A review with 71 refs. Important similarities between the new homogeneous catalysts for 1-alkene polymn. based on C2-sym. ansa-metallocenes of the 4th column and their heterogeneous Ziegler-Natta predecessors are unquestionable; in particular, the factors leading to the remarkable enantioselectivity of both catalyst classes have been proved to be strictly analogous. In the case of metallocene catalysts, however, an insidious side reaction of chain epimerization, unnoticed for a relatively long time, can undermine the stereoselectivity of the polymn. process; this recent finding and its mechanistic implications are discussed.
C2-symmetric ansa-metallocene catalysts for propene polymerization: Stereoselectivity and enantioselectivity / Busico, Vincenzo; Cipullo, Roberta; Caporaso, Lucia; Angelini, Giancarlo; Segre Anna, Laura. - In: JOURNAL OF MOLECULAR CATALYSIS. A: CHEMICAL. - ISSN 1381-1169. - STAMPA. - (1998), pp. 53-64.
C2-symmetric ansa-metallocene catalysts for propene polymerization: Stereoselectivity and enantioselectivity
BUSICO, VINCENZO;CIPULLO, ROBERTA;
1998
Abstract
A review with 71 refs. Important similarities between the new homogeneous catalysts for 1-alkene polymn. based on C2-sym. ansa-metallocenes of the 4th column and their heterogeneous Ziegler-Natta predecessors are unquestionable; in particular, the factors leading to the remarkable enantioselectivity of both catalyst classes have been proved to be strictly analogous. In the case of metallocene catalysts, however, an insidious side reaction of chain epimerization, unnoticed for a relatively long time, can undermine the stereoselectivity of the polymn. process; this recent finding and its mechanistic implications are discussed.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
