Benzodifuroxazinones, a new class of heteroacene molecules for possible applications in organic electronics: Synthesis, electronic properties and crystal structure

A novel class of heteroacene molecules, benzodifuroxazin-4-ones, has been effectively synthesized by means of a thermally activated double cyclization reaction starting from amidic precursors. The new molecules were thermally and optically characterized, revealing an outstanding thermal stability to oxidation and an uncommon enhancement of fluorescent properties in solid state as compared to solution. As shown by single-crystal XRD analysis, the molecules crystallize in a face-to-face (π-stack) arrangement instead of the herringbone structure typical of the most acene derivatives. The electronic properties of both molecules and crystals have been investigated by means of a detailed Density Functional Theory computational analysis: very stable HOMO energies have been calculated and, from the band structure analysis, it is possible to suggest a preferential direction of charge transport along the π-stacking direction. All the reported properties indicate this new class of heteroacene derivatives as interesting candidates for a possible application in organic electronics.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► New chromophores are prepared based on an unprecedented benzodifuroxazione core. ► The chromophores feature an outstanding thermal stability, up to 400 °C in air. ► A peculiar enhancement of photoluminescence in solid state is observed. ► Single crystals XRD analysis revealed a π-stack structure with the molecules arranged face-to-face. ► Band structure analysis suggests a favored charge transport along the π stack direction.