Block copolymerizations of higher 1‐olefins with traditional polar monomers using metallocene‐type single component lanthanide initiators

Abstract

Block copolymerizations of 1‐pentene or 1‐hexene with methyl methacrylate or ε‐caprolactone were explored using [Me2Si(2‐SiMe3‐4‐t‐BuMe2SiC5H2)2YH]2 (1) or [Me2Si(2‐SiMe3‐4‐t‐BuC5H2)2SmH]2 (2) as an initiator in toluene or in neat mixtures by the successive additions of monomers in this order. Random copolymerizations of 1‐pentene with 1‐hexene, and random copolymerization of ethylene with 1‐hexene were also performed using 1 as an initiator. Copyright © 2004 Society of Chemical Industry

Organolanthanide-Catalyzed Synthesis of Phosphine-Terminated Polyethylenes. Scope and Mechanism

“…Thus, [Cp‘ 2 LnH] 2 (Cp‘ = η 5 -Me 5 C 5 ) and [Me 2 SiCp‘ ‘ 2 LnH] 2 4 complexes (Cp‘ ‘ = η 5 -Me 4 C 5 ) polymerize ethylene with turnover frequencies exceeding 1800 s -1 at 1.0 atm ethylene pressure and yield polyethylenes with high molecular weights and narrow polydispersities. In addition, organolanthanide complexes effect the homopolymerization of polar monomers as well as mediate the sequential block copolymerization of nonpolar and polar monomers . For example, Yasuda and co-workers used Cp‘ 2 LnR (Ln = Sm, Yb, Lu; R = H, Me) complexes to block copolymerize ethylene with methyl methacrylate (MMA), ethyl methacrylate, δ-valerolactone, and ε-caprolactone 6h.…”

“…In addition, organolanthanide complexes effect the homopolymerization of polar monomers as well as mediate the sequential block copolymerization of nonpolar and polar monomers . For example, Yasuda and co-workers used Cp‘ 2 LnR (Ln = Sm, Yb, Lu; R = H, Me) complexes to block copolymerize ethylene with methyl methacrylate (MMA), ethyl methacrylate, δ-valerolactone, and ε-caprolactone 6h. The block copolymer of polyethylene and poly(MMA) represents a polymer with improved dyeability over nonfunctionalized polyethylene.…”

Polymerization of α-olefins and their copolymerization with ethylene by half-sandwich scandium catalysts with an N-heterocyclic carbene ligand

“…[23][24][25][26][27][28] However, most of these rare-earth metal catalysts usually show low activity or an irreversible chain termination reaction (such as β-H elimination) in α-olefin polymerization, only affording polymers with low molecular weight. [29][30][31][32][33][34][35][36] Recently, by the use of some post-metallocene scandium complexes, [37][38][39] poly(α-olefins) with high molecular weight can be obtained; however, the copolymers of α-olefins and ethylene could not still be obtained. Two cationic half-sandwich scandium complexes (C 5 Me 4 SiMe 3 )Sc (CH 2 SiMe 3 ) 2 (THF) 40 and {fluorenyl-(CH 2 ) 2 -NHC Ph }Sc (CH 2 SiMe 3 ) 2 41 were reported to exhibit a high activity for ethylene and α-olefin copolymerization; however, the molecular weight of the resulting copolymers with slightly higher α-olefin contents was very low because of the irreversible chain termination reaction in α-olefin polymerization.…”

Hydrothermal Synthesis, Structure, Properties of a Novel Supramolecular Complex: [LaCd(bpy)4(NO3)5]

“…These elements show typical electronic properties that potentially give great advantages to the complexes they form with organic ligands. In the trivalent state, they are hard Lewis acids that have interesting applications in catalysis in the fields of polymer synthesis [1][2][3][4][5], organic chemistry [6][7][8][9][10][11][12][13], and bioinorganic chemistry [14][15][16][17][18][19][20].…”