Synthesis and Solid-state Optical Properties of 2,3-Dialkyl- and 2,3,8,9-Tetraalkyltetracenes

We prepared 2,3-dialkyl- and 2,3,8,9-tetraalkyltetracenes by way of Diels-Alder reactions between 1,4-anthraquinones and 3,4-dialkylthiophene-1,1-dioxides and obtained mainly orange and yellow solids, respectively. The differences in optical properties in the solid state were probably due to different intermolecular interactions.