Designing new olefin oligomerization catalysts by tracking unpaired electrons

乙烯齐聚合成高级α-烯烃是化工生产中必不可少的一部分。随着我们远离化石燃料，这条通往附加值更长的碳氢化合物的途径只会变得更加重要。铬基催化剂是这种转变最成熟的催化剂之一。然而，这些都有两个问题。首先，催化剂缺乏选择性，确实有时会使烯烃聚合。其次，由于顺磁性的铬中心，活性催化剂物种的研究具有很高的挑战性。在这个项目中，将开发用于这一重要反应的新型钳形铬催化剂。为了了解催化剂需要如何调整，先进的电子顺磁共振波谱技术将被用来对催化中活性物种的结构进行前所未有的了解。这些数据将建立结构/活性关系，并允许设计一种选择性的、高活性的烯烃齐聚催化剂。

The oligomerization of ethylene to higher alpha olefins is an essential part of chemical manufacturing. This route to value-addedlonger chain hydrocarbons will only become more important as we move away from fossil fuels. Chromium-based catalysts aresome of the most established for this transformation. However these have two issues. Firstly, the catalysts lack selectivity, andindeed sometimes polymerise the olefin. Secondly, the active catalyst species are highly challenging to investigate, due to theparamagnetic chromium centre. In this project new pincer chromium catalysts for this important reaction will be developed. Tounderstand how the catalyst needs to be tuned, advanced electron paramagnetic resonance spectroscopic techniques will beused giving a hitherto unprecedented understanding of the active species' structure in catalysis. This data will establishstructure/activity relationships and allow for the design of a selective, highly-active, catalyst for olefin oligomerization.