Highly Active Syndiospecific Living Polymerization of Higher 1-Alkene with ansa-Fluorenylamidodimethyltitanium Complex

Zhengguo Cai; Masayoshi Ohmagari; Yuushou Nakayama; Takeshi Shiono

doi:10.1002/marc.200900413

Highly Active Syndiospecific Living Polymerization of Higher 1-Alkene with ansa-Fluorenylamidodimethyltitanium Complex

Macromol Rapid Commun. 2009 Nov 2;30(21):1812-6. doi: 10.1002/marc.200900413. Epub 2009 Sep 1.

Authors

Zhengguo Cai¹, Masayoshi Ohmagari, Yuushou Nakayama, Takeshi Shiono

Affiliation

¹ Department of Applied Chemistry, Graduate School of Engineering, Hiroshima University, Higashi-Hiroshima 739-8527, Japan.

PMID: 21638458
DOI: 10.1002/marc.200900413

Abstract

1-Hexene polymerization was conducted by [t-BuNSiMe(2) (3,6-t-Bu(2) Flu)]TiMe(2) (1) using trialkylaluminum-free modified methylaluminoxane (dMMAO) as a cocatalyst in toluene. The system produced living syndiotactic poly(1-hexene) with high turnover frequency of propagation (TOF, 98 s(-1) ) at 0 °C. The propagation rate was increased linearly against the 1-hexene concentration, which indicates that the first-order dependence of the propagation rate on monomer concentration. Polymerizations of 1-octene, 1-decene and 1-dodecene were also conducted for investigating the effect of chain length of 1-alkene on propagation rate by means of the livingness of this system. The propagation rate decreased according to the chain length until 1-decene but almost unchanged in longer 1-alkene: TOF, 1-octene (62 s(-1) )>1-decene (32 s(-1) ) ≈ 1-dodecene (31 s(-1) ).