Ring-opening polymerization of ε-caprolactone catalyzed by ionic hydrogen bond activation with bis-pyridiniums
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چکیده
منابع مشابه
Ring-opening polymerization of ε-caprolactone by lithium piperazinyl-aminephenolate complexes: synthesis, characterization and kinetic studies.
A series of lithium complexes were prepared from 2(N-piperazinyl-N'-methyl)-2-methylene-4-R'-6-R-phenols ([ONN](RR')) and characterized through elemental analysis, (1)H and (13)C{(1)H} NMR spectroscopy, and X-ray crystallography. Treatment of the ligands with n-butyllithium afforded {Li[ONN](RR')}(3) [R = Me, R' = (t)Bu, (1); R = R' = (t)Bu (2); R = R' = (t)Am, (3), (t)Am = C(CH(3))(2)CH(2)CH(3...
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Thiourea (TU)/amine base cocatalysts are commonly employed for well-controlled, highly active "living" organocatalytic ring-opening polymerizations (ROPs) of cyclic esters and carbonates. In this work, several of the most active cocatalyst pairs are shown by 1H NMR binding studies to be highly associated in solution, dominating all other known noncovalent catalyst/reagent interactions during RO...
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Reaction of the pro-ligand α,α,α',α'-tetra(3,5-di-tert-butyl-2-hydroxyphenyl-p-)xylene-para-tetraphenol (p-L(1)H4) with two equivalents of [NbCl5] in refluxing toluene afforded, after work-up, the complex {[NbCl3(NCMe)]2(μ-p-L(1))}·6MeCN (1·6MeCN). When the reaction was conducted in the presence of excess ethanol, the orange complex {[NbCl2(OEt)(NCMe)]2(μ-p-L(1))}·3½MeCN·0.614toluene (2·3½MeCN·...
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Reactions of the tetraphosphine ligand N,N,N',N'-tetra(diphenylphosphanylmethyl)ethylene diamine) (dppeda) or 1,4-N,N,N',N'-tetra(diphenylphosphanylmethyl)benzene diamine (dpppda) with NiCl2, ancillary ligand (C2H5)2NCS2Na (Na(dtc)) and NH4PF6 afforded two binuclear complexes [(dtc)Ni(dppeda)Ni(dtc)](PF6)2 (1) and [(dtc)Ni(dpppda)Ni(dtc)](PF6)2 (2). Compounds 1 and 2 were characterized by eleme...
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Yarrowia lipolytica (YL) is a "non-conventional" yeast that is capable of producing important metabolites. One of the most important products that is secreted by this microorganism is lipase, a ubiquitous enzyme that has considerable industrial potential and can be used as a biocatalyst in the pharmaceutical, food, and environmental industries. In this work, Yarrowia lipolytica lipase (YLL) was...
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ژورنال
عنوان ژورنال: Journal of Polymer Science Part A: Polymer Chemistry
سال: 2016
ISSN: 0887-624X
DOI: 10.1002/pola.28238