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Dianion and Tetraanion of [2 4 ] Paracyclophanetetraene—New Unusual Perimeter Systems
Author(s) -
Huber Walter,
Müllen Klaus,
Wennerström Olof
Publication year - 1980
Publication title -
angewandte chemie international edition in english
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 0570-0833
DOI - 10.1002/anie.198006241
Subject(s) - benzene , perimeter , ring (chemistry) , chemistry , crystallography , stereochemistry , organic chemistry , mathematics , geometry
The existence of peripheral ring currents in the dianion and the tetraanion of (1) is manifested in the NMR spectra. In the case of (1) , the dianion, and the tetraanion, H‐3 (outer) absorbs at δ = 7.37, 9.26, and 4.48, respectively, and H‐4 (inner) at 7.37, −7.07 (!), and 12.76, respectively. From the viewpoint of bonding theory, it is particularly surprising that perimeter conjugation extends beyond the benzene units.