectronicsLinköping UniversityNorrköpingSE-60174Sweden
| | - Colin Nuckolls
- Department of ChemistryColumbia University3000 BroadwayNew YorkNYUSA
| | - Michael Pittelkow
- Department of ChemistryUniversity of CopenhagenUniversitetsparken 52100Copenhagen ØDenmark
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7
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8
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Stasyuk OA, Stasyuk AJ, Solà M, Voityuk AA. Nitrogen-doped molecular bowls as electron donors in photoinduced electron transfer reactions. NANOSCALE ADVANCES 2022; 4:2180-2188. [PMID: 36133447 PMCID: PMC9418722 DOI: 10.1039/d2na00150k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Accepted: 03/27/2022] [Indexed: 06/16/2023]
Abstract
In recent years, the chemistry of curved π-conjugated molecules has experienced a sharp rise. The inclusion of a heteroatom in the carbon network significantly affects its semiconducting properties. In this work, we computationally study the photoinduced electron transfer in a series of C60 fullerene complexes with experimentally established nitrogen-doped molecular bowls. Our results demonstrate that introducing nitrogen into pentagonal rings of the bowl-shaped π-conjugated molecules and extending the π-conjugation can modulate their electron-transfer properties. Among the studied complexes, the hub-NCor⊃C60 complex exhibits the most desirable combination of ultrafast charge separation and slow charge recombination, suggesting its potential use in photovoltaics.
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Affiliation(s)
- O A Stasyuk
- Institut de Química Computacional, Departament de Química, Universitat de Girona C/ Maria Aurèlia Capmany 69 17003 Girona Spain
- Faculty of Chemistry, University of Warsaw Pasteura 1 02-093 Warsaw Poland
| | - A J Stasyuk
- Institut de Química Computacional, Departament de Química, Universitat de Girona C/ Maria Aurèlia Capmany 69 17003 Girona Spain
- Faculty of Chemistry, University of Warsaw Pasteura 1 02-093 Warsaw Poland
| | - M Solà
- Institut de Química Computacional, Departament de Química, Universitat de Girona C/ Maria Aurèlia Capmany 69 17003 Girona Spain
| | - A A Voityuk
- Institut de Química Computacional, Departament de Química, Universitat de Girona C/ Maria Aurèlia Capmany 69 17003 Girona Spain
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9
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Zank S, Fernández‐García JM, Stasyuk AJ, Voityuk AA, Krug M, Solà M, Guldi DM, Martín N. Initiating Electron Transfer in Doubly Curved Nanographene Upon Supramolecular Complexation of C 60. Angew Chem Int Ed Engl 2022; 61:e202112834. [PMID: 34633126 PMCID: PMC9303211 DOI: 10.1002/anie.202112834] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Indexed: 11/25/2022]
Abstract
The formation of supramolecular complexes between C60 and a molecular nanographene endowed with both positive and negative curvatures is described. The presence of a corannulene moiety and the saddle shape of the molecular nanographene allows the formation of complexes with 1:1, 1:2, and 2:1 stoichiometries. The association constants for the three possible supramolecular complexes were determined by 1 H NMR titration. Furthermore, the stability of the three complexes was calculated by theoretical methods that also predict the photoinduced electron transfer from the curved nanographene to the electron acceptor C60 . Time-resolved transient absorption measurements on the ns-time scale showed that the addition of C60 to NG-1 solutions and photo-exciting them at 460 nm leads to the solvent-dependent formation of new species, in particular the formation of the one-electron reduced form of C60 in benzonitrile was observed.
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Affiliation(s)
- Simon Zank
- Department of Chemistry and PharmacyFriedrich-Alexander-UniversitätEgerlandstrasse 391058ErlangenGermany
| | - Jesús M. Fernández‐García
- Departamento de Química Orgánica IFacultad de Ciencias QuímicasUniversidad Complutense de MadridAvd. de la Complutense, S/N28040MadridSpain
| | - Anton J. Stasyuk
- Institut de Química Computacional and Departament de QuímicaUniversitat de GironaC/ Maria Aurèlia Capmany 6917003GironaSpain
| | - Alexander A. Voityuk
- Institut de Química Computacional and Departament de QuímicaUniversitat de GironaC/ Maria Aurèlia Capmany 6917003GironaSpain
- Institució Catalana de Recerca i Estudis Avancats (ICREA)08010BarcelonaSpain
| | - Marcel Krug
- Department of Chemistry and PharmacyFriedrich-Alexander-UniversitätEgerlandstrasse 391058ErlangenGermany
| | - Miquel Solà
- Institut de Química Computacional and Departament de QuímicaUniversitat de GironaC/ Maria Aurèlia Capmany 6917003GironaSpain
| | - Dirk M. Guldi
- Department of Chemistry and PharmacyFriedrich-Alexander-UniversitätEgerlandstrasse 391058ErlangenGermany
| | - Nazario Martín
- Departamento de Química Orgánica IFacultad de Ciencias QuímicasUniversidad Complutense de MadridAvd. de la Complutense, S/N28040MadridSpain
- IMDEA-NanocienciaC/ Faraday, 9, Campus de Cantoblanco28049MadridSpain
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10
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Zank S, Fernández‐García JM, Stasyuk AJ, Voityuk AA, Krug M, Solà M, Guldi DM, Martín N. Initiating Electron Transfer in Doubly Curved Nanographene Upon Supramolecular Complexation of C
60. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202112834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Simon Zank
- Department of Chemistry and Pharmacy Friedrich-Alexander-Universität Egerlandstrasse 3 91058 Erlangen Germany
| | - Jesús M. Fernández‐García
- Departamento de Química Orgánica I Facultad de Ciencias Químicas Universidad Complutense de Madrid Avd. de la Complutense, S/N 28040 Madrid Spain
| | - Anton J. Stasyuk
- Institut de Química Computacional and Departament de Química Universitat de Girona C/ Maria Aurèlia Capmany 69 17003 Girona Spain
| | - Alexander A. Voityuk
- Institut de Química Computacional and Departament de Química Universitat de Girona C/ Maria Aurèlia Capmany 69 17003 Girona Spain
- Institució Catalana de Recerca i Estudis Avancats (ICREA) 08010 Barcelona Spain
| | - Marcel Krug
- Department of Chemistry and Pharmacy Friedrich-Alexander-Universität Egerlandstrasse 3 91058 Erlangen Germany
| | - Miquel Solà
- Institut de Química Computacional and Departament de Química Universitat de Girona C/ Maria Aurèlia Capmany 69 17003 Girona Spain
| | - Dirk M. Guldi
- Department of Chemistry and Pharmacy Friedrich-Alexander-Universität Egerlandstrasse 3 91058 Erlangen Germany
| | - Nazario Martín
- Departamento de Química Orgánica I Facultad de Ciencias Químicas Universidad Complutense de Madrid Avd. de la Complutense, S/N 28040 Madrid Spain
- IMDEA-Nanociencia C/ Faraday, 9, Campus de Cantoblanco 28049 Madrid Spain
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11
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Poater J, Heitkämper J, Poater A, Maraval V, Chauvin R. Zwitterionic Aromaticity on Azulene Extrapolated to
carbo
‐Azulene. European J Org Chem 2021. [DOI: 10.1002/ejoc.202101228] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Jordi Poater
- Departament de Química Inorgànica i Orgànica & IQTCUB Universitat de Barcelona 08028 Barcelona Spain
- ICREA 08010 Barcelona Spain
| | - Juliane Heitkämper
- Universität Stuttgart Institut für Theoretische Chemie Pfaffenwaldring 55 70569 Stuttgart Germany
- Institut de Química Computacional i Catàlisi and Departament de Química Universitat de Girona, c/ Mª Aurèlia Capmany 69 17003 Girona, Catalonia Spain
| | - Albert Poater
- Institut de Química Computacional i Catàlisi and Departament de Química Universitat de Girona, c/ Mª Aurèlia Capmany 69 17003 Girona, Catalonia Spain
| | - Valérie Maraval
- LCC-CNRS University of Toulouse 205 route de Narbonne 31077 Toulouse France
| | - Remi Chauvin
- LCC-CNRS University of Toulouse 205 route de Narbonne 31077 Toulouse France
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12
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Mauksch M, Tsogoeva SB. Disclosure of Ground-State Zimmerman-Möbius Aromaticity in the Radical Anion of [6]Helicene and Evidence for 4π Periodic Aromatic Ring Currents in a Molecular "Metallic" Möbius Strip. Chemistry 2021; 27:14660-14671. [PMID: 34375466 PMCID: PMC8596793 DOI: 10.1002/chem.202102230] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Indexed: 12/19/2022]
Abstract
In 1966, Zimmerman proposed a type of Möbius aromaticity that involves through-space electron delocalization; it has since been widely applied to explain reactivity in pericyclic reactions, but is considered to be limited to transition-state structures. Although the easily accessible hexahelicene radical anion has been known for more than half a century, it was overlooked that it exhibits a ground-state minimum and robust Zimmerman-Möbius aromaticity in its central noose-like opening, becoming, hence, the oldest existing Möbius aromatic system and with smallest Möbius cycle known. Despite its overall aromatic stabilization energy of 13.6 kcal mol-1 (at B3LYP/6-311+G**), the radical also features a strong, globally induced paramagnetic ring current along its outer edge. Exclusive global paramagnetic currents can also be found in other fully delocalized radical anions of 4N+2 π-electron aromatic polycyclic benzenoid hydrocarbons (PAH), thus questioning the established magnetic criterion of antiaromaticity. As an example of a PAH with nontrivial topology, we studied a novel Möbius[16]cyclacene that has a non-orientable surface manifold and a stable closed-shell singlet ground state at several density functional theory levels. Its metallic monoanion radical (0.0095 eV band gap at HSE06/6-31G* level) is also wave-function stable and displays an unusual 4π-periodic, magnetically induced ring current (reminiscent of the transformation behaviour of spinors under spatial rotation), thus indicating the existence of a new, Hückel-rule-evading type of aromaticity.
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Affiliation(s)
- Michael Mauksch
- Department of Chemistry and PharmacyInstitute of Theoretical ChemistryComputer Chemistry CenterFriedrich-Alexander-Universität Erlangen-Nürnberg (FAU)Nägelsbachstrasse 25a91052ErlangenGermany
| | - Svetlana B. Tsogoeva
- Department of Chemistry and PharmacyOrganic Chemistry Chair I andInterdisciplinary Center for Molecular Materials (ICMM)Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU)Nikolaus-Fiebinger Str. 1091058ErlangenGermany
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13
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Artigas A, Hagebaum-Reignier D, Carissan Y, Coquerel Y. Visualizing electron delocalization in contorted polycyclic aromatic hydrocarbons. Chem Sci 2021; 12:13092-13100. [PMID: 34745540 PMCID: PMC8513938 DOI: 10.1039/d1sc03368a] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Accepted: 09/03/2021] [Indexed: 11/21/2022] Open
Abstract
Electron delocalization in contorted polycyclic aromatic hydrocarbon (PAH) molecules was examined through 3D isotropic magnetic shielding (IMS) contour maps built around the molecules using pseudo-van der Waals surfaces. The resulting maps of electron delocalization provided an intuitive, yet detailed and quantitative evaluation of the aromatic, non aromatic, and antiaromatic character of the local and global conjugated cyclic circuits distributed over the molecules. An attractive pictural feature of the 3D IMS contour maps is that they are reminiscent of the Clar π-sextet model of aromaticity. The difference in delocalization patterns between the two faces of the electron circuits in contorted PAHs was clearly visualized. For π-extended contorted PAHs, some splits of the π system resulted in recognizable patterns typical of smaller PAHs. The differences between the delocalization patterns of diastereomeric chiral PAHs could also be visualized. Mapping IMS on pseudo-van der Waals surfaces around contorted PAHs allowed visualization of their superimposed preferred circuits for electron delocalization and hence their local and global aromaticity patterns.
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Affiliation(s)
- Albert Artigas
- Aix Marseille Université, CNRS, Centrale Marseille, ISM2 13397 Marseille France
| | | | - Yannick Carissan
- Aix Marseille Université, CNRS, Centrale Marseille, ISM2 13397 Marseille France
| | - Yoann Coquerel
- Aix Marseille Université, CNRS, Centrale Marseille, ISM2 13397 Marseille France
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14
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Escayola S, Poater J, Ramos M, Luque‐Urrutia JA, Duran J, Simon S, Solà M, Cavallo L, Nolan SP, Poater A. Chelation enforcing a dual gold configuration in the catalytic hydroxyphenoxylation of alkynes. Appl Organomet Chem 2021. [DOI: 10.1002/aoc.6362] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Sílvia Escayola
- Institut de Química Computacional i Catàlisi, Departament de Química Universitat de Girona Girona Spain
| | - Jordi Poater
- Departament de Química Inorgànica i Orgànica and IQTCUB Universitat de Barcelona Barcelona Spain
- ICREA Barcelona Spain
| | - Miguel Ramos
- Institut de Química Computacional i Catàlisi, Departament de Química Universitat de Girona Girona Spain
| | | | - Josep Duran
- Institut de Química Computacional i Catàlisi, Departament de Química Universitat de Girona Girona Spain
| | - Sílvia Simon
- Institut de Química Computacional i Catàlisi, Departament de Química Universitat de Girona Girona Spain
| | - Miquel Solà
- Institut de Química Computacional i Catàlisi, Departament de Química Universitat de Girona Girona Spain
| | - Luigi Cavallo
- KAUST Catalysis Center (KCC) King Abdullah University of Science and Technology Thuwal Saudi Arabia
| | - Steven P. Nolan
- Department of Chemistry and Center for Sustainable Chemistry Ghent University Ghent Belgium
| | - Albert Poater
- Institut de Química Computacional i Catàlisi, Departament de Química Universitat de Girona Girona Spain
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15
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Muñoz-Castro A. Aromaticity in Phenyl Decorated closo-Monocarboranes. Planar-Spherical Aggregates Involving 7-12-Vertex Cages. J Phys Chem A 2021; 125:4861-4866. [PMID: 34048262 DOI: 10.1021/acs.jpca.1c02934] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The characterized phenyl decorated closo-monocarboranes with variable sizes from 7- to 12-vertex cages, [Ph-closo-CBnHn]-, n = 6-11, allow us to address the role of the varying size and shape of the carborane cage in dual planar-spherical aromatic species. Our results show the formation of adjacent shielding cone characteristics enabled from both planar and spherical aromatic fragments, despite the different structures of the closo-monocarboranes. Under a field perpendicular to the phenyl ring, both shielding cones are enabled, which overlap at long-range regions, in contrast to other orientations leading to a short-range response from the planar aromatic fragment. Thus, a two- or one-aromatic circuit is enabled selectively within the same molecular unit, by controlling the orientation of the external field. Along with the series, a variable extension of the shielding cone from the carborane cage is observed, which is larger for the -CB11H11 case, decreasing toward -CB6H6, denoting a similar extension from both the planar and spherical aromatic regions at the [4-Ph-closo-4-CB8H8]- (4) counterpart. The analysis of such multiple aromatic structures shows that, despite the different sizes and shapes of the closo cages, a similar aromatic behavior remains. In addition, the anisotropy of the induced magnetic field is given graphically, denoting a larger anisotropy for the planar aromatic moiety owing to its two-dimensional structure, which is suggested to discriminate between planar and spherical aromatic fragments within the same molecule.
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Affiliation(s)
- Alvaro Muñoz-Castro
- Grupo de Química Inorgánica y Materiales Moleculares, Facultad de Ingeniería, Universidad Autonoma de Chile, El Llano Subercaseaux 2801 Santiago, Chile
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