نتایج جستجو برای: metallocene catalyst
تعداد نتایج: 44388 فیلتر نتایج به سال:
in this thesis, we exploit a simple and suitable method for immobilization of copper(ii) complex of 4?-phenyl-terpyridine on activated multi-walled carbon nanotubes [amwcnts-o-cu(ii)-phtpy]. this nanostructure was characterized by various physico-chemical techniques. to ensure the efficiency and fidelity of copper species, the implementation of three-component strategies in click-chemistry all...
9 Titanocene and zirconocene complexes with a phenyl or I-naphthyl substituent in one ,B-position of each Cs-ring ligand and with an interannular tetramethylethanoor dimethylsilano-bridge have been prepared. Racemic complex isomers, which are formed together with varying amounts of their meso isomers, were separated from the latter and characterised by lH NMR spectroscopy and X-ray crystallogra...
Two grades of metallocene-catalysed LLDPE and one grade of low-density polyethylene (LDPE) have been silane grafted and crosslinked by contact with water and their performance has been compared and evaluated. The effects of vinytrimethoxysilane (VTMOS) levels on the degree of crosslinking for each grade were also studied. It was found that increasing level of silane increases the degree of cros...
Functional group transformations at the group 4 metallocene framework have been demonstrated, which have provided relatively straightforward access to otherwise synthetically challenging derivatives. The pendant nitrile group in Ti and Zr metallocene complexes of the type [(η(5)-C5Me5)(η(5)-C5H4CMe2CH2CN)MCl2] was converted into an intramolecularly bound ketimido moiety by alkylation, which too...
We have used hafnium metallocene compounds as cathode interfacial layers for organic solar cells [OSCs]. A metallocene compound consists of a transition metal and two cyclopentadienyl ligands coordinated in a sandwich structure. For the fabrication of the OSCs, poly[3,4-ethylenedioxythiophene]:poly(styrene sulfonate), poly(3-hexylthiophene-2,5-diyl) + 66-phenyl C61 butyric acid methyl ester, bi...
Functionalized polyethylene-based nanocomposites were prepared by in situ polymerization of ethylene with modified or neat MCM-41 nanoparticles (NMCM-41). Two different synthetic approaches investigated to improve the compatibility between hydrophobic HDPE matrix and hydrophilic NMCM-41: (i) incorporation UA into polymeric copolymerization ethylene, promoted zirconocene catalyst under homogeneo...
Recently, we have identified the Al-alkenyl species iBuAl(oct-7-en-1-yl)2 (Al-1) as a promising long-chain branching (LCB) promoter in ethylene polymerization catalyzed by rac-{EBTHI}ZrCl2-based systems, proposing incorporation of its alkenyl moiety into growing polyethylene (PE) chain crucial step for LCB formation. The success process was attributed to high copolymerization ability selected c...
Titanocene and zirconocene ketene acetal derivatives have been prepared by reaction of the respective metallocene dichloride with the lithium enolate of isobutyric acid methyl ester. The crystal structure of (CsH s),Ti(CDOC(OCH 3):C(CH 3) is reported.
Metallocene complexes of the Group 3 metals and lanthanides have been utilized for cyclization/silylation reactions of polyunsaturated organic substrates. Acyclic dienes, trienes, enynes, and dienynes can be selectively cyclized to provide fiveand six-membered rings in high yields.
heterogeneous ziegler-natta and homogeneous metallocene catalysts exhibit greatly different active sitenature in olefin polymerization. in our previous study, it was reported that mgcl2-supported titanocenecatalysts can generate both ziegler-natta-type and metallocene-type active sites according to the type of activators.the dual active site nature of the supported titanocene catalysts was furt...
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