Cytotoxic Titanium Salan Complexes: Surprising Interaction of Salan and Alkoxy Ligands
作者:Timo A. Immel、Ulrich Groth、Thomas Huhn
DOI:10.1002/chem.200902312
日期:——
The synthesis, biochemical evaluation, and hydrolysis studies of a wide selection of alkyl‐ and halogen‐substitutedtitanium salan alkoxides are presented herein. A systematic change in the employed alkoxides revealed that both the bulk of the salan ligands and the steric demand of the labile ligands are of great importance for the obtained biological activity. Surprisingly, these two factors are not
Structure/Properties Relationship for Bis(phenoxyamine)Zr(IV)-Based Olefin Polymerization Catalysts: A Simple DFT Model To Predict Catalytic Activity
作者:Gianluca Ciancaleoni、Natascia Fraldi、Roberta Cipullo、Vincenzo Busico、Alceo Macchioni、Peter H. M. Budzelaar
DOI:10.1021/ma300343c
日期:2012.5.22
The productivity of a number of bis(phenoxyamine)Zr(IV)-based catalysts (bis(phenoxyamine) = N,N′-bis(3-R1-5-R2-2-O-C6H2CH2)-N,N′-(R3)2-(NCH2CH2N)) in ethene and propene polymerization was evaluated for different R1/R2/R3 combinations. In previous studies on this class we demonstrated that the cations that form upon precatalyst activation (e.g., by methylalumoxane) adopt a “dormant” mer-mer geometry
多种基于双(苯氧基胺)Zr(IV)的催化剂的生产率(双(苯氧基胺)= N,N'-双(3-R 1 -5-R 2 -2-OC 6 H 2 CH 2)-对于不同的R 1 / R 2 / R 3组合,评估了乙烯和丙烯聚合中的N,N '-(R 3)2-(NCH 2 CH 2 N))。在对这一类的以前的研究,我们证明了阳离子即在前段催化剂活化(例如,由甲基铝氧烷)的形式采取“休眠”滨海聚体的几何形状,和吸热异构化到活动fac-fac几何形状是催化循环的必要第一步。因此,我们报告了催化剂活性与DFT计算的活性态和休眠态之间的能量差ΔE i之间的明显相关性。只有在对离子对进行计算时,相关性才成立,这并不像可能出现的那样明显,因为这些系统中的阴离子不在催化剂前沿。该发现提供了相对简单且快速的方法来预测相同类别的新催化剂的活性。