ISSN:
0018-019X
Keywords:
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The radical anions of 5H-dibenzo[a,d]cycloheptene (9), 5 H-dibenzo[c,f][1,2]diazepine (10), 5,6-dihydrodibenzo[a,e]cyclooctene (11), 5,6-dihydrodibenzo[c,g][1,2]diazocine (12), and (E)-2,2,5,5-tetramethyl-3,4-diphenylhex-3-ene (13) were characterized by ESR and ENDOR spectroscopy. Their hyperfine data were compared with those previously reported for radical anions also containing the stilbene or the azobenzene π-system. Whereas the π-spin distribution in the radical anions of the stilbene series is only moderately sensitive to deviations of the π-system from planarity, the radical anions of the azobenzene series respond to steric strain by shifting the π-spin population from the benzene rings to the azo group. This finding is impressively demonstrated by the similar hyperfine data for 9· - and 11· - which contrast with the strongly highly hindered 13· -. A. plausible interpretation is readily provided by the electron affinities of the constituent π-moieties in stilbene and azobenzene. While those of benzene and ethene are both comparatively low, the azo group has a considerably higher electron affinity.
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/hlca.19960790130
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