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The Dianions of Pyrene and Pyrene Isomers as (4n)π‐Perimeters
Author(s) -
Müllen Klaus
Publication year - 1978
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.19780610704
Subject(s) - chemistry , pyrene , computational chemistry , spectroscopy , density functional theory , photochemistry , organic chemistry , physics , quantum mechanics
Metal reduction of pyrene and of pyrene isomers under carefully controlled conditions yields the corresponding dianions. The properties of the neutral compounds and of the dianions are studied via 1 H‐NMR. spectroscopy. Whereas the former exhibit similar behaviour, the charge distribution within the dianionic species proves to be very different. As a consequence, some of the polycyclic dianions can be regarded essentially as (4n)π‐perimeters, an approach which is satisfactorily rationalized by simple MO‐models. Further evidence in favour of this bonding scheme comes from the ESR. spectroscopic measurement of the spin density distribution within the corresponding radical anions.