The tripodal phosphines MeC(CH2NMe)3P and N(CH2CH2NMe)3P were converted to the corresponding phosphinimines and the corresponding Ti-complexes MeC(CH2NMe)3PNTiCpCl2 (2) and N(CH2CH2NMe)3PNTiCpCl2 (5) were prepared. These species were also alkylated to give the corresponding dimethyl derivatives. Preliminary attempts to utilize these species in the polymerization of ethylene with MAO as the activator resulted in all but negligible activity. An alternative synthetic approach utilizing the bis-phosphinimine (CH2(Me)NPtBu2)2 was developed to prepare (CH2(Me)NP(tBu2)NSiMe3)2 (8), (CH2(Me)NP(tBu2)NH)2 (9) and subsequently [(CH2(Me)NP(tBu2)N)2]Ti(NMe2)2 (10), [(CH2(Me)NP(tBu2)N)2]TiCl2 (11) and [(CH2(Me)NP(tBu2)N)2]TiMe2 (12). For comparison purposes the related species [tBu2(Me2N)PN]2TiCl2 (14) and [tBu2(Me2N)PN]2TiMe2 (15) were also prepared. Compounds (12) and (15), using 2 equiv. of [Ph3C][B(C6F5)4] as the activator, resulted in moderate to good polymerization activities.
将三元膦 MeC( NMe)3P 和 N( NMe)3P 转化为相应的膦
亚胺,并制备出相应的
钛络合物 MeC( NMe)3PNTiCpCl2 (2) 和 N( NMe)3PNTiCpCl2 (5)。这些物质还被烷基化,得到相应的二甲基衍
生物。初步尝试将这些衍
生物用于以 MAO 为活化剂的
乙烯聚合反应,结果发现它们的活性几乎可以忽略不计。我们开发了一种利用
双膦亚胺 (
CH2(Me)NPtBu2)2 的替代合成方法来制备 ( (Me)NP(tBu2)NSiMe3)2 (8)、( (Me)NP(tBu2)NH)2(9),随后又制备了[( (Me)NP(tBu2)N)2]Ti(NMe2)2(10)、[( (Me)NP(tBu2)N)2]TiCl2(11) 和[( (Me)NP(tBu2)N)2]TiMe2(12)。为便于比较,还制备了相关的 [tBu2(Me2N)
PN]2TiCl2 (14) 和 [tBu2(Me2N)
PN]2TiMe2 (15)。化合物 (12) 和 (15) 使用 2 等量的 [Ph3C][B(
C6F5)4] 作为活化剂,具有中等至良好的聚合活性。