Synthesis and Characterization of Syndiotactic 1,2-Poly(3-methyl-1,3-pentadiene)

Abstract

3-Methyl-1,3-pentadiene was polymerized with the system Fe(bipy) 2 Cl 2 -MAO (bipy ) bipyridine) obtaining a highly stereoregular polymer. The polymer was completely characterized by IR, NMR ( 13 C, 1 H in solution and 13 C in the solid state), DSC, and X-ray techniques and found to have a syndiotactic E-1,2 structure. The crystalline structure of the polymer was also determined, and comparisons are made with other crystalline 1,2-polydienes. The results were compared with those obtained from other dienes (butadiene, isoprene, 2,3-dimethyl-1,3-butadiene) with the same catalyst, which allowed for new data confirming and supporting what already proposed to interpret the diene polymerization mechanism.

Mechanistic insights into regioselective polymerization of 1,3-Dienes catalyzed by a bipyridine-ligated iron complex: A DFT study

“…). This suggests that the 3,4‐insertion is more favorable and therefore is in line with the experimental product of the 3,4‐polyisoperene . To access the origin of the kinetic priorities for the 3,4‐insertion, energy decomposition analyses of the insertion TSs have been carried out (Table ).…”

“…Catalysts based on aliphatic amines were characterized by a low activity and selectivity, whereas catalysts based on iron dichloride and its complexes with bidentate phosphines were practically inactive . Systems based on iron complexes with aromatic bidentate amines were also highly active toward the polymerization of various substituted dienes (e.g., isoprene and 3‐methyl‐1,3‐pentadiene) giving novel polymers with various microstructures . Specifically, the system FeCl 2 (bipy) 2 ‐MAO gives a 3,4‐polymer from isoprene ( IP ) and a 1,2‐polymer rather than 1,4‐polymer from 3‐methyl‐pentadiene ( 3MP ), as shown in Scheme .…”

“…Systems based on iron complexes with aromatic bidentate amines were also highly active toward the polymerization of various substituted dienes (e.g., isoprene and 3‐methyl‐1,3‐pentadiene) giving novel polymers with various microstructures . Specifically, the system FeCl 2 (bipy) 2 ‐MAO gives a 3,4‐polymer from isoprene ( IP ) and a 1,2‐polymer rather than 1,4‐polymer from 3‐methyl‐pentadiene ( 3MP ), as shown in Scheme . Apparently, the methyl substituents of the monomer might affect the observed regioselectivity.…”

Iminoimidazole‐based Co(II) and Fe(II) complexes: Syntheses, characterization, and catalytic behaviors for isoprene polymerization

“…Diverse ancillary ligands, such as N^N^N, N^N^O, N^C^N, N^N, O^P architectures were designed and synthesized. The corresponding Co(II) and Fe(II) complexes were further employed in (co‐)polymerization of dienes . Very recently, Huang and other groups reported Co(II) complexes for isoprene polymerization that offer high activity, precise control over the molecular weight and high cis ‐1,4‐alt‐3,4 microstructures .…”

Iron-based catalysts for conjugated diene polymerization and the polymer properties

“…Ricci等人 [19] 研究了含氮 配体L对FeCl 2 L n /MAO体系催化行为的影响, 发现当 L为芳环结构的双齿含氮化合物时, 催化体系才具有 高活性; L为烷基胺时, 催化剂活性和立构选择性明 显变差, 表明配体的刚性结构对于催化剂活性和立 构选择性起着重要作用. Ricci等人 [22] 以4/MAO催化…”