Organic field-effect transistors based on novel organic semiconductors containing diazaboroles

New pi-conjugated systems containing a diazaborole unit have been prepared by the reaction of the corresponding boronic acids with diamines. They are nearly colorless compounds with electron-donating properties. Single crystal X-ray structure analysis of two compounds revealed their nearly planar structures and unique crystal structures. The OFET devices using the transparent organic semiconductors as an active layer have been successfully fabricated and showed good p-type FET behaviour. The FET device based on the derivative showed high air stability in spite of its high HOMO level. The film structures were investigated with XRD and AFM measurements.