Two-Electron Multicenter Bonding (‘Pancake Bonding’) in Dimers of 5,6-Dichloro-2,3-dicyanosemiquinone (DDQ) Radical Anions

Total yields of paramagnetic species, their optical bleaching and thermal annealing in acetic, propionic, a-butyric, isobutyric, and pivalic acid γ-irradiated at 77 K were followed by ESR spectroscopy. Radical anions, always found after irradiation, disappear during optical bleaching without formation of any paramagnetic product. During thermal annealing they are converted almost quantitatively into the α-radicals of the respective acid, with the exception of pivalic acid. Amounts of radical anions were estimated from the difference of integrated ESR spectra taken before and after optical bleaching. The results show that approximately equal amounts of the reduction and oxidation paramagnetic products of the γ-irradiation can be detected.

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Stability of radical anions derived from substituted 5-nitrofurans investigated by ESR spectroscopy

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19851594 ◽

1985 ◽

Vol 50 (7) ◽

pp. 1594-1601 ◽

Cited By ~ 5

Author(s):

Jiří Klíma ◽

Larisa Baumane ◽

Janis Stradinš ◽

Jiří Volke ◽

Romualds Gavars

Keyword(s):

Radical Anion ◽

High Stability ◽

Esr Spectroscopy ◽

Reaction Path ◽

Order Reaction ◽

Second Order ◽

Radical Anions ◽

Second Order Reaction ◽

Unpaired Electron Density ◽

The Stability

It has been found that the decay in dimethylformamide and dimethylformamide-water mixtures of radical anions in five of the investigated 5-nitrofurans is governed by a second-order reaction. Only the decay of the radical anion generated from 5-nitro-2-furfural III may be described by an equation including parallel first- and second-order reactions; this behaviour is evidently caused by the relatively high stability of the corresponding dianion, this being an intermediate in the reaction path. The presence of a larger conjugated system in the substituent in position 2 results in a decrease of the unpaired electron density in the nitro group and, consequently, an increase in the stability of the corresponding radical anions.

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Pulse radiolytic kinetic study of the decay of .alpha.-methyl-substituted benzoquinone radical anions: a possible mechanistic model for bioreductive alkylation

Journal of the American Chemical Society ◽

10.1021/ja00002a032 ◽

1991 ◽

Vol 113 (2) ◽

pp. 611-615 ◽

Cited By ~ 14

Author(s):

Kevin E. O'Shea ◽

Marye Anne Fox

Keyword(s):

Kinetic Study ◽

Mechanistic Model ◽

Radical Anions

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Magnetostructural relationships in [Ni(dmit)2] − radical anions

Dalton Transactions ◽

10.1039/d1dt00734c ◽

2021 ◽

Author(s):

Jhon Enrique Zapata Rivera ◽

Carmen J. Calzado

Keyword(s):

Magnetic Properties ◽

Radical Anions ◽

The Relationship

This work explores the relationship between the magnetic properties of salts based on the [Ni(dmit)2]− radicals and the different arrangement that these radicals can adopt in the crystals, induced by...

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