Synthesis of Conjugated Carbazole Trimers and Pentamers by Suzuki Coupling

Abstract

A series of N‐alkylcarbazol‐3,6‐diyl trimers and pentamers has been synthesized by stepwise Suzuki coupling. The trimers with isopropyl and longer alkyl substituents at the nitrogen atom and all the pentamers form stable glasses with glass transition temperatures varying from 30 to 148 °C for the trimers and 65 to 104 °C for the pentamers. The ionization potential of the N‐alkylcarbazol‐3,6‐diyl trimers is 5.25 eV and 5.20 eV for the pentamers. N‐alkylcarbazol‐3,6‐diyl compounds typically exhibit hole‐drift mobilities in the range of 10−4–10−6 cm2 · V−1 · s−1. The highest hole‐drift mobility observed in an amorphous film of N‐octylcarbazol‐3,6‐diyl pentamer reached 10−3 cm2 · V−1 · s−1 at an applied electric field of 8.1 × 105 V · cm−1. magnified image

Form or function? Part 1. Subjective cosmetic and functional correlates of quality of life in women treated with breast-conserving surgical procedures and radiotherapy

“…In PNPC8, a similar hole mobility µ FET of 7 × 10 −5 cm 2 · V −1 · s −1 in the saturation regime with an on/off ratio of up to 10 4 was extracted for the devices. One motivation to tune the device setup and purify the polymers further are the high mobilities in the range of 10 −3 cm 2 · V −1 · s −1 , which were measured in TOF experiments by Paliulis et al10 on pentameric carbazole molecules. Nevertheless, the integration of such materials in an OFET device is not trivial and needs more device optimization to reach such high values as those in TOF experiments.…”

“…The low cost starting material (9H‐carbazole), the chemical and environmental stability of the resulting fully aromatic oligomers and polymers, and the ease of chemical substitution at the 9‐nitrogen atom are, hereby, important features. Substitution in the 9‐position allows for the introduction of a wide range of functional groups permitting an improved solubility and a tuning of the electronic and optical properties 1–10. For application as p‐type organic semiconductor in printed organic field effect transistor (OFET) devices, material properties such as sufficient charge carrier mobility, high thermal stability, non‐crystalline or amorphous solid state morphology (to circumvent thermal post‐processing treatments) and electrochemical stability constitute some of the necessary requirements 11…”

Synthesis, characterization, photophysics and electrophosphorescent applications of phosphorescent platinum cyclometalated complexes with 9-arylcarbazole moieties

“…The X group spans from H to F and OMe. Pyridyl-substituted 9-phenyl-3-(pyridin-2-yl)carbazoles L 4 -L 6 were synthesized from palladium-catalyzed Suzuki cross coupling [44][45][46][47] of commercially available 2-chloro-5-trifluoromethylpyridine, 2-chloro-5-fluoropyridine or 2-chloro-4-methylpyridine with 9-phenylcarbazole-3-boronic acid, respectively [48,49]. For L 7 -L 8 , the N-arylation of carbazole was carried out by the Ullmann condensation of carbazole with 1-bromo-4-iodobenzene and 2-bromo-7-iodo-9,9-diethylfluorene [50] to give 9-(4-bromophenyl)carbazole and 9-(7-bromo-9,9-diethylfluoren-2-yl)carbazole which can then undergo Stille-coupling protocol with 2-(tri-n-butylstannyl)pyridine to afford L 7 and L 8 which carries a cyclometalating 2-phenylpyridine site for coordination with metal groups.…”

Copper(II) and Zinc(II) Complexes with a Photoactive Bridging Ligand Based on Carbazole: Synthesis, Structures, Electronic and Magnetic Properties

“…[5,6] N-aryl-substituted carbazoles constitute a subclass of triphenylamines, which have been extensively studied. The design of organic light-emitting diodes, [7] photovoltaic elements, [8] and other organic electronic devices [6,9] are only three fields of interest for this type of molecule.…”

“…[5,6] N-aryl-substituted carbazoles constitute a subclass of triphenylamines, which have been extensively studied. The design of organic light-emitting diodes, [7] photovoltaic elements, [8] and other organic electronic devices [6,9] are only three fields of interest for this type of molecule. In addition, aryl-substituted carbazoles have been studied due to their unusual fluorescence behavior, which has been discussed in terms of twisted intramolecular charge transfer [10] and recently by other mechanisms.…”