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The ESR. Spectrum of the Radical Anion of 1,1,2,2,9,9,10,10‐Octafluoro [2.2]paracyclophane
Author(s) -
Gerson Fabian,
OhyaNishiguchi Hiroaki,
Plattner Georges
Publication year - 1982
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.19820650213
Subject(s) - chemistry , ion , perchlorate , hyperfine structure , radical ion , dimethoxyethane , benzene , population , crystallography , medicinal chemistry , electrolyte , atomic physics , organic chemistry , physics , demography , electrode , sociology
Abstract The radical anion of 1,1,2.2,9,9,10, 10‐octafluoro[2.2]paracyclophane ( 1 ) has been generated by electrolytic reduction of 1 in 1,2‐dimethoxyethane (tetrabutylammonium perchlorate as the supporting salt). The hyperfine coupling constants of the eight 19 F‐nuclei and the eight protons, a f = 3.35 and a H ≈ 0.10 mT, are qualitatively reproduced by INDO. calculations. According to these calculations, the singly occupied orbital of 1 ⊖ can be represented by an A g ‐combination of two ‘symmetric’ benzene LUMO's, with a substantial transfer of spin population into the 2s‐AO's of the F‐atoms. Line‐width alternation in the ESR. spectrum of 1 ⊖ indicates an ion pairing of the radical anion with its counter‐ion Bu 4 N ⊖ . The energy barrier to the migration of the cation between two equivalent sites at the radical anion is determined as 14±2 kJ/mol.