通过NacNac--pyridonate调解的e-caprolactone ROP进行调解
Jack W J Hughes1, Dawid J Babula1, Findlay Stowers-Veitch1
1EaStCHEM School of Chemistry, University of Edinburgh, Edinburgh, EH9 3FJ, UK. j.garden@ed.ac.uk.
Dalton transactions (Cambridge, England : 2003)
|November 20, 2023
概括
两种新的复合物与酸连接体有效催化开环聚合 (ROP) 的e-caprolactone没有外部启动器. 皮里多酸连接体上的绝缘散体增强了催化活性,导致高分子量聚烯酸 (PCL).
科学领域:
- 有机金属化学 有机金属化学
- 聚合物化学 聚合物化学
- 催化剂是一种催化剂.
背景情况:
- 复合物与体积大的β-二胺酸 (NacNac) 连接体是已知的聚合催化剂.
- 胺基联结体,如基酸盐,在催化环开聚合 (ROP) 中作为启动群的探索较少.
研究的目的:
- 为了合成和表征新的胺酸复合物.
- 研究它们在 ε-caprolactone (PCL) 的环开放聚合 (ROP) 中的活性.
- 阐明聚合机制和酸盐连接体的作用.
主要方法:
- 新型胺酸复合物的合成和分离.
- 使用1H DOSY NMR光谱法进行溶液状态的表征.
- 使用DFT计算的计算研究.
- 在外部无启动剂条件下的聚合实验.
- 使用MALDI-ToF质谱法进行产品表征.
主要成果:
- 合成了两种新型的复合物,其中包括一个2,6-diisopropylphenyl (Dipp) NacNac连接体和一个2-pyridonate或6-methyl-2-pyridonate amidate连接体.
- 这两种复合物在溶液中都表现出单性行为,并通过单位单金属机制启动ROP.
- 使用两个催化剂在外部无启动剂条件下获得高分子量PCL.
- 皮里多酸连接体 (6-甲基与6-H) 的体量增加增强了催化活性,在1小时内实现了完全的单体转化.
- 在产生的PCL中观察到pyridonate末端组,并检测到循环PCL物种,这表明pyridonate作为离开组的作用.
结论:
- 这些新型胺酸复合物是e-caprolactone外源启动器无ROP的有效催化剂.
- 二酸连接体在聚合的启动和终止步骤中起着至关重要的作用.
- 这些发现代表了使用复合物的酸盐启动ROP的第一个例子.
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