Rod-like Tetracene Derivatives.

Efficient and versatile synthetic access to rodlike tetracene derivatives was developed by means of Diels-Alder cycloaddition, halogenation, halogen-metal exchange, and transition metal mediated coupling reactions. Herein, the synthesis and structural, electrical, and charge-transport properties of three of the resulting materials, namely, 2-(tetracen-2-yl)tetracene, 1,4-bis(2-tetracenyl)benzene, and 2,5-bis(2-tetracenyl)thiophene, are presented. Good crystallization behavior on SiO2 substrates, narrowing of the bandgap by 0.2eV, and a decrease of the ionization potential of more than 0.5eV compared to tetracene were observed. Charge-carrier field-effect mobilities on the order of 10(-1)cm(2)V(-1)s(-1), on/off ratios of 10(5), and threshold voltages V-th < 15V were found in thin-film organic field-effect transistors prepared by standard high-vacuum deposition techniques.