Swivel-cruciform oligothiophene dimers

Synthesis and electronic properties of three swivel-cruciform oligothiophene dimers bis(terthiophene) (BT3), bis(pentathiophene) (BT5) and bis(heptathiophene) (BT7)-with increased solubility in organic solvents are reported. We obtained a field-effect mobility of 3.7x10(-5) cm(2) V-1 s(-1) and a current on/off ratio of >10(3) for a solution-processed OFET device with dimer BT5 as p-type semiconductor.