Synthesis and catalytic applications of C1 symmetric group 4 ansa-metallocene complexes
2006; Elsevier BV; Volume: 264; Issue: 1-2 Linguagem: Inglês
10.1016/j.molcata.2006.09.011
ISSN1873-314X
AutoresSantiago Gómez‐Ruiz, Sanjiv Prashar, Luis F. Sánchez‐Barba, Dorian Polo‐Cerón, Mariano Fajardo, Antonío Antiñolo, Antonío Otero, M.A. Maestro, C.J. Pastor,
Tópico(s)Synthetic Organic Chemistry Methods
ResumoThe group 4 ansa-metallocene complexes with chiral substituent bearing cyclopentadienyl ligands, [M{Me2Si(η5-C5Me4)(η5-C5H3{CHRR′})}Cl2] (R = Pri, R′ = Me (9); R = Pri, R′ = Ph (10); R = But, R′ = Me (11); R = But, R′ = Ph (12); M = Zr (a), Hf (b)), were synthesized by the reaction of the dilithium compounds, Li2{Me2Si(C5Me4)(C5H3{CHRR′})} (R = Pri, R′ = Me (5); R = Pri, R′ = Ph (6); R = But, R′ = Me (7); R = But, R′ = Ph (8)), with the tetrachloride salts of the transition metal. The molecular structures of 11a and 12a have been determined by single-crystal X-ray diffraction studies. The catalytic behaviour of 9–12 in the polymerization of ethylene and propylene has been studied. Isotactic polypropylene with [mmmm] pentads of the order of 60% were obtained with the C1 symmetric ansa-zirconocene catalysts.
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