解开氨基在原子转移中的作用
Arman Moini Jazani1, Gorkem Yilmaz1, Mitchell Baumer1
1Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, United States.
Journal of the American Chemical Society
|April 2, 2025
概括
多牙胺在铜催化转移基聚合 (ATRP) 中充当电子捐赠者,使得在黑暗中能够控制聚合物合成. 这些氨基酸促进ATRP启动,甚至在剩余空气中提供强大的性能.
科学领域:
- 聚合物化学
- 催化剂
- 有机合成
背景情况:
- 多牙胺是原子转移基聚合 (ATRP) 中铜催化剂的确立配体,并在光化学聚合中作为电子捐赠体.
- 氨基酸在暗色ATRP中的精确机械作用,特别是它们的电子转移途径和结构-活性关系,在很大程度上仍未被探索.
研究的目的:
- 在铜催化ATRP中阐明25种不同的氨基的结构-活性关系.
- 研究氨基,铜复合物和基之间的电子转移机制 (外部球与内部球).
- 在各种条件下证明氨酸作为可控ATRP的强有力的减少剂的实用性.
主要方法:
- 系统地研究各种氨基联体 (L),Br-CuII/L复合物和基化物 (R-Br) 之间的电子转移反应.
- 在黑暗中进行原子转移激素聚合 (ATRP) 实验,使用不同的铜复合物和25种氨基的库.
- 聚合物分散的分析 (Đ) 来评估聚合过程的控制.
主要成果:
- 氨基酸作为电子捐赠体,通过外部球电子转移 (OSET) 减少Br-CuII/L复合体,以产生受控ATRP的CuI/L激活剂.
- 像DBU和TMG这样的特定氨基体表现出更快的还原动力,这表明内部球电子转移 (ISET) 机制.
- 通过使用多余的三级氨基和铜三复合物,即使使用像TEA和DMAE这样的廉价氨基,在室温下在黑暗中成功实现ATRP.
- 多牙胺在高温 (60°C) 上也可以作为直接的R-Br激活剂,其链由R-Br而非氨基基离子启动.
- 氨基酸中介的ATRP在残留空气中表现出强度.
结论:
- 氨基酸是多用途的电子捐赠物和减少剂,对于在黑暗中通过不同的电子转移机制启动和控制ATRP至关重要.
- 选择氨基和铜复合物允许调节ATRP条件,包括使用廉价氨基的室温聚合物.
- 氨基酸是各种ATRP应用的实用和可访问的减少剂,对空气具有耐受性.
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