Self-directed orientation of molecular columns based on n-type hexaazatrinaphthylenes (HATNAs) for electron transport

Self-organizing n-type hexaazatrinaphthylenes (HATNAs) with various bay-located side chains have been synthesized. The HATNA derivatives are able to form long-range molecular columns with self-directed growth directions. In particular, alkyl-substituted HATNAs showed in-plane molecular columns with axes parallel to substrates, whereas the columnar orientation of the HATNAs with alkylethynyl or alkylthio groups strongly depended on the length of the introduced side chains. Interestingly, the derivative with octylthio chains exhibited out-of-plane molecular columns, in which electron mobility of up to 10(-3)  cm(2)  V(-1)  s(-1) was determined through the time-of-flight technique, highlighting the fact that such molecular columns based on bay-substituted HATNAs are promising n-type semiconductors for device applications.