The facile synthesis of a new five-ring-fused pentacene analog with four symmetrically fused thiophene ring units (Dithieno[2,3-d;2',3'-d']benzo[1,2-b;4,5-b']dithiophene, C-n-DTBDT) is presented. After aligning this material from solution, thin films for organic field-effect transistors were obtained, resulting in excellent hole mobilities of up to 1.7 cm(2) V-1 s(-1), and on/off ratio of 10(7).