Regio- and sequence-controlled conjugated topological oligomers and polymers via boronate-tag assisted solution-phase strategy

Chaoran Xu,Yuxuan Du,Xiangcheng Pan,Ning Li,Krzysztof Matyjaszewski,Shicheng Yang,Congze He

doi:10.1038/s41467-021-26186-y

Chaoran Xu, Yuxuan Du + Show 5 more

Open Access

https://doi.org/10.1038/s41467-021-26186-y

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Journal: Nature Communications	Publication Date: Oct 6, 2021
Citations: 30	License type: open-access

Affiliation: Fudan University, Carnegie Mellon University

Abstract

The regulation of polymer topology and the precise control over the monomer sequence is crucial and challenging in polymer science. Herein, we report an efficient solution-phase synthetic strategy to prepare regio- and sequence-controlled conjugated polymers with topological variations via the usage of methyliminodiacetic acid (MIDA) boronates. Based on the solubility of MIDA boronates and their unusual binary affinity for silica gel, the synthesized regio- and sequence-defined conjugated oligomers can be rapidly purified via precipitation or automatic liquid chromatography. These synthesized discrete oligomers can be used for iterative exponential and sequential growth to obtain linear and dendrimer-like star polymers. Moreover, different topological sequence-controlled conjugated polymers are conveniently prepared from these discrete oligomers via condensation polymerization. By investigating the structure-property relationship of these polymers, we find that the optical properties are strongly influenced by the regiochemistry, which may give inspiration to the design of optoelectronic polymeric materials.

Highlights

The regulation of polymer topology and the precise control over the monomer sequence is crucial and challenging in polymer science
The synthesis of discrete oligomers began with the Suzuki–Miyaura coupling reaction between boronic acids and aryl bromides containing methyliminodiacetic acid (MIDA) boronates, and the hydrolysis reaction of MIDA boronates and proceeded to release boronic acid groups
The purification of the MIDA boronate product was achieved via switching the eluent from ethyl ether (Et2O) to ethyl acetate (EA) in automated flash chromatography

Summary

Introduction

The regulation of polymer topology and the precise control over the monomer sequence is crucial and challenging in polymer science. We proposed the iterative synthesis with precise control of the regiochemistry of aromatic monomer for the preparation of regio- and sequence-controlled conjugated polymers with different junctions and topologies, which should be perfect models for studying the relationship between structure and performance. MIDA boronates are employed as the tags in the liquid-phase iterative synthesis and the precursor of boronic acids to prepare regio- and sequence-defined oligomers and sequencecontrolled polymers (Fig. 1b).

Results

Conclusion