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The Radical Anions of N , N ′‐Dicyanoquinone Diimines, a New Class of Electron Acceptors
Author(s) -
Gerson Fabian,
Gescheidt Georg,
Möckel Reinhart,
Aumüller Alexander,
Erk Peter,
Hünig Siegfried
Publication year - 1988
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.19880710712
Subject(s) - chemistry , hyperfine structure , diimine , electron paramagnetic resonance , ion , coupling constant , radical ion , hyperfine coupling , crystallography , proton , spectroscopy , photochemistry , radical , nuclear magnetic resonance , atomic physics , organic chemistry , physics , particle physics , quantum mechanics , catalysis
The radical anions of 12 N , N ′‐dicyanoquinone diimines, a new class of electron acceptors, hace been characterized by their hyperfine data with the use of ESR and ENDOR spectroscopy. The largest coupling constant (0.30–0.45 mT), due to the two 14 N nuclei in the exocyclic positions, gives rise to a conspicuous broadening of the peripheral ESR lines by an incomplete averaging of the hyperfine anisotropy. The most plausible interpretation of the experimental results for the radical anions of N , N ′‐dicyano‐ 1,4‐benzoquinone diimine ( 1 ) and N , N ′‐Dicyano‐9,10‐anthraquinone diimine ( 9 ) is in terms of both ‘syn’ ‐ and ‘anti’ ‐configurations contributing to the ESR and ENDOR spectra and having equal proton‐ and 14 N‐coupling constants. The π‐spin distribution in the radical anions of N , N ′‐dicyanoquinone diimines is compared with those in the analogous ions of tetracyanoquinodimethanes and quinones.