Synthesis of Pechmann derivatives for potential application in organic electronics or photovoltaics

The synthesis of the (E)-3,3'-bifuranylidene-2,2'-dione heterocyclic system has been first published in 1882 by Von Pechmann. Recently promising optical and electronic properties have been demonstrated in some Pechman derivatives and this fact has stimulated further studies concerning the preparation of such scaffold and its incorporation into longer conjugated systems, which might have a potential interest for organic electronics. In this work, the preparation and spectroscopic characterization of some symmetrical small molecules containing the so-called Pechmann lactone and featuring an extended conjugation, are reported. The absorption and emission spectra of the new molecules obtained have been recorded in solution and clearly show how the photophisical properties can be modulated by a proper choice of the (hetero)aromatic terminal groups. All the compounds prepared in this study have interesting optical properties and could find application as semiconductors in organic electronics or photovoltaics.