The syntheses and FET characteristics of perfluoropentacene and perfluorotetracene are described. Both acenes are planar and crystalline materials that adopt p-stack structures with the short interpalnar distances of 3.27 (A) over circle in perfluorotetracene and 3.21 (A) over circle in perfluoropentacene. The oxidation and reduction peak potentials of the perfluorinated acenes shift positively compared with those of the corresponding acenes, suggesting that the HOMO and LUMO energies are diminished by fluorine substituents. Organic field-effect transistors (OFETs) with perfluoropentacene exhibit n-type semiconducting properties with high electron mobility of 0.22 cm(2)/V s.