STRUCTURE AND REACTIVITY OF BIS(PENTAMETHYLCYCLOPENTADIENYL)(ETHYLENE)TITANIUM(II), A SIMPLE OLEFIN ADDUCT OF TITANIUM
STRUCTURE AND REACTIVITY OF BIS(PENTAMETHYLCYCLOPENTADIENYL)(ETHYLENE)TITANIUM(II), A SIMPLE OLEFIN ADDUCT OF TITANIUM
复制标题
DOI：
10.1021/ja00343a012
复制
发表时间：
1983-01-01
影响因子：
15
通讯作者：
BERCAW, JE
中科院分区：
文献类型：
--
作者：
COHEN, SA;AUBURN, PR;BERCAW, JE
C5Me5)2Ti(？J-C2H4)]。这种络合物代表了第一个可分离的钛的乙烯加合物的例子。钛-烯烃络合物被广泛用作Ziegler-Natta烯烃聚合的关键中间体。而(7J-C5Me5)2Ti(？；-C2H4)用乙烯处理几个月后只有少量的聚合物，(n-C5Me5)2Ti(7)-C2H4参与了一系列化学计量和催化反应。其中包括乙烯的催化转化为丁二烯和乙烷，以及烯烃的催化异构化。自从首次报道TiCl3和三烷基铝的混合物是乙烯聚合和a-烯烃高有序聚合物的形成的活性催化剂以来，有机钛化学一直是一个非常活跃的研究领域。2、3鉴于烯烃聚合的科学和商业重要性，人们已致力于阐明齐格勒-纳塔型催化反应的机理(S)。尽管已经形成了许多基本上不同的机制，4通常认为反应是通过烯烃与烷基钛络合物配位发生的，然后经过烯烃插入(或烷基迁移)以生成
C5Me5) 2Ti (? j-C2H4)] are reported. This complex represents the first example of an isolable ethylene adduct of titanium. Titanium-olefin complexes have been widely invoked as key intermediates in Ziegler-Natta olefin polymerization schemes. Whereas treatment of (7j-C5Me5) 2Ti (?;-C2H4) with ethylene leads to only traces of polymer aftermonths,(n-C5Me5) 2Ti (7)-C2H4) participates in a range of stoichiometricand catalytic reactions. These include the catalytic conversion of ethylene specifically to butadiene and ethane and the catalytic isomerization of alkenes.Organotitanium chemistry has been a very active area of re-search since the first reports that mixtures of TiCl3 and tri-alkylaluminum are active catalysts for the polymerization of ethylene and the formationof highly ordered polymers of the a-olefins. 2, 3 In view of the scientific and commercial importance of olefin polymerization, significant effort has been directed toward the elucidation of the mechanism (s) of Ziegler-Natta-type ca-talysis. Although a number of substantially different mechanisms have been formulated, 4 the reaction is generally believed to occur via coordination of an olefin to an alkyltitanium complex, which then undergoes olefin insertion (or alkyl migration) to generate