The Experts below are selected from a list of 15624 Experts worldwide ranked by ideXlab platform
Gerard Parkin - One of the best experts on this subject based on the ideXlab platform.
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synthesis and structural characterization of tris 2 pyridonyl methyl complexes of zinc and thallium a new class of metallacarbatranes and a monovalent thallium Alkyl Compound
Dalton Transactions, 2013Co-Authors: Ahmed Alharbi, Yi Rong, Gerard ParkinAbstract:Tris(2-pyridonyl)methanes may be synthesized via the reactions of the respective 2-pyridone with CHX3 (X = Cl, Br) and K2CO3 in the presence of [Bu(n)4N]Br, followed by acid-catalyzed isomerization with camphorsulfonic acid. These Compounds provide access to a new class of Alkyl ligands that feature oxygen donors and are capable of forming metallacarbatranes and a monovalent thallium Alkyl Compound.
Ahmed Alharbi - One of the best experts on this subject based on the ideXlab platform.
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synthesis and structural characterization of tris 2 pyridonyl methyl complexes of zinc and thallium a new class of metallacarbatranes and a monovalent thallium Alkyl Compound
Dalton Transactions, 2013Co-Authors: Ahmed Alharbi, Yi Rong, Gerard ParkinAbstract:Tris(2-pyridonyl)methanes may be synthesized via the reactions of the respective 2-pyridone with CHX3 (X = Cl, Br) and K2CO3 in the presence of [Bu(n)4N]Br, followed by acid-catalyzed isomerization with camphorsulfonic acid. These Compounds provide access to a new class of Alkyl ligands that feature oxygen donors and are capable of forming metallacarbatranes and a monovalent thallium Alkyl Compound.
Gerhard Luft - One of the best experts on this subject based on the ideXlab platform.
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influence of aluminium Alkyl Compounds on the high pressure polymerization of ethylene with ternary metallocene based catalysts investigation of chain transfer to the aluminium
Macromolecular Materials and Engineering, 2002Co-Authors: Christian Gotz, Alexander Rau, Gerhard LuftAbstract:The influence of aluminium Alkyl Compounds on metallocene-catalyzed high pressure polymerizations of ethylene has been investigated at 150 MPa and 180°C in a continuously operated autoclave. The catalysts were based on the metallocenes bis(cyclopentadienyl)zirconium dichloride (Cp2ZrCl2) and diphenylmethylene (cyclopentadienylfluorenyl)zirconium dichloride (Ph2C-(CpFlu)ZrCl2), which were preactivated outside the reactor with triisobutylaluminium (TiBA) and N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate (DMAP, [PhNHMe2][B(C6F5)4]). The concentrations of triisobutylaluminium (TiBA) and triethylaluminium (TEA) in the reactor were varied over a wide range, using a separate dosing for these two aluminium Alkyl Compounds. Productivity and polymer properties strongly depended on the type and the concentration of the aluminium Alkyl Compound used. Highest productivities and molecular weights were obtained with low concentrations of TiBA in the reactor. Up to a concentration of 30 molppm Al in the reactor, unimodal polymers were formed with Mw/Mn between 2 and 3. With higher aluminium concentrations the products formed contained small amounts of waxes, due to oligomerization catalyzed by the aluminium Alkyl Compounds. The molecular weight distributions (MWDs) of these products could be described as a superimposition of two Schulz-Zimm distributions. All MWDs were analyzed with regard to the amount of waxes produced by ethylene oligomerization and with regard to the influence of chain transfer reactions to the aluminium. The rate constants of chain transfer to aluminium, in relation to the rate constants of insertion of ethylene, were estimated.
Yi Rong - One of the best experts on this subject based on the ideXlab platform.
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synthesis and structural characterization of tris 2 pyridonyl methyl complexes of zinc and thallium a new class of metallacarbatranes and a monovalent thallium Alkyl Compound
Dalton Transactions, 2013Co-Authors: Ahmed Alharbi, Yi Rong, Gerard ParkinAbstract:Tris(2-pyridonyl)methanes may be synthesized via the reactions of the respective 2-pyridone with CHX3 (X = Cl, Br) and K2CO3 in the presence of [Bu(n)4N]Br, followed by acid-catalyzed isomerization with camphorsulfonic acid. These Compounds provide access to a new class of Alkyl ligands that feature oxygen donors and are capable of forming metallacarbatranes and a monovalent thallium Alkyl Compound.
Christian Gotz - One of the best experts on this subject based on the ideXlab platform.
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influence of aluminium Alkyl Compounds on the high pressure polymerization of ethylene with ternary metallocene based catalysts investigation of chain transfer to the aluminium
Macromolecular Materials and Engineering, 2002Co-Authors: Christian Gotz, Alexander Rau, Gerhard LuftAbstract:The influence of aluminium Alkyl Compounds on metallocene-catalyzed high pressure polymerizations of ethylene has been investigated at 150 MPa and 180°C in a continuously operated autoclave. The catalysts were based on the metallocenes bis(cyclopentadienyl)zirconium dichloride (Cp2ZrCl2) and diphenylmethylene (cyclopentadienylfluorenyl)zirconium dichloride (Ph2C-(CpFlu)ZrCl2), which were preactivated outside the reactor with triisobutylaluminium (TiBA) and N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate (DMAP, [PhNHMe2][B(C6F5)4]). The concentrations of triisobutylaluminium (TiBA) and triethylaluminium (TEA) in the reactor were varied over a wide range, using a separate dosing for these two aluminium Alkyl Compounds. Productivity and polymer properties strongly depended on the type and the concentration of the aluminium Alkyl Compound used. Highest productivities and molecular weights were obtained with low concentrations of TiBA in the reactor. Up to a concentration of 30 molppm Al in the reactor, unimodal polymers were formed with Mw/Mn between 2 and 3. With higher aluminium concentrations the products formed contained small amounts of waxes, due to oligomerization catalyzed by the aluminium Alkyl Compounds. The molecular weight distributions (MWDs) of these products could be described as a superimposition of two Schulz-Zimm distributions. All MWDs were analyzed with regard to the amount of waxes produced by ethylene oligomerization and with regard to the influence of chain transfer reactions to the aluminium. The rate constants of chain transfer to aluminium, in relation to the rate constants of insertion of ethylene, were estimated.