n-Octyloxyallene homopolymerization and random copolymerization with styrene using catalyst system composed of lanthanide Schiff-base complexes and Al(i-Bu)3

Syndiospecific Polymerization of o-Methoxystyrene and Its Silyloxy or Fluorine-Substituted Derivatives by HNC-Ligated Scandium Catalysts: Synthesis of Ultrahigh-Molecular-Weight Functionalized Polymers

“…The coordination (co)­polymerization of polar olefins to prepare high functional polyolefins having superior surface properties, adhesion properties, and compatibility with other types of materials has always been a challenging and high-profile issue in academia and industry. − The most serious difficulty lies in the fact that the high oxyphilic early transition metal catalysts can be easily poisoned by polar olefins because the stronger Lewis basic heteroatom groups of polar olefins have more preferential coordination ability than the weaker Lewis basic double bond to the strong Lewis acidic metal centers. − Subsequently, the low oxyphilic late transition metal catalysts, which are more tolerant of heteroatom functionalities in the monomer and the polymer, have ascended on the history stage and gradually began to open up new areas for the coordination (co)­polymerization of polar olefins such as polar norbornene, acrylates, vinyl ethers, vinyl acetate, vinyl halides, acrylonitrile, CO, etc. − Recently, a significant breakthrough in the coordination (co)­polymerization of polar olefins has been made by the high oxyphilic rare-earth metal catalysts. − Activated by a catalytically equimolar amount of cocatalyst borate and/or an excess of AlR 3 , rare-earth metal alkyl cations [LLnR] + generated from a series of rare-earth metal dialkyl complexes LLnR 2 L' n (Ln is a rare earth metal center, L is a negative monovalent multi-dentate supporting ligand, R is a negative monovalent alkyl ligand, L' n is a neutral ligand like tetrahydrofuran (THF) solvent molecules with a number in the range of 0–2) exhibit high activities and stereoselectivities in the coordination (co)...…”