Journal ArticleDOI
Electron spin resonance study and theoretical calculations of some methoxybenzene radical cations
TLDR
In this paper, the spin densities obtained from these calculations have been correlated with bibliographic data on the reactivity of N,N-dialkylaniline radical cations under nucleophilic attack.Abstract:
Reaction of methoxybenzene derivatives with phenyliodine(III) bis(trifluoro-acetate), PIFA, yielded the corresponding radical cations, which were observed and characterized by ESR and visible spectroscopies. The application of this methodology to this kind of compound has allowed well-resolved ESR spectra to be obtained of the one-electron oxidized compounds, thus determining the hyperfine coupling constants of the cation radical when the solvent was 1,1,1,3,3,3-hexafluoropropanol (HFP). The requirements of the substitution pattern of the aromatic ring have been studied. In contrast, it was not possible to obtain the ESR spectra of N,N-dialkylaniline radical cations in the same reaction conditions. The ESR spectra obtained corresponded to non-identified secondary reaction products. The spectral resolution obtained by application of this method has been compared with that obtained when the radical cations were generated by in situ electrochemical oxidation. Semiempirical calculations have allowed the coupling constants to be assigned to the magnetic centers in the radical cation. The spin densities obtained from these calculations have been correlated with bibliographic data on the reactivity of radical cations under nucleophilic attack.read more
Citations
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Journal ArticleDOI
Toward Improved Catholyte Materials for Redox Flow Batteries: What Controls Chemical Stability of Persistent Radical Cations?
Jingjing Zhang,Ilya A. Shkrob,Rajeev S. Assary,Siu on Tung,Benjamin Silcox,Larry A. Curtiss,Levi T. Thompson,Lu Zhang +7 more
TL;DR: In this paper, the authors examined factors that define the chemical and electrochemical stabilities for 1,4-dialkoxybenzene derivatives of radical cations in this family.
Journal ArticleDOI
Long‐Lived Radical Cation Salts Obtained by Interaction of Monocyclic Arenes with Niobium and Tantalum Pentahalides at Room Temperature: EPR and DFT Studies
TL;DR: The 1:3 reactions of the alkoxy arenes 1,4-F2 -2,5-(MeO)2 C6 H2 with TaF5 in chloroform at 40-50 °C resulted in formation in about 35 % yield of the long-lived radical cation salts.
Journal ArticleDOI
Room-temperature long-lived [Nb2F11]− salts of radical cations of simple arenes: EPR, UV–Vis and DFT results
TL;DR: In this article, the EPR spectra of the benzene radical salt 2-4 were compared to those of analogous 1,4-dimethoxybenzene radical species reported previously.
Journal ArticleDOI
Catalyst-Free Photoredox Addition-Cyclisations: Exploitation of Natural Synergy between Aryl Acetic Acids and Maleimide
TL;DR: Suitably functionalised carboxylic acids undergo a previously unknown photoredox reaction when irradiated with UVA in the presence of maleimide, finding it to synergistically act as a radical generating photoxidant and as aradical acceptor, negating the need for an extrinsic photOREDox catalyst.
Journal ArticleDOI
Photoinduced Electron Transfer Involving a Naphthalimide Chromophore in Switchable and Flexible [2]Rotaxanes.
TL;DR: The photoinduced electron transfer processes involving a 1,8-naphthalimide chromophore embedded in several rotaxane-based dyads were investigated by steady-state and time-resolved absorption and luminescence spectroscopic experiments.
References
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Journal ArticleDOI
Hypervalent Iodine-Induced Nucleophilic Substitution of para-Substituted Phenol Ethers. Generation of Cation Radicals as Reactive Intermediates
Yasuyuki Kita,Hirofumi Tohma,Kenji Hatanaka,Takeshi Takada,Shigekazu Fujita,Shizue Mitoh,Hiromu Sakurai,Shigenori Oka +7 more
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Molecular orbital theory of the electronic structure of organic compounds. II. Spin densities in paramagnetic species
Journal ArticleDOI
Formation of radical cations of methoxylated benzenes by reaction with hydroxyl radicals, thallium(2+), silver(2+), and peroxysulfate (SO4.-) in aqueous solution. Optical and conductometric pulse radiolysis and in situ radiolysis electron spin resonance study
Journal ArticleDOI
The Oxidation of Methoxybenzenes
Journal ArticleDOI
Making radical cations live longer
TL;DR: In this paper, the authors describe the use of HFP as a solvent for EPR spectroscopy and mechanistic studies of radical cations as intermediates in electrophilic aromatic substitution, photochemistry and spin trapping.
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