Probing chain-end functionalization reactions in living anionic polymerization via matrix-assisted laser desorption ionization time-of-flight mass spectrometry
Probing chain-end functionalization reactions in living anionic polymerization via matrix-assisted laser desorption ionization time-of-flight mass spectrometry
复制标题
DOI：
10.1016/j.ijms.2004.05.014
复制
发表时间：
2004-11-15
影响因子：
1.8
通讯作者：
Wesdemiotis, C
中科院分区：
文献类型：
--
作者：
Arnould, MA;Polce, MJ;Wesdemiotis, C
采用基质辅助激光解吸电离（MALDI）飞行时间（TOF）质谱（MS）对活性阴离子聚合技术制备链端功能聚合物过程中产生的产物进行了研究。研究了聚合后的官能化和官能化引发剂的使用。MALDI-TOF质谱被证明是一种灵敏的探针，用于定性分析机制尚未明确的新型功能化反应中的主要和次要低聚物。该方法对于鉴别次要的、通常是意想不到的分布的终群特别有价值，这些分布可能是其他分析方法无法检测到的。在功能化反应中产生的所有低聚物的完整表征为合成化学家理解相应的机制提供了重要的工具。这种洞察力对于选择替代路线或修改反应条件是必要的。结果表明，MALDl-TOF质谱可以传递官能化过程中引入的链端基团产率的定量信息。从所提出的案例中可以明显看出，聚合后反应可以更好地控制链端功能和分子量，而不是使用有限数量的当前可用的受保护的功能化引发剂进行功能化。(C) 2004 Elsevier B.V.版权所有
Matrix-assisted laser desorption ionization (MALDI) time-of-flight (TOF) mass spectrometry (MS) is applied to examine the products arising upon the preparation of chain-end functional polymers via living anionic polymerization techniques. Both post-polymerization functionalizations as well as the use of functionalized initiators are investigated. MALDI-TOF MS is shown to be a sensitive probe for the qualitative analysis of the major and minor oligomers from novel functionalization reactions whose mechanisms are not yet well established. The method is particularly valuable for the identification of the end groups of the minor, and often unexpected, distributions that may be undetectable by other analytical means. Complete characterization of all oligomers generated during functionalization reactions provides an essential tool to the synthetic chemist for understanding the corresponding mechanisms. This insight is necessary for selecting alternative routes or making modifications to the reaction conditions. It is demonstrated that MALDl-TOF MS can convey quantitative information about the yields of the chain-end groups introduced during functionalization. From the cases presented it is evident that post-polymerization reactions allow for better control of chain-end functionality and molecular weight than functionalization with the limited number of currently available protected functionalized initiators. (C) 2004 Elsevier B.V. All rights reserved.