The synthesis of organolanthanide compounds identified as LnCp^＊（MS）2PzA, Ln = Sm, Tb, Yb （MS = methanesulfonate, Cp^＊ = pentamethylcyclopentadienyl, and PzA = pyrazinamide）, by the reaction of coordination comp...The synthesis of organolanthanide compounds identified as LnCp^＊（MS）2PzA, Ln = Sm, Tb, Yb （MS = methanesulfonate, Cp^＊ = pentamethylcyclopentadienyl, and PzA = pyrazinamide）, by the reaction of coordination compounds Ln（MS）3（PzA）4 with NaCp in THF was reported. The complexes were formulated according to elemental analyses, complexometric titration with EDTA （%Ln）, and ^1H NMR. IR spectroscopy revealed that PzA coordinates with lanthanide （Ⅲ） ions and methanesulfonate coordinates via oxygen atoms in a non-equivalent manner. In preliminary catalytic studies, these compounds were active in styrene polymerization that used MAO as a cocatalyst with an activity of 12.3 kg PS molSm^-1h^-1. Differential scanning calorimetry （DSC） of polystyrene showed that the polymer was mainly atactic.展开更多
The neodymium complex supported on styrene-maleic anhydride copolymer (SMA·Nd) has been prepared for the first time and found to be a highly effective catalyst for the polymerization of styrene. The SMA·Nd p...The neodymium complex supported on styrene-maleic anhydride copolymer (SMA·Nd) has been prepared for the first time and found to be a highly effective catalyst for the polymerization of styrene. The SMA·Nd polymeric complex is characterized by IR and its catalytic activity, and the polymerization features have been investigated in comparison with that of the conventional Ziegler-Natta catalysts. When [Nd]=1×10^(-3) mol/L, [M]=5mol/L, Al/Nd=170(mol ratio) and CCl_4/Nd=50(mol ratio), the polymerization conversion of styrene gets to 51.6% in six hours, and the catalytic activity reaches 1852 gPS/gNd, which is much higher than that of conventional rare earth catalysts. The polymerization reaction has an induction period and shows some characteristics of chain polymerization. The polymerization rate is the first order with respect to the concentration of styrene monomer. Addition of FeCl_3 does not suppress the polymerization.展开更多
基金Project supported by the Fundacā de Amparo à Pesquisa do Estado de Sāo Paulo and CNPq Conselho Nacional de Desenvolvimento Científico e Teenológico
文摘The synthesis of organolanthanide compounds identified as LnCp^＊（MS）2PzA, Ln = Sm, Tb, Yb （MS = methanesulfonate, Cp^＊ = pentamethylcyclopentadienyl, and PzA = pyrazinamide）, by the reaction of coordination compounds Ln（MS）3（PzA）4 with NaCp in THF was reported. The complexes were formulated according to elemental analyses, complexometric titration with EDTA （%Ln）, and ^1H NMR. IR spectroscopy revealed that PzA coordinates with lanthanide （Ⅲ） ions and methanesulfonate coordinates via oxygen atoms in a non-equivalent manner. In preliminary catalytic studies, these compounds were active in styrene polymerization that used MAO as a cocatalyst with an activity of 12.3 kg PS molSm^-1h^-1. Differential scanning calorimetry （DSC） of polystyrene showed that the polymer was mainly atactic.
文摘The neodymium complex supported on styrene-maleic anhydride copolymer (SMA·Nd) has been prepared for the first time and found to be a highly effective catalyst for the polymerization of styrene. The SMA·Nd polymeric complex is characterized by IR and its catalytic activity, and the polymerization features have been investigated in comparison with that of the conventional Ziegler-Natta catalysts. When [Nd]=1×10^(-3) mol/L, [M]=5mol/L, Al/Nd=170(mol ratio) and CCl_4/Nd=50(mol ratio), the polymerization conversion of styrene gets to 51.6% in six hours, and the catalytic activity reaches 1852 gPS/gNd, which is much higher than that of conventional rare earth catalysts. The polymerization reaction has an induction period and shows some characteristics of chain polymerization. The polymerization rate is the first order with respect to the concentration of styrene monomer. Addition of FeCl_3 does not suppress the polymerization.
