Efficient Synthesis of a Novel, Twisted and Stable, Electroluminescent “Twistacene”

Abstract

[reaction: see text] A twistacene, 6,8,15,17-tetraphenyl-1.18,4.5,9.10,13.14-tetrabenzoheptacene (3), was synthesized using a mild and novel bisbenzyne precursor. It was characterized by X-ray crystallography, NMR, UV-vis, and IR spectroscopies, as well as cyclic voltammetry and DFT calculations. The heptacene derivative possesses a nonpropeller twist topology and is unusually stable for a highly conjugated oligoacene. In addition, it is fluorescent, with a quantum efficiency of 15%. Distortion from planarity, mostly due to the phenyl substituents, causes only marginal changes in electronic properties and is beneficial for redox reversibility, which is required for efficient OLED devices.

Synthesis of Extended Triphenylenes by Palladium‐Catalyzed [2+2+2] Cycloaddition of Triphenylynes

“…[1] In recent years, graphite-like [1c, 2] and sterically congested [3] PAHs have attracted special attention because of their unique structures and properties. Interest in triphenylenes has in fact been continuous since certain triphenylene derivatives were found to form discotic liquid crystals.…”

Synthesis, Characterization, and Bipolar Transporting Behavior of a New Twisted Polycyclic Aromatic Hydrocarbon: 1′,4′‐Diphenyl‐naphtho‐(2′.3′:1.2)‐pyrene‐6′‐nitro‐7′‐methyl Carboxylate

“…In fact, an efficient white-light-emitting diode based on a novel "twistacene" has been demonstrated by Wudl and Yang. [15] Herein, we reported the synthesis of a novel twistacene homologue and its bipolar electronic properties.…”

Selective Halogen-Lithium Exchange of 1,2-Dihaloarenes for Successive [2+4] Cycloadditions of Arynes and Isobenzofurans

“…Moreover, it is worth mentioning that 1,2,4,5-tetrabromobenzene (16) nicely worked as a reactive platform [46][47][48][49][50][51], allowing bi-directional cycloadditions in an unsymmetrical manner (Scheme 6). The essential point of this sequential process is using 5-bromo-6-chloro-1,3-diphenylisobenzofuran (9b) to differentiate the reactivity of the two dihalogenated sites in the bis-aryne equivalent 17, which was efficiently obtained by the first [2+4] cycloaddition of dibromobenzyne G and isobenofuran 9b.…”