The solution structure of the zwitterionic complex [Zr(p-CH(2)C(6)H(4)CMe(3))(3)[B(C6F5)(3)(p-CH(2)C(6)H(4)CMe(3))]] and of the ion pair [Zr[m, m'-CH2C6H3(CMe(3))(2)](3)](+)[B(C6F5)(3)[m, m'-CH2C6H3(CMe(3))(2)](-) has been investigated by H-1- and C-13 NMR and compared with that of the zwitterion [Zr(CH(2)Ph)(3)[eta(6)-PhCH(2))B(C6F5)(3)]]. Comparative propene polymerization runs in the presence of the above zirconium complexes have been also performed. The influence of the hydrocarbyl ligands bonded to Zr in the three compounds was negligible, if any. It is concluded that possibly the active species promoting isotactic polymerization could be chiral polynuclear organometallic compounds arising from decomposition of the starting ionic species.
File in questo prodotto:
Non ci sono file associati a questo prodotto.