Organolanthanide-Catalyzed Synthesis of Phosphine-Terminated Polyethylenes

Abstract

Organolanthanide-mediated hydrophosphination and ethylene polymerization are coupled in a catalytic cycle to produce diphenylphosphine-terminated polyethylenes. The resulting polymers were characterized by 1H, 13C, and 31P NMR, GPC, and DSC and compared spectroscopically to the model compound, 1-eicosyldiphenylphosphine oxide. High activities (107 g polymer/(mol Ln.atm ethylene.h)) and narrow polydispersities were observed in the polymerization/chain transfer process. Polyethylene molecular weights were found to be inversely proportional to diphenylphosphine concentration, supporting a chain transfer mechanism. The present discovery represents the first case in which an electron-rich phosphine functions efficiently as a chain transfer agent in a single-site fn/d0-mediated olefin polymerization process.

Growth of polystyrene films via gas‐phase polymerization with [Pd(CH3CN)4][BF4]2 thin film catalyst

“…These values are very reproducible as long as the styrene vapor pressure is kept constant at the equilibrium vapor pressure at 22 °C. The polydispersity of < 2 is consistent with a single‐site process in which polymers are produced from identical catalytic centers with a fixed rate of chain propagation and chain termination 19, 20…”

Synthesis and crystal structure of dinuclear [(thf)3YCl2{μ-P(H)C6H2-2,4,6-Me3}]2 with seven-coordinate yttrium atoms

“…Phosphanide complexes of d 0 metals (alkali and alkaline earth metals as well as elements of the Sc and Ti groups in their maximal oxidation states) are gaining on importance as catalysts in ethylene [1][2][3] and lactide polymerization [4] and hydrophosphanylation reactions [5][6][7]. Coordination compounds of s-block metals exhibit mainly heteropolar M-P bonds (Lewis acid-base interactions between the cation and the phosphanide anion), whereas compounds of isoelectronic Sc and Y often show unusual coordination spheres.…”

Synthesis, structure, and property of well‐defined polymethylene‐based diblock copolymers by a combination of living polymerization of ylides and atom transfer radical polymerization

“…The design and synthesis of the chain end‐functionalized polyolefin plays an important role in the aforementioned strategies. The chain transfer reactions in the catalytic olefin polymerization using a variety of chain transfer agents, such as the compounds of boron,30, 31 zinc,32 magnesium,33–36 aluminum,37–39 vinyl chloride,40 phosphine,41, 42 silicon,39, 43–45 amine,46 etc., were confirmed to be a good strategy to achieve the end‐functionalized polyolefins. Recently, the living ethylene polymerization using palladium‐diimine complexes with moiety for ATRP was used to prepare highly branched polyethylene‐ b ‐polystyrene (or poly( n ‐butyl acrylate)) diblock copolymers 19.…”