Synthesis and EPR studies of radicals and biradical anions of C{sub 60} nitroxide derivatives

Arena, F; Bullo, F; Conti, F; Corvaja, C; Maggini, M; Scorrano, G; Prato, M

doi:10.1021/ja9626291

Title: Synthesis and EPR studies of radicals and biradical anions of C{sub 60} nitroxide derivatives

Full Record
Other Related Research

Abstract

A series of C{sub 60} derivatives substituted with the nitroxide group 2,2,6,6-tetramethylpiperidine-1-oxyl have been synthesized. A detailed EPR and ENDOR study of the neutral radicals and of their reduction products is reported. All the neutral species give EPR spectra consisting of a main triplet of lines with = 15 G splitting by the {sup 14}N nucleus, typical of nitroxide radicals. Some of them show additional well-resolved splittings by methyl and methylene protons, which are discussed in relation to the conformation of the nitroxide ring. When the compounds are progressively reduced under vacuum by contact with an alkali metal mirror, new EPR lines are observed; a 1:1:1 triplet with a splitting constant half that of a nitroxide radical and g = 2.0030 is attributed to biradical anions where one electron is located in the fullerene moiety and experiences a strong exchange coupling with the nitroxide unpaired electron. Frozen solution spectra of these species allow the determination of the electron-electron dipolar interaction parameters which are compared with theoretical MO calculations. The experimental values agree with a spin distribution of one unpaired electron mostly in the equatorial plane of the fullerene. Another single line which appears in the spectrum as the reduction proceedsmore »« less

Authors:

Arena, F; Bullo, F; Conti, F; Corvaja, C; Maggini, M; Scorrano, G ^[1]; Prato, M ^[2]

Universita di Padova (Italy)
Universita di Trieste (Italy)

Publication Date:: Wed Jan 29 00:00:00 EST 1997

OSTI Identifier:: 458611

Resource Type:: Journal Article

Journal Name:: Journal of the American Chemical Society

Additional Journal Information:: Journal Volume: 119; Journal Issue: 4; Other Information: PBD: 29 Jan 1997

Country of Publication:: United States

Language:: English

Subject:: 36 MATERIALS SCIENCE; 40 CHEMISTRY; 66 PHYSICS; FULLERENES; DERIVATIZATION; RADICALS; SYNTHESIS; ELECTRON SPECTRA; ELECTRON SPIN RESONANCE; ANIONS; ORGANIC NITROGEN COMPOUNDS; MOLECULAR ORBITAL METHOD

Citation Formats


                    Arena, F, Bullo, F, Conti, F, Corvaja, C, Maggini, M, Scorrano, G, and Prato, M. Synthesis and EPR studies of radicals and biradical anions of C{sub 60} nitroxide derivatives.  United States: N. p., 1997. 
        Web.  doi:10.1021/ja9626291.

Copy to clipboard


                    Arena, F, Bullo, F, Conti, F, Corvaja, C, Maggini, M, Scorrano, G, & Prato, M. Synthesis and EPR studies of radicals and biradical anions of C{sub 60} nitroxide derivatives.  United States.  https://doi.org/10.1021/ja9626291

Copy to clipboard


                    Arena, F, Bullo, F, Conti, F, Corvaja, C, Maggini, M, Scorrano, G, and Prato, M. 1997.  
        "Synthesis and EPR studies of radicals and biradical anions of C{sub 60} nitroxide derivatives".  United States.  https://doi.org/10.1021/ja9626291.

Copy to clipboard


                    
@article{osti_458611,

  title        = {Synthesis and EPR studies of radicals and biradical anions of C{sub 60} nitroxide derivatives},

  author       = {Arena, F and Bullo, F and Conti, F and Corvaja, C and Maggini, M and Scorrano, G and Prato, M},

  abstractNote = {A series of C{sub 60} derivatives substituted with the nitroxide group 2,2,6,6-tetramethylpiperidine-1-oxyl have been synthesized. A detailed EPR and ENDOR study of the neutral radicals and of their reduction products is reported. All the neutral species give EPR spectra consisting of a main triplet of lines with = 15 G splitting by the {sup 14}N nucleus, typical of nitroxide radicals. Some of them show additional well-resolved splittings by methyl and methylene protons, which are discussed in relation to the conformation of the nitroxide ring. When the compounds are progressively reduced under vacuum by contact with an alkali metal mirror, new EPR lines are observed; a 1:1:1 triplet with a splitting constant half that of a nitroxide radical and g = 2.0030 is attributed to biradical anions where one electron is located in the fullerene moiety and experiences a strong exchange coupling with the nitroxide unpaired electron. Frozen solution spectra of these species allow the determination of the electron-electron dipolar interaction parameters which are compared with theoretical MO calculations. The experimental values agree with a spin distribution of one unpaired electron mostly in the equatorial plane of the fullerene. Another single line which appears in the spectrum as the reduction proceeds further on (g = 1.9999) is attributed to a new species: possibly a substituted fullerene radical anion in which the nitroxide group is irreversibly reduced. 29 refs., 5 figs., 2 tabs.},

  doi          = {10.1021/ja9626291},

  url          = {https://www.osti.gov/biblio/458611},
  journal      = {Journal of the American Chemical Society},
number       = 4,

  volume       = 119,

  place        = {United States},

  year         = {Wed Jan 29 00:00:00 EST 1997},

  month        = {Wed Jan 29 00:00:00 EST 1997}

}

Copy to clipboard

Journal Article:

https://doi.org/10.1021/ja9626291

Other availability

Find in Google Scholar

Search WorldCat to find libraries that may hold this journal

Save / Share:

Export Metadata

Save to My Library

Similar records in OSTI.GOV collections:

Heterospin biradicals based on new piperidineoxyl-substituted 3,6-di-tert-butyl-o-benzoquinone

Journal Article Egorova, E.; Druzhkov, N.; Kozhanov, K.; ... - Russian Chemical Bulletin

A nucleophilic addition reaction of 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (OH-TEMPO) to 3,6-di-tert-butyl-o-benzoquinone was used to obtain a new sterically hindered o-benzoquinone (1) containing 2,2,6,6-tetramethylpiperidineoxyl functional group, which was characterized by IR spectroscopy, mass spectrometry, elemental analysis, and X-ray diffraction. A one-electron reduction of 1 with potassium and thallium is an efficient method for the generation of earlier unknown heterospin biradicals 5a and 5b, respectively, containing nitroxide and o-semiquinone radical centers. Analysis of the hyperfine structure of the ESR spectra of biradicals 5a and 5b in solution showed that they belong to the group of heterospin biradicals with strong (J >> a) and fastmore »« less
https://doi.org/10.1007/S11172-017-1934-1
Photoinduced electron transfer from dialkyl nitroxides to halogenated solvents

Journal Article Chateauneuf, J; Lusztyk, J; Ingold, K - Journal of Organic Chemistry; (United States)

Laser flash photolysis (LFP) at wavelengths within the charge-transfer absorption present in CCl{sub 4} solutions of 2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPO) yields the oxoammonium chloride of TEMPO, 1 ({lambda}{sub max} = 460 nm), and the trichloromethyl radical in an essentially instantaneous ({le}18 ps) process. The primary photochemical event is an electron transfer from TEMPO to CCl{sub 4}, and this is followed by immediate decomposition of the CCl{sub 4}{sup {sm bullet}{minus}} radical anion to Cl{sup {minus}} and Cl{sub 3}C{sup {sm bullet}}. An independent synthesis of 1 confirmed that the absorption attributed to this species has been correctly assigned. The formation of Cl{sub 3}C{sup {smmore »« less
https://doi.org/10.1021/jo00290a046
Mechanism of Electrochemical Oxidation of Nitroxide Radicals in Ethaline Deep Eutectic Solvent

Journal Article Shaheen, Nora; Ijjada, Mahesh; Vukmirovic, Miomir; ... - Journal of the Electrochemical Society

Deep eutectic solvents (DESs) are emerging as promising electrolytes for electrochemical energy storage applications. Electroactive nitroxide-radical-containing organics can be dissolved in DESs to facilitate redox reactions; however, mechanistic know-how of their charge transfer kinetics at the electrode surface is rather limited. In this work, we investigate the mechanism underlying the electrochemical oxidation of 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) and 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (4-hydroxy-TEMPO). Using polarization measurements on a platinum rotating disk electrode and micro-electrode, we show that the anodic charge transfer coefficient ($$\alpha $$) for one-electron transfer oxidations of TEMPO and 4-hydroxy-TEMPO approaches 0.9 in DES as well as in aqueous electrolytes, i.e., a significantmore »« less
https://doi.org/10.1149/1945-7111/abc439

Full Text Available
Molecular Dynamics Simulation Study of Solvent and State of Charge Effects on Solid-Phase Structure and Counterion Binding in a Nitroxide Radical Containing Polymer Energy Storage Material

Journal Article Kemper, Travis; Gennett, Thomas; Larsen, Ross - Journal of Physical Chemistry. C

Here we performed molecular dynamics simulations to understand the effects of solvent swelling and state of charge (SOC) on the redox active, organic radical cathode material poly(2,2,6,6-tetramethylpiperidinyloxy methacrylate) (PTMA). We show that the polar solvent acetonitrile primarily solvates the nitroxide radical without disrupting the packing of the (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO) pendant groups of PTMA. We also simulated bulk PTMA in different SOC, 25%, 50%, 75%, and 100%, by converting the appropriate number of TEMPO groups to the cation charge state and adding BF₄^- counterions to the simulation. At each SOC the packing of PTMA, the solvent, and the counterions were examined.more »« less
Cited by 15
https://doi.org/10.1021/acs.jpcc.6b07118

Full Text Available
Paramagnetic probe for molecular interactions: I. EPR and electronic absorption studies of lithium cation solvation by a nitroxide radical

Journal Article Kolodziejski, W - J. Solution Chem.; (United States)

The 2,2,6,6-tetramethylpiperidine nitroxide radical (TMPN) was studied by EPR and electronic absorption spectroscopy in LiClO/sub 4/ solutions in various organic solvents. The /sup 14/N hyperfine structure, together with the exchange broadening of its components in EPR and the electronic n..--> pi.. transition in the visible region, provide useful information about Li/sup +/-TMPN complexes. Both spectroscopic methods prove that the oxygen atom of TMPN was involved in the Li/sup +/-TMPN interaction. The complex formation constants 15.61, 2.50, 0.75, 0.61, 0.75, and 0.33 dm/sup 3/-mol/sup -1/ were found in nitromethane, benzonitrile, acetonitrile, propylene carbonate, acetone and tetrahydrofurane, respectively. These formation constants weremore »« less
https://doi.org/10.1007/BF00645813

Similar Records