Regioisomerically Pure 1,7‐Dibromo‐Substituted Perylene Bisimide Dyes: Efficient Synthesis, Separation, and Characterization

Abstract

1,7‐Dibromo‐substituted perylene bisimides have been obtained in yields of at least 60 % in regioisomerically pure form by treating the commonly used dibromoperylene‐3,4,9,10‐tetracarboxylic dianhydride with 2‐(diethylamino)ethylamine or 2‐(dimethylamino)ethylamine and then separating the 1,7‐isomer from the regioisomeric mixtures by conventional column chromatography and without recrystallization. The individual regioisomers were fully characterized by 1H NMR spectroscopy and HRMS. The signals of the protons located in the aromatic region and neighboring the imide nitrogen atom were utilized to confirm the chemical structures of the isomers. The 1,7‐dibromo isomer obtained with 2‐(dimethylamino)ethylamine in such a convenient and efficient way was further used to prepare 1,7‐disubstituted perylene bisimide derivatives by saponification, amidation, and then bay‐position substitution reactions. These compounds exhibited a significant redshift and broadening of their absorption and emission in optical spectroscopy analysis.

Highly Planarized Naphthalene Diimide–Bifuran Copolymers with Unexpected Charge Transport Performance

“… 11 The synthesis of PDI-based copolymers is challenging due to difficulties in separating isomers. 12 NDI derivatives can be relatively easily incorporated into polymer backbones using various synthetic approaches 6 , 13 , 14 and have thus become prime building blocks in materials for n-channel devices. In 2009, Yan et al reported high electron-mobilities for NDI bithiophene (T2) copolymers, known as PNDI2OD-T2 and herein referred to as PNDIT2, which triggered tremendous interest in NDI-based polymers for use in n-type devices.…”

Building Up Colors: Multilayered Arrays of Peryleneimides on Flat Surfaces and Mesoporous Layers

“…The starting material for the synthesis of 1,7‐substituted PMI 15 was a mixture of mono‐, di‐, and tribromo derivatives of perylene‐3,4,9,10‐tetracarboxylic bis‐anhydride (PTCDA). The mixture obtained by bromination of PTCDA could not be separated owing to its insolubility in organic solvents, and hence, was used directly in the next step . The crude product of esterification was purified by column chromatography on silica gel 60 in CH 2 Cl 2 .…”

“…Compound 6 : Crude product 6 , containing a mixture of mono‐, di‐ and tribromosubstituted derivatives, was obtained from PTCDA (2 g, 5 mmol), according to a procedure reported in the literature, as a dark‐red precipitate (2.54 g, 90 %) and used without further purification owing to its insolubility in organic solvents.…”

Improved Synthesis of Bay‐Monobrominated Perylene Diimides

“…Initial attempts to conduct the imidation with various amines in melted imidazole at high temperature [21,27–30] led to complex mixtures of byproducts. Then, we applied N ‐methylpyrrolidone (NMP)/AcOH solvent system that has been used to obtain dibrominated PDI derivatives [37,38] . Under these conditions, the reaction of 6 with 4‐heptylamine proceeded smoothly to afford the corresponding imide 3 c in 63 % yield.…”

“…Then, we applied N-methylpyrrolidone (NMP)/AcOH solvent system that has been used to obtain dibrominated PDI derivatives. [37,38] Under these conditions, the reaction of 6 with 4-heptylamine proceeded smoothly to afford the corresponding imide 3 c in 63 % yield. This reaction system was also applied to imidation with cyclohexylamine to give the imide 3 f in 60 % yield.…”