Complementary Synthetic Approaches to Elongated Polycyclic Arenes with Regioisomeric Carboxylic Substitution Patterns

Harald Bock (1) , Pauline Carré (1) , Elisabeth A. Hillard (1) , Fabien Durola (1)

1 CRPP - Centre de recherches Paul Pascal

The reaction of 1,5-dibromoanthracene with butyllithium and diethyloxalate followed by saponification gives anthrylene- 1,5-diglyoxylic acid as a bifunctional reactant. Its double condensation with 2-bromophenylacetic acid, followed by double cyclization, leads to a bright-orange nearlinear dinaphtho-anthracene-tetracarboxdiimide with substituents on the naphthalene moieties. An analogous condensation-cyclization sequence of 2,5-dibromophenylene-1,4- diacetic acid with 1-naphthylglyoxylic acid leads to an iso-meric red diimide substituted on the anthracene nucleus. The striking difference in band gaps shows that diimide substitution on the central moiety of diareno[a,h]anthracenes is particularly efficient in inducing long-wavelength absorption. The substitution dependence of the band gap is found to be mainly caused by a variation of the reduction potentials with substituent position, whereas the oxidation potentials are largely substitution-independent.

Mots clés: Chromophores; Donor–acceptor systems; Cyclization; Polycycles; Arenes

Domaines: Chimie organique

Harald Bock, Pauline Carré, Elisabeth A. Hillard, Fabien Durola. Complementary Synthetic Approaches to Elongated Polycyclic Arenes with Regioisomeric Carboxylic Substitution Patterns. European Journal of Organic Chemistry, 2014, 76 (15), pp. 1028-1032. ⟨10.1002/ejoc.201403339⟩. ⟨hal-01117719⟩