Quinoidal naphtho[1,2- b:5,6-b′]dithiophenes for solution-processed n-channel organic field-effect transistors

A series of new quinoidal naphthodithiophenes, 2,7-bis(α,α- dicyanomethylene)-2,7-dihydronaphtho[1,2-b:5,6-b′]dithiophenes, in which all the four fused aromatic rings are incorporated into the quinoidal system, were synthesized and evaluated as an n-channel organic semiconductor. Solution-processed field-effect transistors exhibited typical n-channel transistor characteristics with the mobility as high as 0.1 cm² V^-1 s^-1, which is higher by more than 1 order of magnitude than those reported for isomeric quinoidal naphthodithiophenes having a naphthoquinoidal structure.