1
|
Shu C, Yang Z, Rajca A. From Stable Radicals to Thermally Robust High-Spin Diradicals and Triradicals. Chem Rev 2023; 123:11954-12003. [PMID: 37831948 DOI: 10.1021/acs.chemrev.3c00406] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2023]
Abstract
Stable radicals and thermally robust high-spin di- and triradicals have emerged as important organic materials due to their promising applications in diverse fields. New fundamental properties, such as SOMO/HOMO inversion of orbital energies, are explored for the design of new stable radicals, including highly luminescent ones with good photostability. A relation with the singlet-triplet energy gap in the corresponding diradicals is proposed. Thermally robust high-spin di- and triradicals, with energy gaps that are comparable to or greater than a thermal energy at room temperature, are more challenging to synthesize but more rewarding. We summarize a number of high-spin di- and triradicals, based on nitronyl nitroxides that provide a relation between the experimental pairwise exchange coupling constant J/k in the high-spin species vs experimental hyperfine coupling constants in the corresponding monoradicals. This relation allows us to identify outliers, which may correspond to radicals where J/k is not measured with sufficient accuracy. Double helical high-spin diradicals, in which spin density is delocalized over the chiral π-system, have been barely explored, with the sole example of such high-spin diradical possessing alternant π-system with Kekulé resonance form. Finally, we discuss a high-spin diradical with electrical conductivity and derivatives of triangulene diradicals.
Collapse
Affiliation(s)
- Chan Shu
- Department of Chemistry, University of Nebraska, Lincoln, Nebraska 68588-0304, United States
| | - Zhimin Yang
- Department of Chemistry, University of Nebraska, Lincoln, Nebraska 68588-0304, United States
| | - Andrzej Rajca
- Department of Chemistry, University of Nebraska, Lincoln, Nebraska 68588-0304, United States
| |
Collapse
|
2
|
Zayakin I, Tretyakov E, Akyeva A, Syroeshkin M, Burykina J, Dmitrenok A, Korlyukov A, Nasyrova D, Bagryanskaya I, Stass D, Ananikov V. Overclocking Nitronyl Nitroxide Gold Derivatives in Cross-Coupling Reactions. Chemistry 2023; 29:e202203118. [PMID: 36259387 DOI: 10.1002/chem.202203118] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Indexed: 12/12/2022]
Abstract
Nitronyl nitroxides are functional building blocks in cutting-edge research fields, such as the design of molecular magnets, the development of redox and photoswitchable molecular systems and the creation of redox-active components for organic and hybrid batteries. The key importance of the nitronyl nitroxide function is to translate molecular-level-optimized structures into nano-scale devices and new technologies. In spite of great importance, efficient and versatile synthetic approaches to these compounds still represent a challenge. Particularly, methods for the direct introduction of a nitronyl nitroxide moiety into aromatic systems possess many limitations. Here, we report gold derivatives of nitronyl nitroxide that can enter Pd(0)-catalysed cross-coupling reactions with various aryl bromides, affording the corresponding functionalized nitronyl nitroxides. Based on the high thermal stability and enhanced reactivity in catalytic transformation, a new reagent is suggested for the synthesis of radical systems via a universal cross-coupling approach.
Collapse
Affiliation(s)
- Igor Zayakin
- N. D. Zelinsky Institute of Organic Chemistry, 47 Leninsky Prosp., 119991, Moscow, Russia
| | - Evgeny Tretyakov
- N. D. Zelinsky Institute of Organic Chemistry, 47 Leninsky Prosp., 119991, Moscow, Russia
| | - Anna Akyeva
- N. D. Zelinsky Institute of Organic Chemistry, 47 Leninsky Prosp., 119991, Moscow, Russia
| | - Mikhail Syroeshkin
- N. D. Zelinsky Institute of Organic Chemistry, 47 Leninsky Prosp., 119991, Moscow, Russia
| | - Julia Burykina
- N. D. Zelinsky Institute of Organic Chemistry, 47 Leninsky Prosp., 119991, Moscow, Russia
| | - Andrey Dmitrenok
- N. D. Zelinsky Institute of Organic Chemistry, 47 Leninsky Prosp., 119991, Moscow, Russia
| | - Alexander Korlyukov
- A. N. Nesmeyanov Institute of Organoelement Compounds, 28 Vavilov Str., 119991, Moscow, Russia
| | - Darina Nasyrova
- N. D. Zelinsky Institute of Organic Chemistry, 47 Leninsky Prosp., 119991, Moscow, Russia
| | - Irina Bagryanskaya
- N. N. Vorozhtsov Novosibirsk Institute of Organic Chemistry, 9 Akad. Lavrentyev Prosp., 630090, Novosibirsk, Russia
| | - Dmitri Stass
- V. V. Voevodsky Institute of Chemical Kinetics and Combustion, 3 Institutskaya Str., 630090, Novosibirsk, Russia
| | - Valentine Ananikov
- N. D. Zelinsky Institute of Organic Chemistry, 47 Leninsky Prosp., 119991, Moscow, Russia
| |
Collapse
|
3
|
Nitronyl-nitroxide PCP-pincer complexes of palladium and nickel: synthesis and an EPR study. Russ Chem Bull 2022. [DOI: 10.1007/s11172-022-3560-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
|
4
|
Nishiuchi T, Ishii D, Aibara S, Sato H, Kubo T. Synthesis, properties and chemical modification of a persistent triisopropylsilylethynyl substituted tri(9-anthryl)methyl radical. Chem Commun (Camb) 2022; 58:3306-3309. [PMID: 35178540 DOI: 10.1039/d2cc00548d] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
In studies aimed at developing new organic spin materials, we prepared a triisopropylsilylethynyl substituted tri(9-anthryl)methyl (TAntM) radical. The TIPS-ethynyl group in this radical effectively suppresses its reactivity, resulting in extremely high stability in air for at least one month. Chemical modification of the radical using [4+2] Diels-Alder reaction proceeds even at room temperature. Because harsh conditions and metal-catalyzed reactions are not required, this post-modification strategy should be highly versatile for use in constructing unique spin-labelled molecules.
Collapse
Affiliation(s)
- Tomohiko Nishiuchi
- Department of Chemistry, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan. .,Innovative Catalysis Science Division, Institute for Open and Transdisciplinary Research Initiatives, (ICS-OTRI), Osaka University, Suita, Osaka 565-0871, Japan
| | - Daisuke Ishii
- Department of Chemistry, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan.
| | - Seito Aibara
- Department of Chemistry, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan.
| | - Hiroyasu Sato
- Rigaku Corporation, 3-9-12 Matsubara, Akishima, Tokyo 196-8666, Japan
| | - Takashi Kubo
- Department of Chemistry, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan. .,Innovative Catalysis Science Division, Institute for Open and Transdisciplinary Research Initiatives, (ICS-OTRI), Osaka University, Suita, Osaka 565-0871, Japan
| |
Collapse
|
5
|
Tretyakov EV, Ovcharenko VI, Terent'ev AO, Krylov IB, Magdesieva TV, Mazhukin DG, Gritsan NP. Conjugated nitroxide radicals. RUSSIAN CHEMICAL REVIEWS 2022. [DOI: 10.1070/rcr5025] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
6
|
Kira S, Miyamae T, Yoshida K, Kanzaki Y, Sugisaki K, Shiomi D, Sato K, Takui T, Suzuki S, Kozaki M, Okada K. Aurophilic Interactions in Multi-Radical Species: Electronic-Spin and Redox Properties of Bis- and Tris-[(Nitronyl Nitroxide)-Gold(I)] Complexes with Phosphine-Ligand Scaffolds. Chemistry 2021; 27:11450-11457. [PMID: 34038598 DOI: 10.1002/chem.202101483] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Indexed: 01/23/2023]
Abstract
Multinuclear AuI complexes with two or three nitronyl nitroxide-2-ide radical anion and phosphine-ligand scaffolds, (NN-Au)2 -1 o, (NN-Au)2 -1 m, and (NN-Au)2 -1 p, have been synthesized to investigate the influence of AuI -AuI (aurophilic) interactions on the properties of multispin molecular systems. The desired complexes were successfully prepared in moderate yields in a one-pot synthesis from the corresponding phosphine ligand, AuI source, parent NN, and sodium hydroxide. Among the prepared complexes, (NN-Au)2 -1 o, in which an aurophilic interaction was clearly observed by crystal structure analysis, showed characteristic spin-spin interactions, electrochemical properties, and solvatochromic behavior. The results from theoretical calculations also suggested that the differences in properties between complex (NN-Au)2 -1 o and the other complexes are due to intramolecular aurophilic interactions.
Collapse
Affiliation(s)
- Sayaka Kira
- Graduate School of Science, Osaka City University Sumiyoshi-ku, Osaka, Osaka 558-8585, Japan
| | - Takayuki Miyamae
- Graduate School of Science, Osaka City University Sumiyoshi-ku, Osaka, Osaka 558-8585, Japan
| | - Kohei Yoshida
- Graduate School of Science, Osaka City University Sumiyoshi-ku, Osaka, Osaka 558-8585, Japan
| | - Yuki Kanzaki
- Graduate School of Science, Osaka City University Sumiyoshi-ku, Osaka, Osaka 558-8585, Japan
| | - Kenji Sugisaki
- Graduate School of Science, Osaka City University Sumiyoshi-ku, Osaka, Osaka 558-8585, Japan
| | - Daisuke Shiomi
- Graduate School of Science, Osaka City University Sumiyoshi-ku, Osaka, Osaka 558-8585, Japan
| | - Kazunobu Sato
- Graduate School of Science, Osaka City University Sumiyoshi-ku, Osaka, Osaka 558-8585, Japan
| | - Takeji Takui
- Graduate School of Science, Osaka City University Sumiyoshi-ku, Osaka, Osaka 558-8585, Japan
| | - Shuichi Suzuki
- Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan
| | - Masatoshi Kozaki
- Graduate School of Science, Osaka City University Sumiyoshi-ku, Osaka, Osaka 558-8585, Japan.,Osaka City University Advanced Research Institute for Natural Science and Technology (OCARINA), Osaka City University Sumiyoshi-ku, Osaka, Osaka 558-8585, Japan
| | - Keiji Okada
- Graduate School of Science, Osaka City University Sumiyoshi-ku, Osaka, Osaka 558-8585, Japan.,Osaka City University Advanced Research Institute for Natural Science and Technology (OCARINA), Osaka City University Sumiyoshi-ku, Osaka, Osaka 558-8585, Japan
| |
Collapse
|
7
|
Rausch R, Krause AM, Krummenacher I, Braunschweig H, Würthner F. Nitronyl Nitroxide Bifunctionalized Electron-Poor Chromophores: Synthesis of Stable Dye Biradicals by Lewis Acid Promoted Desilylation. J Org Chem 2021; 86:2447-2457. [PMID: 33434018 DOI: 10.1021/acs.joc.0c02613] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Open shell organic molecules bearing π-cores are of great interest for optical, electronic, and magnetic applications but frequently suffer fast decomposition or lack synthetic accessibility. In this regard, nitronyl nitroxides are promising candidates for stable (bi-)radicals due to their high degree of spin delocalization along the O-N-C-N-O pentad unit. Unfortunately, they are limited to electron-rich systems so far. To overcome this limitation, we developed a synthetic procedure for the twofold spin decoration of electron-poor chromophores (Ered = -1158 mV) with nitronyl nitroxide radical moieties via selective deprotection/oxidation of the respective silylated precursors with boron fluoride and subsequent quenching with tetraethyl orthosilicate. Nitronyl nitroxide biradicals PBI-NN, IIn-NN, PhDPP-NN, ThDPP-NN, and FuDPP-NN bridged by perylene bisimide (PBI), isoindigo (IIn), and diketopyrrolopyrrole (DPP) pigment colorants were finally obtained as bench stable compounds after periodate oxidation with yields of 60-81%. The absorption spectral signatures of the chromophores remain preserved in the open shell state and match the ones of the pristine parent compounds, which allowed an a priori prediction of their optical properties. Consequently, we achieved twofold spin labeling while keeping the intrinsic properties of the electron deficient chromophores intact.
Collapse
Affiliation(s)
- Rodger Rausch
- Institut für Organische Chemie, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Ana-Maria Krause
- Institut für Organische Chemie, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.,Center for Nanosystems Chemistry (CNC), Universität Würzburg, Theodor-Boveri-Weg, 97074 Würzburg, Germany
| | - Ivo Krummenacher
- Institut für Anorganische Chemie and Institute for Sustainable Chemistry and Catalysis with Boron, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Holger Braunschweig
- Institut für Anorganische Chemie and Institute for Sustainable Chemistry and Catalysis with Boron, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Frank Würthner
- Institut für Organische Chemie, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.,Center for Nanosystems Chemistry (CNC), Universität Würzburg, Theodor-Boveri-Weg, 97074 Würzburg, Germany
| |
Collapse
|
8
|
Synthesis and Structure of (Nitronyl Nitroxide-2-ido)(tert-butyldiphenylphosphine)gold(I) and -(Di(tert-butyl)phenylphosphine)gold(I) Derivatives; Their Comparative Study in the Cross-Coupling Reaction. CRYSTALS 2020. [DOI: 10.3390/cryst10090770] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
We synthesized two new organogold derivatives of a nitronyl nitroxide (NN) with phosphine ligands, namely NN-Au-PtBuPh2 and NN-Au-PtBu2Ph. They were characterized by X-ray diffraction analysis, cyclic voltammetry, and ESR, IR, and UV/Vis spectroscopy. The X-ray structural analysis revealed a tendency of the NN moiety to form a large number of short intermolecular contacts. This phenomenon is related to the anionic nature of the paramagnetic group NN, as evidenced by a significantly lower oxidation potential in comparison with purely organic derivatives of NN radicals. The cross-coupling reaction of NN-Au-PPh3, NN-Au-PtBuPh2, or NN-Au-PtBu2Ph with an activated bromoarene, namely, p-BrC6H4NO2, was investigated. It was shown that regardless of the presence of the bulky tert-butyl substituent, all gold derivatives have similar activities in the cross-coupling reaction and give a cross-coupling product, NN-C6H4NO2, with comparable yields.
Collapse
|
9
|
Suzuki S, Nakamura F, Naota T. Environmentally Benign Strategy for Arylation of Nitronyl Nitroxide Using a Non-Transition Metal Nucleophile. Org Lett 2020; 22:1350-1354. [PMID: 32011895 DOI: 10.1021/acs.orglett.9b04655] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We have developed a method for the arylation of nitronyl nitroxide without using its transition metal complex as a nucleophile. Various nitronyl nitroxide-substituted π-electronic compounds can be obtained from the parent nitronyl nitroxide and the corresponding aryl iodides using a combination of zero-valent palladium catalysts and a 2-dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl ligand in the presence of sodium tert-butoxide. The utility of the method has been demonstrated by the direct synthesis of open-shell compounds with giant π-electronic systems, such as 10P.
Collapse
Affiliation(s)
- Shuichi Suzuki
- Department of Chemistry, Graduate School of Engineering Science , Osaka University , 1-3 Machikaneyama , Toyonaka , Osaka 560-8531 , Japan
| | - Fumiya Nakamura
- Department of Chemistry, Graduate School of Engineering Science , Osaka University , 1-3 Machikaneyama , Toyonaka , Osaka 560-8531 , Japan
| | - Takeshi Naota
- Department of Chemistry, Graduate School of Engineering Science , Osaka University , 1-3 Machikaneyama , Toyonaka , Osaka 560-8531 , Japan
| |
Collapse
|