Counterion and solvation effects on the conformations of the radical anions of 2,5-dicyanovinyl substituted furan and thiophene. An EPR and ENDOR study
- 1 January 1992
- journal article
- research article
- Published by Royal Society of Chemistry (RSC) in Journal of the Chemical Society, Perkin Transactions 2
- No. 12,p. 2137-2143
- https://doi.org/10.1039/p29920002137
Abstract
The radical anions of two tetranitrile compounds, i.e., 2,2′-(furan-2,5-diyldimethylidene)-bispropanedinitrile (1) and 2,2′-(thiophene-2,5-diyldimethylidene)bispropanedinitrile (2), have been investigated in a 1,2-dimethoxyethane/N,N,N′,N′,N″,N″-hexamethylphosphoric triamide mixture, 1,2-dimethoxyethane, tetrahydrofuran, and 2-methyltetrahydrofuran as the solvents and with Li+, Na+, K+, Cs+ as the counterions and in N,N-dimethylformamide with Zn2+ as counterion. A remarkable dependence of the molecular symmetry upon ion-pair formation is found for both molecules. The symmetry of both radical anions increases to C2ν under conditions favouring contact ion-pair formation.Keywords
This publication has 27 references indexed in Scilit:
- Structural Effects Determining the Reductive Electron Transfer Chemistry of 2.5-Disubstituted Furans — One and “Two-electron” Transfer Behaviour Investigated by Cyclic Voltammetry and UV/VIS/NIR-SpectroelectrochemistryZeitschrift für Physikalische Chemie, 1991
- Electron Transfer and Conformational Interconversions in 1, n ‐DiphenylpolyenesEuropean Journal of Inorganic Chemistry, 1988
- Effects of electron-transfer processes on conformationAccounts of Chemical Research, 1986
- Effects of ion pair association on the barrier to hindered internal rotation in nitrobenzophenone and dinitrobenzophenone radical anionsThe Journal of Physical Chemistry, 1983
- Electron spin resonance study of the radical anion of p-bis(pentamethylbenzoyl)benzeneJournal of the Chemical Society, Faraday Transactions 2: Molecular and Chemical Physics, 1982
- Electron spin resonance investigation of the reduction of o-diaroylbenzenes by main group II metalsJournal of the Chemical Society, Faraday Transactions 2: Molecular and Chemical Physics, 1981
- Aliphatic semidiones. XXII. Acyclic dialkyl-1,2-semidionesJournal of the American Chemical Society, 1974
- Effects of ion par formation on the electron paramagnetic resonance parameters of radical anionsJournal of the American Chemical Society, 1971
- Application of electron spin resonance spectroscopy to problems of structure and conformation. XXIII. Ion pairing in alkali metal salts of biacetyl and perfluorobiacetyl. Mechanism of the homogeneous reduction of an .alpha.-diketone by lithium metal and an example of a remarkably slow equilibrationJournal of the American Chemical Society, 1971
- ESR Study of Rotational Isomerism in Substituted Benzaldehyde AnionsThe Journal of Chemical Physics, 1963