1
|
Song Y, Zhu J. Spin population determines whether antiaromaticity can increase or decrease radical stability. Phys Chem Chem Phys 2024; 26:21213-21221. [PMID: 39073087 DOI: 10.1039/d4cp01031k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/30/2024]
Abstract
Aromaticity, as a classical and fundamental concept in chemistry, can enhance thermodynamic stability. In sharp contrast, a previous study showed that antiaromaticity rather than aromaticity can enhance the radical stability of α-methyl heterocyclic compounds. Here, we demonstrate a similar antiaromaticity-promoted radical stability when the methyl group is replaced by five-membered (alkyl)(amino)cyclics (AACs). More interestingly, when an AAC is fused with an antiaromatic ring, the radical stability could be either reduced or enhanced, depending on the spin population. Specifically, when the spin density is populated on an incoming antiaromatic 1,4-dihydro-1,4-diborinine moiety, the radical stability is enhanced whereas when the spin density is maintained on the original five-membered ring, the radical stability is reduced. Our findings highlight the importance of spin density in tuning the radical stability, inviting experimental chemists' verification.
Collapse
Affiliation(s)
- Yanlin Song
- 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
- School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, 518172, People's Republic of China.
| |
Collapse
|
2
|
Sidler E, Hein R, Doellerer D, Feringa BL. Redox-Switchable Aromaticity in a Helically Extended Indeno[2,1- c]fluorene. J Am Chem Soc 2024; 146:19168-19176. [PMID: 38954739 PMCID: PMC11258684 DOI: 10.1021/jacs.4c04191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2024] [Revised: 06/19/2024] [Accepted: 06/20/2024] [Indexed: 07/04/2024]
Abstract
Molecular switches have received major attention to enable the reversible modulation of various molecular properties and have been extensively used as trigger elements in diverse fields, including molecular machines, responsive materials, and photopharmacology. Antiaromaticity is a fascinating property that has attracted not only significant fundamental interest but is also increasingly relevant in different applications, in particular organic (opto)electronics. However, designing systems in which (anti)aromaticity can be judiciously and reversibly switched ON and OFF remains challenging. Herein, we report a helicene featuring an indenofluorene-bridged bisthioxanthylidene as a novel switch wherein a simultaneous two-electron (electro)chemical redox process allows highly reversible modulation of its (anti)aromatic character. Specifically, the two thioxanthylidene rotors, attached to the initially aromatic indenofluorene scaffold via overcrowded alkenes, adopt an anti-folded structure, which upon oxidation convert to singly bonded, twisted conformations. This is not only associated with significant (chir)optical changes but importantly also results in formation of the fully conjugated, formally antiaromatic as-indacene motif in the helical core of the switch. This process proceeds without the buildup of radical cation intermediates and thus enables highly reversible switching of molecular geometry, aromaticity, absorbance, and chiral expression under ambient conditions, as evidenced by NMR, UV-vis, CD, and (spectro)electrochemical analyses, supported by DFT calculations. We expect this concept to be extendable to a wide range of robust antiaromatic-aromatic switches and to provide a basis for modulation of the structure and properties of these fascinating inherently chiral polycyclic π-scaffolds.
Collapse
Affiliation(s)
| | | | - Daniel Doellerer
- Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747
AG Groningen, The
Netherlands
| | - Ben L. Feringa
- Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747
AG Groningen, The
Netherlands
| |
Collapse
|
3
|
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.
Collapse
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
| |
Collapse
|
4
|
Nikulshin PV, Makarov AY, Koskin IP, Becker CS, Kazantsev MS, Beckmann J, Balmohammadi Y, Grabowsky S, Mebs S, Naumova OV, Protasov DY, Svit KA, Irtegova IG, Radiush EA, Bagryanskaya IY, Shundrin LA, Zibarev AV. 1,2,3,4-Tetrafluorobiphenylene: A Prototype Janus-Headed Scaffold for Ambipolar Materials. Chempluschem 2024; 89:e202300692. [PMID: 38052725 DOI: 10.1002/cplu.202300692] [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: 11/26/2023] [Revised: 12/01/2023] [Accepted: 12/05/2023] [Indexed: 12/07/2023]
Abstract
The title compound was synthesized by Ullmann cross-coupling in low yield as the first representative of [n]phenylene containing hydrocarbon and fluorocarbon rings. Stille/Suzuki-Miyaura cross-coupling reactions, as well as substitution of fluorine in suitable starting compounds, failed to give the same product. The geometric and electronic structures of the title compound were studied by X-ray diffraction, cyclic voltammetry and density functional theory calculations, together with Hirshfeld surface and reduced density gradient analyses. The crystal structure features head-to-tail π-stacking and other fluorine-related secondary bonding interactions. From the nucleus-independent chemical shifts descriptor, the four-membered ring of the title compound is antiaromatic, and the six-membered rings are aromatic. The Janus molecule is highly polarized; and the six-membered fluoro- and hydrocarbon rings are Lewis π-acidic and π-basic, respectively. The electrochemically-generated radical cation of the title compound is long-lived as characterized by electron paramagnetic resonance, whereas the radical anion is unstable in solution. The title compound reveals electrical properties of an insulator. On expanding its molecular scaffold towards partially fluorinated [n]phenylenes (n≥2), the properties presumably can be transformed into those of semiconductors. In this context, the title compound is suggested as a prototype scaffold for ambipolar materials for organic electronics and spintronics.
Collapse
Affiliation(s)
- Pavel V Nikulshin
- Vorozhtsov Novosibirsk Institute of Organic Chemistry, Siberian Branch of the Russian Academy of Sciences, 630090, Novosibirsk, Russia
- Current address: Topchiev Institute of Petrochemical Synthesis, Russian Academy of Sciences, 119991, Moscow, Russia
| | - Alexander Yu Makarov
- Vorozhtsov Novosibirsk Institute of Organic Chemistry, Siberian Branch of the Russian Academy of Sciences, 630090, Novosibirsk, Russia
| | - Igor P Koskin
- Vorozhtsov Novosibirsk Institute of Organic Chemistry, Siberian Branch of the Russian Academy of Sciences, 630090, Novosibirsk, Russia
| | - Christina S Becker
- Vorozhtsov Novosibirsk Institute of Organic Chemistry, Siberian Branch of the Russian Academy of Sciences, 630090, Novosibirsk, Russia
| | - Maxim S Kazantsev
- Vorozhtsov Novosibirsk Institute of Organic Chemistry, Siberian Branch of the Russian Academy of Sciences, 630090, Novosibirsk, Russia
| | - Jens Beckmann
- Institute for Inorganic Chemistry and Crystallography, University of Bremen, 28359, Bremen, Germany
| | - Yaser Balmohammadi
- Department of Chemistry, Biochemistry and Pharmaceutical Science, University of Bern, 3012, Bern, Switzerland
| | - Simon Grabowsky
- Department of Chemistry, Biochemistry and Pharmaceutical Science, University of Bern, 3012, Bern, Switzerland
| | - Stefan Mebs
- Institute for Experimental Physics, Free University of Berlin, 14195, Berlin, Germany
| | - Olga V Naumova
- Rzhanov Institute of Semiconductor Physics, Siberian Branch of the Russian Academy of Sciences, 630090, Novosibirsk, Russia
| | - Dmitry Yu Protasov
- Rzhanov Institute of Semiconductor Physics, Siberian Branch of the Russian Academy of Sciences, 630090, Novosibirsk, Russia
| | - Kirill A Svit
- Rzhanov Institute of Semiconductor Physics, Siberian Branch of the Russian Academy of Sciences, 630090, Novosibirsk, Russia
| | - Irina G Irtegova
- Vorozhtsov Novosibirsk Institute of Organic Chemistry, Siberian Branch of the Russian Academy of Sciences, 630090, Novosibirsk, Russia
| | - Ekaterina A Radiush
- Vorozhtsov Novosibirsk Institute of Organic Chemistry, Siberian Branch of the Russian Academy of Sciences, 630090, Novosibirsk, Russia
| | - Irina Yu Bagryanskaya
- Vorozhtsov Novosibirsk Institute of Organic Chemistry, Siberian Branch of the Russian Academy of Sciences, 630090, Novosibirsk, Russia
| | - Leonid A Shundrin
- Vorozhtsov Novosibirsk Institute of Organic Chemistry, Siberian Branch of the Russian Academy of Sciences, 630090, Novosibirsk, Russia
| | - Andrey V Zibarev
- Vorozhtsov Novosibirsk Institute of Organic Chemistry, Siberian Branch of the Russian Academy of Sciences, 630090, Novosibirsk, Russia
| |
Collapse
|
5
|
Kalapos P, Kunfi A, Bogner MM, Holczbauer T, Kochman MA, Durbeej B, London G. Salicylideneaniline/Dithienylethene Hybrid Molecular Switches: Design, Synthesis, and Photochromism. J Org Chem 2024; 89:16-26. [PMID: 38060251 PMCID: PMC10777402 DOI: 10.1021/acs.joc.3c00828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Revised: 11/16/2023] [Accepted: 11/27/2023] [Indexed: 12/08/2023]
Abstract
A hybrid molecular switch comprising salicylideneaniline (SA) and dithienylethene (DTE) moieties around a single benzene ring is reported. Due to an interplay between solvent-assisted enol-keto tautomerization in the former moiety and photochromic electrocyclization in the latter, this dithienylbenzene derivative was found to be photoresponsive at room temperature with a thermally stable closed form. The main photoproduct featuring ring-closed DTE and keto-enamine SA structures could be isolated and converted back to the starting material by irradiation with visible light. The optical properties of the potential structures involved in the overall process were characterized by using density functional theory (DFT) calculations in good agreement with the measured data. The reversibility of the conversion could be tuned by the presence of donor and acceptor substituents, while the introduction of the imine in the form of a benzothiazole moiety enabled photochemistry even in nonprotic solvents.
Collapse
Affiliation(s)
- Péter
Pál Kalapos
- MTA
TTK Lendület Functional Organic Materials Research Group, Institute of Organic Chemistry, Research Centre for
Natural Sciences, Magyar
Tudósok Krt. 2, 1117 Budapest, Hungary
| | - Attila Kunfi
- MTA
TTK Lendület Functional Organic Materials Research Group, Institute of Organic Chemistry, Research Centre for
Natural Sciences, Magyar
Tudósok Krt. 2, 1117 Budapest, Hungary
| | - Marcell M. Bogner
- MTA
TTK Lendület Functional Organic Materials Research Group, Institute of Organic Chemistry, Research Centre for
Natural Sciences, Magyar
Tudósok Krt. 2, 1117 Budapest, Hungary
| | - Tamás Holczbauer
- Institute
of Organic Chemistry, Centre for Structural
Science, Research Centre for Natural Sciences, Magyar Tudósok Krt. 2, 1117 Budapest, Hungary
| | - Michał Andrzej Kochman
- Institute
of Physical Chemistry, Polish Academy of
Sciences, Marcina Kasprzaka
44/52, 01-224 Warsaw, Poland
| | - Bo Durbeej
- Division
of Theoretical Chemistry, IFM, Linköping
University, SE-58183 Linköping, Sweden
| | - Gábor London
- MTA
TTK Lendület Functional Organic Materials Research Group, Institute of Organic Chemistry, Research Centre for
Natural Sciences, Magyar
Tudósok Krt. 2, 1117 Budapest, Hungary
| |
Collapse
|
6
|
Li R, Fang Q, Chen M, Yamada M, Tsuji Y, Kugai Y, Li W, Kawai T. Synthesis and Photochromic Properties of Diaryl [5]Helicene Derivatives. Chemistry 2023; 29:e202302693. [PMID: 37749870 DOI: 10.1002/chem.202302693] [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: 08/17/2023] [Revised: 09/23/2023] [Accepted: 09/25/2023] [Indexed: 09/27/2023]
Abstract
Photoinduced tuning of aromaticity and correlative molecular properties has attracted enormous interest in recent years both for modulating photochromism properties and designing novel photochromic materials. Here, we report the synthesis and photochemical characterization of diaryl[5]helicene-based diarylethene molecular switches. 3,4-Bis(2,4-dimethyl-5-phenylthiophen-3-yl)dibenzo[c,g]phenanthrene derivative 1 a showed no photochromic reaction, whereas 3,4-bis(2-methyl-5-phenylthiophen-3-yl)dibenzo[c,g]phenanthrene derivative 2 a and 3,4-bis(5-methyl-2-phenylthiazol-4-yl)dibenzo[c,g]phenanthrene derivative 3 a exhibited reversible photochromism in different aprotic solvents with specific light irradiation. Meanwhile, the diarylethene compounds 2 a and 3 a underwent turn-off mode fluorescence photoswitching together with photoisomerization upon light irradiation. Remarkably, the photoinduced changes in the aromaticity of [5]helicene as a central ethene bridge along with the relative smaller activation energy and higher frequency factor facilitated the thermal bleaching rates of diarylethene switches 2 and 3 in solution. This research provides new insight for designing aromatic diarylethene photoswitches for reversible fluorescence switching, photoinduced changes in aromaticity and further fast thermal back reactions.
Collapse
Affiliation(s)
- Ruiji Li
- School of Pharmacy, Jining Medical University, Rizhao, Shandong, 276826, P. R. China
- Division of Materials Science, Nara Institute of Science and Technology (NAIST), Ikoma, Nara, 630-0192, Japan
| | - Qi Fang
- School of Pharmacy, Jining Medical University, Rizhao, Shandong, 276826, P. R. China
| | - Minghui Chen
- School of Pharmacy, Jining Medical University, Rizhao, Shandong, 276826, P. R. China
| | - Mihoko Yamada
- Division of Materials Science, Nara Institute of Science and Technology (NAIST), Ikoma, Nara, 630-0192, Japan
| | - Yugo Tsuji
- Division of Materials Science, Nara Institute of Science and Technology (NAIST), Ikoma, Nara, 630-0192, Japan
| | - Yusuke Kugai
- Division of Materials Science, Nara Institute of Science and Technology (NAIST), Ikoma, Nara, 630-0192, Japan
| | - Wei Li
- School of Pharmacy, Jining Medical University, Rizhao, Shandong, 276826, P. R. China
| | - Tsuyoshi Kawai
- Division of Materials Science, Nara Institute of Science and Technology (NAIST), Ikoma, Nara, 630-0192, Japan
| |
Collapse
|
7
|
Lvov AG, Koffi Kouame E, Khusniyarov MM. Light-Induced Dyotropic Rearrangement of Diarylethenes: Scope, Mechanism, and Prospects. Chemistry 2023; 29:e202301480. [PMID: 37477021 DOI: 10.1002/chem.202301480] [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: 05/10/2023] [Revised: 07/14/2023] [Accepted: 07/19/2023] [Indexed: 07/22/2023]
Abstract
Irreversible two-photon photorearrangement of 1,2-diarylethenes is a unique process providing access to complex 2a1 ,5a-dihydro-5,6-dithiaacenaphthylene (DDA) heterocyclic core. This reaction was serendipitously discovered during studies on photoswitchable diarylethenes and was initially considered as a highly undesired process. However, in recent years, it has been recognized as an efficient photochemical reaction, interesting by itself and as a promising synthetic method for the synthesis of challenging molecules. Herein, we discuss the state-of-the-art in studies on this notable process.
Collapse
Affiliation(s)
- Andrey G Lvov
- Irkutsk National Research Technical University, 83, Lermontov St., Irkutsk, 664074, Russia
- A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, 1 Favorsky St., Irkutsk, 664033, Russia
| | - Eric Koffi Kouame
- Irkutsk National Research Technical University, 83, Lermontov St., Irkutsk, 664074, Russia
- A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, 1 Favorsky St., Irkutsk, 664033, Russia
| | - Marat M Khusniyarov
- Department of Chemistry and Pharmacy, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Egerlandstrasse 1, 91058, Erlangen, Germany
| |
Collapse
|
8
|
Theoretical Study on the Structures, Electronic Properties, and Aromaticity of Thiophene Analogues of Anti-Kekulene. CHEMISTRY 2022. [DOI: 10.3390/chemistry4040102] [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
We predict the geometries, electronic properties, and aromaticity of thiophene analogues of anti-kekulene with six to nine thiophene rings 1–4, together with those of cyclobutadithiophenes (CDTs) and anti-kekulene as reference compounds, using density functional theory calculations. Investigation of the simplest reference compounds, CDTs, reveals that the local aromaticity of their thiophene rings is influenced by their fused position (b- or c-bond) to the four-membered ring (4MR). A thiophene ring fused at the b-position (b-TR) retains its aromatic character to some extent, whereas the aromatic character of one fused at the c-position is attenuated. The 4MR with two fused b-TRs retains a strong anti-aromatic character. Thiophene analogues of anti-kekulene with six to eight thiophene rings 1–3 favor bowl-shaped structures, in contrast to the planar structure of anti-kekulene, because of the shorter distances of the sulfur bridges. Compound 4, with nine thiophene rings, adopts a planar structure. The local aromaticity and anti-aromaticity of the thiophene ring and 4MR are significantly attenuated in 1–4 compared with the reference compounds, the CDTs and anti-kekulene. This can be attributed to the considerable contribution of the quinoidal electronic structure in 1–4. The present study provides new insight into the aromatic and electronic nature of systems containing cyclobutadienothiophene.
Collapse
|