| 초록 |
Small changes in substituents often lead large difference in molecular conformation, intermolecular packing structure, and film morphology of organic materials, which are key factors determining their charge transport properties in organic field-effect transistor (OFET) devices. In this study, we synthesized a series of 3,7-diphen-2-yl-1,5-dioctyl-1,5-naphthyridine-2,6-dione (NTDP) derivatives bearing various small substituents (OCH3, CH3, F, Cl, and H) in the peripheral phenyl rings to investigate the effects of substituents. Through single crystal analyses, it is revealed that dihedral angles between the bis-lactam core and the peripheral phenyl rings of the derivatives are different depending on the size of substituents, which result in different packing structures. In particular, NTDP-F have ~25° of dihedral angles and co-facial herringbone packing structure, which are favorable to charge transport. Indeed, high hole mobility is achieved up to 0.27 cm2 V-1 s-1 in OFET devices. |
