Living alkene polymerization: New methods for the precision synthesis of polyolefins

Unprecedented Comonomer Dependence of the Stereochemistry Control in Pd‐Catalyzed CO/Vinyl Arene Polyketone Synthesis

“…[16,22,29,[44][45][46] For sake of clarity,w ei dentifiedt his species as the cis isomer. This assignment was confirmed by the value of the chemical shift of H 6 ,a th igherf requency with respectt ot he same signal in the free ligand, due to the deshielding effect of the chlorido cis to it. [43,47] The geometryw as unambiguously defined by the correlation peaks between the singlet of Pd-Me and the peaks of the pyrene protons in the NOESY spectrum (see the Supporting Information).…”

“…[1][2][3] Indeed, by tailoring the coordination environment on the metal center,i ts hould be possible to develop single-site catalysts that are able to control the key features of the synthesized macromolecules, such as the mode of main chain linkages, the molecular weight and molecular weightd istribution,t he nature of the end-groups, the comonomer incorporation ands equence along the chain, the linear or branching structure, and the polymers tereochemistry. [4][5][6] The latter is one of the mostf ascinating properties of am acromolecule, since it greatly affects the potentiala pplications of ap olymericm ateriala nd its control is the result of the uniquec haracteristics of single-site catalysts.…”

“…Twop yrene-tagged iminopyridines( N ÀN')w ere used to synthesize neutral and monocationic,p alladium(II) complexes, [Pd(Me)Cl(NÀN')] and [Pd(Me)(MeCN)(NÀN')][PF 6 ]. The monocationicc omplexes generateda ctive catalysts in the CO/vinyl arene copolymerization, leading to polyketonesw ith yields and molecular weight strongly dependento nN -N',w ith the ketiminec atalysts one order of magnitude more productive than the aldimine counterpart.…”

Šezdesetgodišnjica Ziegler-Nattinih katalizatora i stereospecifičnih polimerizacija

“…80 U posljednje se vrijeme postmetalocenski katalizatori primjenjuju i za pripravu određenih polimera i drugih organskih spojeva tzv. "zelenim" sintetskim metodama.…”

Synthesis of a novel branched–hyperbranched diblock polyolefin via chain walking and chain transfer polymerization from ethylene alone

“…[4,5] Usually, living olefin polymerization is an important candidate for preparing block polyolefin via sequential monomers addition and a various of catalysts such as diamine bisphenolate zirconium catalysts, fluorinated bis (phenoxyimine) titanium complexes, palladium, and nickel α-diimine catalysts have been successfully applied in coordinative polymerization of olefin to prepare block polymer. [6,7] However, the inefficiency of living polymerization for one catalyst only produced on polymer chain does not benefit the actual application in industry. In recent 10 years, the tremendous advance of chain shuttling polymerization technology has driven the passion to researchers wishing to prepare novel block polyolefin.…”