The new thf supported cations, [Salen(tBu)Al(thf)2]+ (2), [Salpen(tBu)Al(thf)2]+ (3), [Salben(tBu)Al(thf)2]+ (4) [Salophen(tBu)Al(thf)2]+ (5) and [Salomphen(tBu)Al(thf)2]+ (6), with BPh4− as the counter anion, have been prepared from salt elimination reactions with the respective Salen(tBu)AlCl reagent, including one that is new, Salben(tBu)AlCl (1). The cations were observed to polymerize propylene oxide. Based upon the results of experimental and theoretical work the mechanism appears to be
one in which a carbocation is the propagating species although the PDI values are remarkably low, ≈1.2 in some cases. All of the potential catalysts were characterized spectroscopically and, in the case of 3, by X-ray crystallography.
新的 thf 支持的阳离子,[Salen(tBu)Al(thf)2]+ (2)、[Salpen(tBu)Al(thf)2]+ (3)、[Salben(tBu)Al(thf)2]+ (4) [Salophen(tBu)Al(thf)2]+ (5) 和 [Salomphen(tBu)Al(thf)2]+ (6),以 BPh4− 作为抗衡阴离子,通过盐消除反应制备使用相应的 Salen(tBu)AlCl 试剂,包括一种新试剂 Salben(tBu)AlCl (1)。观察到阳离子聚合环
氧丙烷。根据实验和理论工作的结果,该机制似乎是
其中
碳正离子是繁殖物种,尽管 PDI 值非常低,在某些情况下约为 1.2。所有潜在的
催化剂都通过光谱学进行了表征,对于 3,还通过 X 射线晶体学进行了表征。