Control of coordination polymerization behavior by counter-anionic effects

Research Progress of Iron Catalysts with N,N,N‐tridentate Ligands for Ethylene Polymerization

“…In addition, the cocatalyst also plays a role in removing residual AlMe 3 from the solution. [65][66][67] Bryliakov studied the mechanism of chain transfer and chain end formation in the presence of MMAO and explained the "multisite-like" nature of the catalyst (Figure 7). [68] In the early and middle stages of polymerization, (iBu) 2 AlMe was prone to chain transfer to aluminum, forming low molecular weight of PE.…”

“…Extensive studies can determine that MAO has [À Al(Me)À OÀ ] repeat units and its true structure still being studied and explored due to the complexity of the structure. [83][84][85][86][87][88] In theory, it can affect performance of the catalyst by changing the structure of cocatalysts itself, but the specific structure of MAO is not clear. In future work, clarifying structure of MAO and developing other types of cocatalysts will play a crucial role in the industrial application of the bis(arylimino)pyridine iron catalyst.…”

“…Modification of MAO (MMAO) is designed to address its stability and solubility issues. Extensive studies can determine that MAO has [−Al(Me)−O−] repeat units and its true structure still being studied and explored due to the complexity of the structure [83–88] . In theory, it can affect performance of the catalyst by changing the structure of cocatalysts itself, but the specific structure of MAO is not clear.…”

Cocatalyst effects in Hf-catalysed olefin polymerization: taking well-defined Al–alkyl borate salts into account

“…6–8 First, productivity is strongly dependent on the nature of the cocatalyst, which determines the effectiveness of precatalyst activation and impurity scavenging, and is often involved in side reactions with the active species. 6–12 Furthermore, the cocatalyst usually provides the cationic active species with a counterion, therefore determining ion pairing interactions 6,13–15 that potentially influence catalytic activity 16–24 and stereoselectivity. 25–29…”

Gold-Catalyzed Reactions of Enynals with Alkenes for Synthesis Binaphthyl Derivatives

“…In 1982, Saegusa and co-workers reported a mild generation of cyclic o -QDM intermediates, in which fluoride anion was mixed with [4-(trimethylsilyl)-1,2,3,4-tetrahydronaphth-1-yl] trimethylammonium iodide, and their dimerization reaction lead to binaphthyl derivatives . Meanwhile, controlling polymerization reactions by adjusting the coordination anions of transition metals in the reactions has been reported . Among them, fluoroarylboranes and borates are effective activators to promote polymerization reactions .…”