Trialkylsilylethynyl-functionalized tetraceno[2,3-b]thiophene and anthra[2,3-b]thiophene organic transistors

A series of ethynyl-substituted molecules with the tetraceno[2,3-b]thiophene and anthra[2,3-b]thiophene core have been synthesized. The aim was to investigate the impact of differently bulky side-chain substituents on the packing of the molecule in thin film and hence its thin-film transistor JFT) mobility. Three R groups were used, namely, the tri-isopropyl-, triethyl-, and trimethylsilylethynyl groups. We did not observe a direct correlation between substituent size and TFT mobility. However, the 5,12-bis(triisopropylsilylethynyl)tetraceno[2,3-b]thiophene has a mobility as high as 1.25 cm(2)/V. S, the 5,12bis(trimethylsilylethynyl)tetraceno[2,3-b]thiophene has a mobility of about 0.00616 cm(2)/V. s, while 5, 10bis(triethylsilylethynyl)anthra[2,3-b]thiophene and 5,10-bis(trimetiiylsilylethynyl)anthra[2,3-b]thiophene have a mobility of 10(-4) cm(2)/V . s on phenylsilane- and octadecyltrichlorosilane-treated surfaces respectively.