单功能超分支乙烯寡合物.
Thomas Wiedemann1, Gregor Voit, Alexandra Tchernook
1Chair of Chemical Materials Science, Department of Chemistry, University of Konstanz , 78464 Konstanz, Germany.
Journal of the American Chemical Society
|January 24, 2014
概括
催化剂将乙烯转化为超分支的寡合物. 催化剂替代剂控制分支和分子量,其中一种催化剂具有广泛的适用性. 使用,酒精或环氧化物进行功能化是高效和可扩展的.
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:
- 开发高效的乙烯寡合化催化剂对于生产增值材料至关重要.
- 超分支聚合物由于其球状结构和高功能组密度而具有独特的特性.
- 控制聚合物架构和实现选择性功能化是聚合物合成的关键挑战.
研究的目的:
- 为了合成和评估中性 κ(2) N,O-salicylaldiminato Ni(II) 复合物作为乙烯寡合化催化剂.
- 研究催化剂结构对高分支寡合体特性的影响,包括分支密度和分子量.
- 开发可扩展的方法来选择性单一功能化由此产生的超分支寡合体.
主要方法:
- 合成 (II) 盐酸胺复合物与不同的远端替代物 (R = Me, Et, iPr).
- 在不同的压力和温度下使用合成的催化剂进行乙烯氧化反应.
- 现场催化剂系统的准备和评估.
- 通过乙氧化碳化,与乙烯酸乙烯酸的交叉甲基化,然后化和环氧化进行后寡合化功能化.
主要成果:
- 所有的催化剂都产生了高分支的低分子量寡乙烯 (Mn ≈ 1000 g mol-1),具有高生产率.
- 分支密度下降,分子重量增加与更大的替代品 (Me> Et> iPr).
- 催化剂1a-pyr (R=Me) 在广泛的反应条件下表现出强大的性能.
- 一个现场系统与预先形成的催化剂的活性和微观结构相匹配.
- 选择性引入,酒精和环氧化物功能组是有效和可扩展地实现的.
结论:
- 中性salicylaldiminato Ni(II) 复合物是生产高分支基乙烯的有效催化剂.
- 催化剂设计允许调整聚合物结构和特性.
- 单一功能化的可扩展和高效的方法为创建新型功能材料开辟了道路.
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