GOALI: NMR Spectroscopy of Methylaluminoxane

该项目由路易斯安那州立大学的Leslie Butler教授和Randall Hall教授及其学生以及Albemarle Corporation的Larry Simert博士完成，在分析和表面化学的支持下，使用基于2H、17O和27Al的核磁共振光谱来表征甲基铝氧烷的活性催化中心，甲基铝氧烷是新一代Ziegler-Natta催化烯烃聚合的助催化剂。27Al位表现出很大的四极相互作用，这需要PI的实验室开发的特殊方法来成功测量核磁共振谱。用密度泛函和分子轨道计算来模拟观察到的四极相互作用，然后将观察到的核磁共振谱与计算的结构进行关联。这个目标项目包含路易斯安那州立大学的PI和Albemarle Corporation的科学家之间的学术和工业合作。Ziegler Natta催化剂用于生产聚合物和塑料的工业重要反应。催化剂涉及分子上发生反应的特定位置。尽管基于一种名为甲基铝氧烷的化合物的Ziegler Natta催化剂得到了广泛的使用，但催化中心的性质尚不清楚。催化剂制备的微小差异会导致催化效率的巨大差异，因此人们对确定该位置的性质很感兴趣。路易斯安那州立大学的Leslie Butler教授和Randall Hall教授及其学生将与Albemarle Corporation的科学家合作，使用独特的光谱技术来确定该地点的性质。Albemarle Corporation是催化材料的生产商和用户。

This project, carried out by Professors Leslie Butler and Randall Hall of Louisiana State University and their students, and Dr. Larry Simeral of the Albemarle Corporation, and supported by Analytical and Surface Chemistry, uses nuclear magnetic resonance spectrometry based on the nuclei 2H, 17O, and 27Al to characterize the active catalytic site of methylaluminoxane, a co-catalyst used in new generation Ziegler-Natta catalysis for olefin polymerization. The 27Al sites exhibit large quadrupolar interactions that require special methods developed in the PI's laboratory for successful measurement of the NMR spectra. Density functional and molecular orbital calculations are used to model the observed quadrupolar interactions, and then the observed NMR spectra are correlated with the calculated structures. This GOALI project contains an academic and industrial collaboration between the PIs at Louisiana State University and scientists at Albemarle Corporation.Ziegler Natta catalysts are used in industrially important reactions that produce polymers and plastics. A catalyst involves a specific site on a molecule where the reaction occurs. Despite the wide use of the Ziegler Natta catalyst based on a compound called methylaluminoxane, the nature of the catalytic site is unknown. Small differences in catalyst preparation lead to large differences in catalytic efficiency, and there is therefore much interest in determining the nature of that site. Professors Leslie Butler and Randall Hall of Louisiana State University and their students will use unique spectroscopic techniques to establish the nature of that site, in collaborative work with scientists at Albemarle Corporation, a producer and user of the catalytic material.