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

Abstract

The synthesis, property evaluation,a nd 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 ad iazapentacene tetraketone.P dcatalyzed coupling or addition of al ithiuma cetylide gave the precursors that furnish, after furtherr edox reactions, the diazapentacenes as stable crystalline materials. The performance of the tetraphenyl-substituted compoundas n-channel semiconductor was evaluated in organic field effect transistors.

5,7,12,14-Tetraphenyl-Substituted 6,13-Diazapentacenes as Versatile Organic Semiconductors: Characterization in Field Effect Transistors

“…To investigate the influence of nitrogen incorporation into the pentacene scaffold, the oxidation of 2 towards fully πconjugated 3 was targeted. Besides the previously reported oxidation with MnO 2 , 15 compound 2 can be easily oxidized with copper(II) acetate in warm pyridine in quantitative yield (Scheme 1). Nevertheless, the reaction time should not exceed 6 hours, since after that time gradual decomposition is observed, as judged by thin-layer chromatography.…”

“…17 Subsequently, 1 was subjected to a Suzuki cross-coupling reaction with phenylboronic acid under conditions that were slightly modified from those reported previously. 15 The title compound 5,7,12,14-tetraphenyl-6,13-dihydro-6,13-diazapentacene (2) was obtained as a yellow solid after chromatographic purification followed by several recrystallizations from CH 2 Cl 2 /hexanes. The compound was soluble in common organic solvents to give solutions showing intense blue fluorescence.…”

“…We were successful in growing single crystals suitable for X-ray crystallographic analysis for both compounds 2 and 3. 15 The obtained crystal structure for compound 2 occupies the triclinic space group P-1 (Figure 1a, c; see SI for details). The diazapentacene core is planar, resembling the crystal structure of previously reported diazapentacenes.…”

“…11 Recently, Bunz and coworkers reported an updated synthesis of this compound and its subsequent derivatization with acetylides. 15 The first halogenated DAPs were synthesized in 2009 by Tao and coworkers. 5 The authors reported on 5,7,12,14tetrachloro-6,13-diazapentacene (TCDAP) and its reduced dihydro congener (TCDHDAP).…”

“…In the present work, we aimed at tailoring the electronic properties of DAP by lateral arylation. While we recently reported the synthesis and characterization of various 5,7,12,14-tetraaryl-substituted DAPs, 15 we focus herein on the synthesis and characterization of 5,7,12,14-tetraphenylsubstituted DHDAP 2 and DAP 3 (Scheme 1). Through comparison of the characteristics of 2 and 3 with those of the previously reported all-carbon congener 5,7,12,14tetraphenylpentacene (TPP), 18,19 we assessed the impact of the nitrogen incorporation on the molecular properties.…”