Synthesis of anthradithiophene containing conjugated polymers via a cross-coupling strategy.

Waseem A Hussain,Kyle N Plunkett

doi:10.1039/d0ra09195b

Waseem A Hussain, Kyle N Plunkett

Open Access

https://doi.org/10.1039/d0ra09195b

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Abstract

New conjugated polymers that incorporate dihexylanthradithiophene (DHADT) in the main chain were prepared by Stille, Sonogashira, and Yamamoto cross-coupling polymerization reactions. The polymerization chemistry is enabled by a soluble 5,11-dibromodihexylanthradithiophene monomer that is capable of cross-coupling reactions. Five readily soluble DHADT containing polymers were prepared and characterized experimentally and computationally. These polymers possess HOMO energies of −5.18 eV to −5.43 eV and LUMO energies of −3.0 eV to −2.82 eV. The notable optical features include broad absorption and band gaps ranging from 1.62 eV to 2.15 eV. Polymers were tested in organic field effect transistors and were found to operate in the p-type regime.

Highlights

Pentacenes and their isoelectronic heteroacene analogues have long been investigated for their applications as optoelectronic materials in organic eld effect transistors, organic photovoltaics and organic light emitting diodes.[1,2,3,4,5]
We report the synthesis of a new series of conjugated copolymers (1–5, Fig. 1) that are accessible through a metal catalyzed cross-coupling reaction at the 5 and 11 positions of dihexylanthradithiophene (DHADT)
The optimized geometries suggest the highest occupied molecular orbitals (HOMO) and lowest unoccupied molecular (LUMO) contours are largely concentrated on the DHADT unit with some delocalization at the adjoining monomers in the ethynylene containing polymers 1 and 2

Summary

Introduction

Pentacenes and their isoelectronic heteroacene analogues have long been investigated for their applications as optoelectronic materials in organic eld effect transistors, organic photovoltaics and organic light emitting diodes.[1,2,3,4,5] Despite pentacenebased materials having high hole carrier mobilities, their poor photostability and solution processability have limited their applications in conjugated polymer materials and have led to the investigation of alternative thiophene-fused polycyclic aromatic hydrocarbons. In relation to pentacene-based polymers,[15,16,17] even fewer conjugated polymers containing the more stable ADT derivatives have been prepared.[18,19,20,21,22] We report the synthesis of a new series of conjugated copolymers (1–5, Fig. 1) that are accessible through a metal catalyzed cross-coupling reaction at the 5 and 11 positions of dihexylanthradithiophene (DHADT).

Results

Conclusion