Synthesis of 5,12-Diazapentacenes and Their Properties

Abstract

An efficient synthesis via a precursor route to a new class of linear dialkyldiaminoazapentacenes is reported. The synthetic route involves the coupling of 4-substituted aniline derivatives to 2,5-dibromoterephthalonitrile via Buchwald–Hartwig amination followed by an acid-mediated cyclization to furnish the diazapentacenes. These reactions occur under short reaction times (<2 h), provide high yields (77–99%), and do not require column chromatography for purification. The electrochemical and optical properties of the diazapentacenes were evaluated, and the values indicate that these molecules are promising n-type materials for organic electronic devices. The photostability of these molecules was significantly greater than unsubstituted acenes. Their method of degradation via endoperoxide generation was confirmed by X-ray crystallography and mass spectrometry.

4nπ Stable Multitasking Azapentacene: Acidochromism, Hole Mobility, and Visible Light Photoresponse

“…It has two different types of nitrogen atoms. As the lone pairs of imine nitrogens are orthogonal to the π-system, the first two equivalents of acid would presumably protonate them first . A pair of amine nitrogens would be protonated with the addition of two more equivalents of acid.…”

“…As the lone pairs of imine nitrogens are orthogonal to the π-system, the first two equivalents of acid would presumably protonate them first. 37 A pair of amine nitrogens would be protonated with the addition of two more equivalents of acid. Considering the fact that dissociation of acid in an organic solvent is not quantitative, an appropriate volume of acid was needed.…”

Pd-catalyzed one-pot approach for installation of 9-aminoacridines via Buchwald-Hartwig amination and cycloaromatization

“…35 Despite these impressive advances, finding practical and straightforward synthetic methods to reproduce the 9-aminoacridine basic core molecules would be highly desirable. Encouraged by the numerous bioactivities of 9-aminoacridines and in continuation of our ongoing research on the synthesis of N-heterocycles, [36][37][38][39][40][41][42] we report an efficient method for the synthesis of 9-aminoacridines from the readily available 2-bromobenzonitriles and arylamines via Buchwald-Hartwig coupling reaction followed by acid-mediated cycloaromatization in onepot process. This reaction provides convenient access to various substituted 9-aminoacridines in good to excellent yields with a high tolerance to many functional groups.…”

Switching Pathways of Triplet State Formation by Twisted Intramolecular Charge Transfer

“…Pentacene being an organic semiconductor can be used as a luminescent layer to fabricate various organic optoelectronic devices, including organic light-emitting diodes − and organic solar cells, − as well as field effect transistors. − Moreover, in order to improve the performance such as solubility, charge transport, and efficiency of luminescence, various pentacene derivatives have been constructed; − pentacene doped with nitrogen , is one of them. It will not only enhance the inoxidizability and electron affinity but also degrade energy of the frontier molecular orbital. − The pentacene derivative 5,7-diazapentacene (quinolino­[3,2- b ]­acridine) (Figure a) has not yet been synthesized. With the aim to construct efficient photoelectric materials, several new molecules based on 5,7-diazapentacene were designed and synthesized .…”