A Series of Soluble Thieno-Fused Coronene Nanoribbons of Precise Lengths

Abstract

Among graphene nanoribbons (GNRs), reports on coronene-based GNRs were very rare, despite the unique optoelectronic properties of coronene. Herein, the synthesis of a series of structurally precise and soluble thieno-fused coronene nanoribbons (CR-1 to CR-4) with up to four coronene units connected through benzene rings along their K-regions is described by two different synthetic approaches. Due to the triptycene end-caps, all CRs are soluble, allowing the characterization of such structures in solution and the study of the length-dependent photophysical properties that are supported by theoretical calculations.

Two Dimensional Triptycene End‐Capping and Its Influence on the Self‐Assembly of Quinoxalinophenanthrophenazines†

“…[ 15 ] Taking advantage of the beneficial combination of the solubilizing effect and the crystallization behavior, a pyrene‐ fused N ‐heteroacene with eleven rectilinearly annulated aromatic rings and two triptycenyl end‐caps was introduced, [ 17 ] showing a well‐resolved 1 H NMR‐spectrum at 298 K in CDCl 3 while the similar π‐backbone with long dodecyloxy groups led to broad peaks in deuterated oDCB, even at elevated temperatures (373 K). [ 13 ] The general concept of using two triptycene end‐caps to substantially increase solubility [ 18 ] was further applied to hexabenzoovalenes, [ 19‐21 ] benzo‐ and naphtothienobenzothiophenes, [ 22 ] chiral bis(diazadibenzoanthracenes), [ 23 ] indigo dyes, [ 24 ] benzo‐fused perylene oligomers, [ 25 ] thieno‐fused coronene nanoribbons [ 26 ] or a nanobelt based cycloiptycene. [ 27 ] However, when only one triptycene end‐cap is attached to QPPs, precise π‐dimerization occurred in the solid state, mostly independent from further substituents at the backbone.…”

Azaarenes: 13 Ringe in einer Reihe durch Cyclopentanellierung

“…Die Anzahl der Clar‐Sextette erhöht sich durch Kombination von Aceneinheiten mit anderen kleinen Kohlenwasserstoffen, wie Perylen, 14, 15] Corannulen, [15] Pyren, [5a, 13h,k, 16] Phenanthren, [13b] para‐ Benzochinon [17] und seine Knoevenagel‐Derivate (Abbildung 1, A ) [18] . Synthesezugänge umfassen Kondensationsreaktionen, besonders für Stickstoff‐substituierte Nanokohlenstoffe wie ( B ), [23a, 29] Buchwald–Hartwig‐Kupplungen ( C ), [15] Suzuki‐Kupplungen, Friedel–Crafts‐Ringschlüsse ( D ) [28] sowie Cava‐Reaktionen ( A ). Alternativ spalten Cycloreversionen Schmetterlingsdimere [19] oder thermo‐ oder photolabile Gruppen [20] um das konjugierte π‐System im letzten Syntheseschritt zu generieren.…”

Synthesis, Photoswitching Behavior and Nonlinear Optical Properties of Substituted Tribenzo[a,d,g]coronene

“…The construction of structurally defined polycyclic aromatic hydrocarbons (PAHs) has attracted substantial interest during the past several decades because such molecules can be usually seen as a segmental model for defects of graphene possessing interesting physical properties and can be used in organic electronics including laser, photodetectors, organic light emitting diodes, organic field effect transistors and organic solar cells [ 1 , 2 , 3 , 4 ]. Among them, curved π-conjugated derivatives provide us with more room to deepen our understanding of the anomalous hexagon arrays, which can be obtained through the implementation of armchair, cove, fjord regions, and the embedment of four-, five- seven- and eight-membered rings [ 5 , 6 , 7 , 8 ]. Undoubtedly, the edge and size can affect the optoelectronic and magnetic properties to a great extent, leading to different aromaticity, energy levels and band gaps.…”