Poly[(arylene ethynylene)-alt-(arylene vinylene)]s Based on Anthanthrone and Its Derivatives: Synthesis and Photophysical, Electrochemical, Electroluminescent, and Photovoltaic Properties.

Suru Vivian John,Daniel Ayuk Mbi Egbe,Jean-Benoit Giguère,Jean-François Morin,Emmanuel Iwuoha,Antoine Lafleur-Lambert,Aleš Růžička,Věra Cimrová,Christoph Ulbricht,Veronika Pokorná

doi:10.1021/acs.macromol.7b02136

Abstract

Anthanthrone and its derivatives are large polycyclic aromatic compounds (PACs) that pose a number of challenges for incorporation into the structure of soluble conjugated polymers. For the first time, this group of PACs was employed as the building blocks for the synthesis of copolymers (P1–P5) based on poly[(arylene ethynylene)-alt-(arylene vinylene)]s backbone (−Ph–C≡C–Anth–C≡C–Ph–CH=CH–Ph–CH=CH−)n. During the synthesis of P1–P5, different alkyloxy side chains were incorporated in order to tune the properties of the polymers. Of the copolymer series only P1 (containing anthanthrone and branched 2-ethylhexyloxy side chains on phenylenes), P2 and P3 (for which the anthanthrones containing carbonyl groups were converted to anthanthrene containing alkyloxy substituents) were soluble. The photophysical, electrochemical, electroluminescent and photovoltaic properties of P1–P3 are reported, compared and discussed with respect to the effects of side chains.

Highlights

Polycyclic aromatic compounds (PACs) have attracted considerable attention as materials with potential applications in supramolecular electronics[1−3] and are becoming increasingly popular for optoelectronic applications.[4−9] The extensive conjugated π-systems of PACs facilitate electron delocalization, while the rigid flat geometry enables them to stack in wellorganized arrays for strong π-stacking interactions
The extension of the effective conjugation of the polymers can be used to overcome this drawback,[24−26] it is often accompanied by a significant decrease in solubility, which may hinder their processing into thin films for photovoltaic applications
Optimization of several parameters such as the morphology, variation of the mutual component ratio in blends and utilization of more appropriate device architecture could further improve the or photovoltaic (OPV) devices.[63−68] We have recently shown that fullerene aggregation occurs in the blend layers, which can negatively influence the device performance.[69]

Summary

Introduction

Polycyclic aromatic compounds (PACs) have attracted considerable attention as materials with potential applications in supramolecular electronics[1−3] and are becoming increasingly popular for optoelectronic applications.[4−9] The extensive conjugated π-systems of PACs facilitate electron delocalization, while the rigid flat geometry enables them to stack in wellorganized arrays for strong π-stacking interactions. The πconjugated systems influence the tuning of the optoelectronic properties, while the flat geometry enables good light emitting properties and intermolecular charge transport.[10−15] These combined features make PACs appealing building blocks for the preparation of semiconducting polymers. A comparatively low number of conjugated polymers incorporating large PACs building blocks have been reported so far.[16−24]. Large hexabenzocoronene PAC was incorporated in the main chain of conjugated polymers.[27] These materials, were insoluble in common organic solvents and difficult to process. Its rigidity coupled with its large and flat π surface hinders good solubility in common organic solvents. The synthesis and characterization of the first series of soluble conjugated polymers based on anthanthrone derivative (anthanthrene)[29] and 4,10-bis(thiophen-2-yl)anthanthrone (TANT) were reported.[30]

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