Ethylene/1‐pentene copolymers synthesized using the metaloxycarbene complex catalyst system [(CO)₅W=C(Me)OZr(Cp)₂Cl]/MAO

Abstract

Ethylene/1-pentene copolymers were prepared using a [(CO) 5 Wϭ C(Me)OZr(Cp) 2 Cl] (1)/MAO catalyst system. 1-Pentene incorporation in the copolymer was monitored using 13 C-NMR spectroscopic methods. The weight average molecular weights (M w ) of the copolymers were between 142,000 and 629,000 g/mol, with polydispersity indexes (PDIs) ranging from Ϸ 2 to 90, as analyzed by size exclusion chromatography (SEC). Melting and crystallization temperatures, determined using differential scanning calorimetry (DSC) and crystallization analysis fractionation (CRYSTAF), decreased linearly as the amount of 1-pentene in the copolymer increased. SEC-FTIR revealed that the 1-pentene is predominantly incorporated in the low molecular weight fraction.

On the multimodality of preparative TREF fractionation as detected by advanced analytical methods

“…The signal assignments as shown in Fig. 1c are based on Randall [19] and others [20][21][22]. The copolymer compositions were calculated from the intensities of the branch carbon (br) and the backbone carbons (α, β, γ, δ, ε).…”

Pentacarbonyl-2κ5C-chlorido-1κCl-bis[1(η5)-cyclopentadienyl](μ-1-oxidoethylene-1:2κ2O:C)chromium(0)zirconium(IV)

“…Since Cp 2 TiCl 2 was shown to polymerize ethylene when activated by methylaluminoxane, MAO (Sinn et al, 1980), derivatives of this compound have been synthesized where a Cl ligand was replaced by a monodentate anionic Fischertype carbene ligand (Barluenga and Fañanás, 2000). We have shown that zirconocene equivalents of this family of homogeneous catalysts, Cp 2 Zr(Cl)OC(R)M(CO) 5 (where M = W or Cr), catalyze the oligomerization of 1-pentene, as well as the copolymerization of ethene and 1-pentene, in the presence of MAO (Luruli et al, 2004;Luruli et al, 2006). Herein we report the crystal structure of the title zirconocene complex, (I).…”

“…For related literature regarding catalytic data of the title compound, see: Sinn et al (1980); Luruli et al (2004Luruli et al ( , 2006. For other cases of anionic Fischer-type carbenes being used as monodentate ligands, see: Barluenga & Fañ aná s (2000).…”

Pentacarbonyl-2κ5C-chlorido-1κCl-bis[1(η5)-cyclopentadienyl][μ2-oxido(methyl)methylene-1:2κ2O:C]tungsten(0)zirconium(IV)

“…For related literature regarding catalytic data of the title compound, see: Sinn et al (1980);Brü ll et al (2001); Luruli et al (2004Luruli et al ( , 2006. For comparable structures, see: Erker et al (1989); Wolczanski et al (1983); Esterhuysen et al (2008).…”

“…In our ongoing studies into finding improved catalysts for the oligomerization of αolefins we have studied zirconocene equivalents to (I) where we replaced one of the Cl ligands with a number of different ligands (Brüll et al, 2001). In particular, the use of a tungsten-carbene moiety as a ligand, (II), has been proven to result in an effective catalyst for the oligomerization of 1-pentene, as well as the copolymerization of ethene and 1-pentene, in the presence of MAO (Luruli et al, 2004;Luruli et al, 2006). Herein we report the crystal structure of the title zirconocene complex, (II).…”