De Bon Francesco, Fantin Marco, Pereira Vanessa A, Lourenço Bernardino Teresa J, Serra Armenio C, Matyjaszewski Krzysztof, Coelho Jorge F J
Centre for Mechanical Engineering, Materials and Processes (CEMMPRE), ARISE, Department of Chemical Engineering, University of Coimbra, Rua Sílvio Lima, Pólo II, 3030-790, Coimbra, Portugal.
Department of Chemical Sciences, University of Padova, Via Marzolo 1, I-35131, Padova, Italy.
Angew Chem Int Ed Engl. 2024 Jul 15;63(29):e202406484. doi: 10.1002/anie.202406484. Epub 2024 Jun 14.
Alternating current (AC) and pulsed electrolysis are gaining traction in electro(organic) synthesis due to their advantageous characteristics. We employed AC electrolysis in electrochemically mediated Atom Transfer Radical Polymerization (eATRP) to facilitate the regeneration of the activator Cu complex on Cu electrodes. Additionally, Cu served as a slow supplemental activator and reducing agent (SARA ATRP), enabling the activation of alkyl halides and the regeneration of the Cu activator through a comproportionation reaction. We harnessed the distinct properties of Cu dual regeneration, both chemical and electrochemical, by employing sinusoidal, triangular, and square-wave AC electrolysis alongside some of the most active ATRP catalysts available. Compared to linear waveform (DC electrolysis) or SARA ATRP (without electrolysis), pulsed and AC electrolysis facilitated slightly faster and more controlled polymerizations of acrylates. The same AC electrolysis conditions could successfully polymerize eleven different monomers across different mediums, from water to bulk. Moreover, it proved effective across a spectrum of catalyst activity, from low-activity Cu/2,2-bipyridine to highly active Cu complexes with substituted tripodal amine ligands. Chain extension experiments confirmed the high chain-end fidelity of the produced polymers, yielding functional and high molecular-weight block copolymers. SEM analysis indicated the robustness of the Cu electrodes, sustaining at least 15 consecutive polymerizations.
由于其有利特性,交流电(AC)和脉冲电解在电(有机)合成中越来越受到关注。我们在电化学介导的原子转移自由基聚合(eATRP)中采用交流电解,以促进铜电极上活化剂铜配合物的再生。此外,铜作为慢速补充活化剂和还原剂(SARA ATRP),通过歧化反应实现卤代烃的活化和铜活化剂的再生。我们通过采用正弦波、三角波和方波交流电解以及一些活性最高的ATRP催化剂,利用了铜化学和电化学双重再生的独特性质。与线性波形(直流电解)或SARA ATRP(无电解)相比,脉冲和交流电解促进了丙烯酸酯的聚合反应,速度稍快且更可控。相同的交流电解条件能够成功地在从水到本体的不同介质中聚合十一种不同的单体。此外,它在一系列催化剂活性范围内都证明是有效的,从低活性的铜/2,2-联吡啶到具有取代三脚架胺配体的高活性铜配合物。链延伸实验证实了所制备聚合物的高链端保真度,得到了功能性和高分子量的嵌段共聚物。扫描电子显微镜分析表明铜电极具有稳健性,能够维持至少15次连续聚合反应。