UV irradiation of Cu-based complexes with aliphatic amine ligands as used in living radical polymerization

Evelina Liarou,Michael Staniforth,James S Town,Arkadios Marathianos,Maria Grypioti,Yongguang Li,Yujing Chang,Spyridon Efstathiou,Ellis Hancox,Alan M Wemyss,Paul Wilson,Bryn A Jones,Mohammed Aljuaid,Vasilios G Stavros,David M Haddleton

doi:10.1016/j.eurpolymj.2019.109388

Evelina Liarou, Michael Staniforth + Show 13 more

Open Access

https://doi.org/10.1016/j.eurpolymj.2019.109388

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Journal: European polymer journal	Publication Date: Nov 27, 2019
Citations: 9	License type: cc-by

Affiliation: University of Warwick

Abstract

The effect UV irradiation on Cu(II)-based complexes with aliphatic amine ligands is investigated. Four aliphatic amines are used as ligands and Cu(II)Br2 as the metal source for the formation of catalyst complexes that can be used for the photoinduced Cu-RDRP of methyl acrylate. Different characterization techniques such as transient electronic absorption spectroscopy (TEAS), ultraviolet–visible (UV–Vis) spectroscopy, electrospray ionization time of flight mass spectrometry (ESI-ToF-MS) and cyclic voltammetry (CV) are applied in order to provide insights into the catalyst behaviour upon photo-irradiation. The excited-state dynamics, the electrochemical behaviour of the Cu(II)/Cu(I) redox couples and the detection of different species upon complexation of the ligand to the metal center (before and after UV irradiation) are further depicted in the quality of the obtained polymers.

Highlights

Controlled/living radical polymerization of vinyl monomers has revolutionized the field of polymer science
The application of different characterization methods and analytical techniques including UV-Vis spectroscopy, ESI-ToF-MS and cyclic voltammetry (CV) give insights into the effect of UV irradiation on the transition metal complex, when different aliphatic amines are employed as ligands (Scheme 1) and Cu(II)Br2 as the metal source
The different complexes were employed for the photoinduced Cumediated Reversible Deactivation Radical Polymerization (Cu-RDRP) of methyl acrylate (MA) with ethyl α-bromoisobutyrate (EBiB) as the initiator, following the ratio [MA]:[EBiB]:[L]:[Cu(II)Br2]=[50]:[1]:[0.02]:[0.12], in 50 % v/v dimethyl sulfoxide (DMSO), under a UV “nail lamp” with broad band emission and λmax~360 nm

Summary

Introduction

Controlled/living radical polymerization of vinyl monomers (methacrylates, acrylates, acrylamides, styrene) has revolutionized the field of polymer science. The application of different characterization methods and analytical techniques including UV-Vis spectroscopy, ESI-ToF-MS and CV give insights into the effect of UV irradiation (broad band λmax~360 nm) on the transition metal complex, when different aliphatic amines are employed as ligands (Scheme 1) and Cu(II)Br2 as the metal source.

Results

Conclusion