Birhodanines and their sulfur analogues for air-stable n-channel organic transistors

A series of thin-film n-channel organic field-effect transistors based on various birhodanines, 3,3'-dialkyl-5,5'-bithiazolidinylidene-2,2'-dione-4,4'-dithiones (OS-R) and their sulfur analogues, 3,3'-dialkyl-5,5'-bithiazolidinylidene-2,4,2',4'-tetrathiones (SS-R) are studied. The SS-R compounds have tilted stacking crystal structures, whereas the OS-R compounds show basically herringbone structures. The alkyl chain R length and the intermolecular S-S interactions influence the molecular packing to realize excellent long-term air stability in the thin-film transistors.