An Efficient Synthesis of Tetraazapentacenes

Abstract

Organic electronics on demand? The palladium‐catalyzed coupling of aromatic ortho‐diamines with substituted dichloroquinoxalines furnishes N,N‐dihydrotetraazaacenes, which were oxidized by MnO2 into the corresponding tetraazapentacenes (see structures; N blue, Cl green, Si yellow). The modular synthesis of these acenes allows the introduction of any substituent by choice of the proper quinoxaline derivative.

N,N′-Dihydrotetraazapentacenes (DHTA) in thin film transistors

“…Detailed crystal parameters and .cif-les are listed in the ESI. 24 This packing motif has been observed previously for the analogue 5,14-bis(triisopropylsilylethynyl)-pentacene in which the aromatic backbone also carries the side chains on the second aromatic ring. DHTA-H 2 stacks in isolated, one dimensional columns with a stacking distance of 3.44Å of the aromatic cores of two neighbouring molecules (Fig.…”

“…24 The detailed synthesis procedure as well as the analytical data can be found in the ESI. 24 The detailed synthesis procedure as well as the analytical data can be found in the ESI.…”

“…[17][18][19][20] DHDAP is an oxidation resistant small molecule and can be processed from polar, high boiling solvents such as dimethylformamide (DMF). 24 Here we describe the OFET performance for three substituted, consanguine N,N 0 -dihydrotetraazapentacenes (DHTA-H 2 , DHTA-Cl 2 , DHTA-F 2 ). Also, DHDAP exhibits different polymorphs in its solid state and the correct polymorph must be obtained for an optimum transistor performance.…”

The Position of Nitrogen in N‐Heteropentacenes Matters

“…In comparison with 2 and 4 , their recently reported constitutional isomer, which has pyrazine as the second and third rings of the pentacene backbone and ethynyl groups attached to the fourth ring, has an even lower LUMO energy level at − 4.28 eV as estimated from the reduction potential of − 0.52 V vs. ferrocenium/ ferrocene. [ 11 ] because one pyrazine ring is still not enough to change the molecular packing with hydrogen bonds.…”

Tuning of the stability and energy levels of singlet exciton fission relevant excited states of pentacenes by site-specific substitution

“…Based on these previous investigations, low HOMO and LUMO energies and triplet excited state energies are both favorable for improving the photostability of PAHs though the degradation mechanism is complicated and some details are unknown yet [15][16][17][18]. Therefore, introduction of substituents or heteroatoms to PAHs to change the energies of HOMO and LUMO and the energy of triplet excited state is an useful strategy to change the photostability [19][20][21][22].…”