Five core-cyanated perylene carboxylic diimides end-functionalized with fluorine-containing linear and cyclic substituents have been synthesized and employed in the fabrication of air-stable n-channel organic thin-film field-effect transistors with carrier mobilities up to 0.1 cm(2)/Vs. The relationships between molecular structure, thin-film morphology, substrate temperature during vacuum deposition, transistor performance, and air stability have been investigated. Our experiments led us to conclude that the role of the fluorine functionalization in the air-stable n-channel operation of the transistors is different than previously thought.