Synthesis, Photophysical and Electronic Properties of New Red‐to‐NIR Emitting Donor–Acceptor Pyrene Derivatives

Abstract

We synthesized new pyrene derivatives with strong bis(para‐methoxyphenyl)amine donors at the 2,7‐positions and n‐azaacene acceptors at the K‐region of pyrene. The compounds possess a strong intramolecular charge transfer, leading to unusual properties such as emission in the red to NIR region (700 nm), which has not been reported before for monomeric pyrenes. Detailed photophysical studies reveal very long intrinsic lifetimes of >100 ns for the new compounds, which is typical for 2,7‐substituted pyrenes but not for K‐region substituted pyrenes. The incorporation of strong donors and acceptors leads to very low reduction and oxidation potentials, and spectroelectrochemical studies show that the compounds are on the borderline between localized Robin‐Day class‐II and delocalized Robin‐Day class‐III species.

2‐ and 2,7‐Substituted para‐N‐Methylpyridinium Pyrenes: Syntheses, Molecular and Electronic Structures, Photophysical, Electrochemical, and Spectroelectrochemical Properties and Binding to Double‐Stranded (ds) DNA

“…[20,24] It has also been demonstrated by us and others that judicious incorporation of ac ombination of strong p-donors/acceptors at the 2or 2,7-positions of pyrene switches the order of its HOMO/ HOMO-1 andL UMO/LUMO + 1, respectively,w hich in turn greatly influences the photophysical and electrochemical properties. [21,25,26] The localised double bond (C=C) character at the 4-, 5-, 9-, and1 0-positions can be exploited to derivatise pyrene at its K-region. [27,28] Thus, various compounds with substituents at the 4-, 5-, 9-, and10-positionswith interesting photophysicala nd electrochemical properties have recently been reported.…”

“…[23] Moreover, the substituents at the 2-or 2,7-positions do not interact with the HOMO/LUMO, but can interact strongly with the HOMO-1 and LUMO + 1o fp yrene that have non-zero contributions at these positions. [21,[24][25][26] Consequently,t he photophysical properties of pyrene derivatives with substituentsa tt he 2-or 2,7-positions differ significantly from those with substituents at the 1-, 3-, 6-, and 8-positions. This is termedt he "site-effect".…”

Supramolekulare Bindungstaschen in [n]Cyclo‐2,7‐pyrenylenen

“…Der Aufbau des Wandfragments 4 für den Makrozyklus erfolgte durch eine säurekatalysierte Kondensation von 5 mit Ethylenglykol (Abbildung 2 a). [37, 38] Wir entschieden uns für die regioselektive Ir‐katalysierte C‐H‐Borylierung von 4 , um den reaktiven Baustein 3 effizient herzustellen [39] …”

The Aggregation Regularity Effect of Multiarylpyrroles on Their Near‐Infrared Aggregation‐Enhanced Emission Property

“…[13][14][15][16] At present, through the unremitting efforts of scientists, a large number of NIR AIE/AEE dyes have been developed using electron donor-acceptor (D-A) or donor-p-acceptor (D-p-A) strategies. [17][18][19][20] For example, Tang and his co-workers used triphenylamine as ad onor and ap yridine salt derivativea sa na cceptor to synthesize three NIR molecules with targeting effects for synergistic photodynamic therapy,a chieving the 1 + 1 + 1 > 3e ffect. [21] Ding's group reported as eries of AIE dyes in the NIR region using 2-(4-pyridin-4-ylphenyl) acetonitrile as ar eceptor and triphenylamine and benzene as donors and then added tetraphenylethylene (TPE) units in the donorp art to increase the degree of molecular distortion to reduce intermolecular interactions and to increase reactiveo xygen species (ROS) production.…”

“…At present, through the unremitting efforts of scientists, a large number of NIR AIE/AEE dyes have been developed using electron donor‐acceptor (D‐A) or donor‐π‐acceptor ( D ‐π‐A) strategies [17–20] . For example, Tang and his co‐workers used triphenylamine as a donor and a pyridine salt derivative as an acceptor to synthesize three NIR molecules with targeting effects for synergistic photodynamic therapy, achieving the 1+1+1>3 effect [21] .…”