Synthese und Eigenschaften von σ-verbrückten Anthracen-Viologenen

Abstract

The synthesis of the donor-acceptor compounds 2, 7, and 12 where the anthracene donor and the viologen acceptor are linked by a saturated bridge (polymethylene or the bicyclo[2.2.2]octanyl moiety) is described. While the preparation of 2a-c is straightforward, new procedures for the synthesis of the bicyclo compounds 7 and 12 had to be developed. Unexpectedly, the viologens 13d, e could be obtained by direct nucleophilic substitution of the corresponding tertiary and neopentyl-type alkyl tosylates with 4,4-bipyridine. By comparison of the emission spectra of the compounds 2a and 12a, b the strong fluorescence quenching indicates an electron transfer from the donor to the acceptor.