A Stable Bis(benzocyclobutadiene)‐Annelated Tetraazapentacene Derivative

Abstract

Biphenylene-2,3-dione is a powerful reagent to build up cyclobutadiene-containing azapolyheterocycles. The target structures are formed in high yields through classical condensation of suitable aromatic diamines with the biphenylenedione. To achieve the title compound, the biphenylenedione is coupled with a diaminobenzothiadiazole derivative. Reductive cleavage of the thiadiazole ring and subsequent condensation with the biphenylenedione gives the title compound in which a central tetraazapentacene is flanked by two benzocyclobutadiene units. This compound is stable despite its extended π-system and its optical features are blueshifted in comparison to those of the symmetrical tetraazapentacene.

Dinaphthobenzo[1,2:4,5]dicyclobutadiene: Antiaromatic and Orthogonally Tunable Electronics and Packing

“…In the past decade, the groups of Swager, Bunz, and Miao, and our group have reported linear acene analogues containing four‐membered rings using different synthetic strategies. However, in all these cases, both crystal structures and calculations indicated strong bond localization exocyclic to the four‐membered rings and diminishing antiaromaticity . To maximize the degree of antiaromaticity while still maintaining stability, we report an alternative design and synthesis of a new family of dinaphthobenzo[1,2:4,5]dicyclobutadiene (DNBDC) structures that feature strong local antiaromaticity of the CBD, independently tunable electronics and crystal packing, and good performance in organic field‐effect transistors (OFETs).…”

Recent Progress in the Usage of Phenazinediamine and Its Analogues as Building Blocks to Construct Large N‐Heteroacenes

“…In 2015, Bunz et al prepared cyclobutadiene‐containing azaacenes of different lengths through condensation between biphenylene‐2,3‐dione 17 and different diamines (Scheme ) . In 2016, the biphenylene‐2,3‐dione was further used as a key starting material to couple with a diaminobenzothidiazole derivative, followed by the reductive cleavage of thiadiazole ring, and then a subsequent condensation with the cleaved product biphenylenedione, producing compound 85 (Scheme ) . The as‐prepared compound tetraazapentacene is stable and the optical absorption is blue‐shifted in relation to that of the symmetrical tetraazapentacene.…”

Mono‐ and Dianion of a Bis(benzobuta)tetraazapentacene Derivative

“…[3] Other groups (Mastalerz, [4] Zhang, [5] Mateo-Alonso, [6] Koert [7] etc.) [13] In this Communication we describe the formation andp roperties of the radical anion and the dianion of ad oubly benzobuta-annelated tetraazapentacene, 1,w hich also features TAPa sas tructural element (Scheme 1, blue structure).Compound 1 [14] was treated with {[18]crown-6}K anthracenide in THF to give consecutively the radical anion and the dianion (reduction potentials of À1.12 and À1.52 V; cyclic voltammetry vs. ferrocene). The breakthrough was Miao's discoveryt hat the symmetrical tetraazapentacene (TAP) displays high n-channel chargem obilities.…”

“…Compound 1 [14] was treated with { [18]crown-6}K anthracenide in THF to give consecutively the radical anion and the dianion (reduction potentials of À1.12 and À1.52 V; cyclic voltammetry vs. ferrocene). The radical anion of 1 is less stable than the TAP radical anion in air,a st he electron affinity of 1 is lower by about 0.6 eV.C alculations (Table 1) of the relative energies of the neutral,a nion and dianion of 1 reveal the anion to be more stable than the neutralf orm by 3.64 eV in THF,a nd the dianion to be more stable than the anion by another 2.8 eV at the DFT/CAM-B3LYP/6-311 ++G** level supporting the lack of disproportionation.…”