5,7,12,14-Tetrafunctionalized 6,13-Diazapentacenes

Abstract

The synthesis, property evaluation, and single crystal X-ray structures of four 5,7,12,14-tetrafunctionalized diazapentacenes are presented. The synthesis of these compounds either starts from tetrabromo-N,N-dihydrodiazapentacene or from a diazapentacene tetraketone. Pd-catalyzed coupling or addition of a lithium acetylide gave the precursors that furnish, after further redox reactions, the diazapentacenes as stable crystalline materials. The performance of the tetraphenyl-substituted compound as n-channel semiconductor was evaluated in organic field effect transistors.

Keywords: X-ray diffraction; diazapentacenes; heteroacenes; tetrasubstitution.

Figure 1

Normalized absorption spectra of 3 a–d recorded in dichloromethane (DCM).

Scheme 1

Synthesis of substituted diazapentacenes 3 a–d.

Figure 2

Molecular structures and solid‐state packings of (a) 3 c, (b) 3 d, and (c) 3 b (hydrogen atoms omitted for clarity).