4667-38-3Relevant articles and documents
Ethylene polymerization reactions with multicenter Ziegler-Natta catalysts-manipulation of active center distribution
Kissin, Yury V.,Mink, Robert I.
, p. 4219 - 4229 (2010)
This article describes ethylene/1-hexene copolymerization reactions with a supported titanium-based, multicenter Ziegler-Natta catalyst. The catalyst was modified by pretreating its solid precursor with AlEt2Cl and with similar organoaluminum chlorides, Al2Et3Cl3, AlEtCl2, and AlMe2Cl. Testing of the untreated and the pretreated catalysts in copolymerization reactions under standard reaction conditions demonstrated that the modifying agents produce two changes in the catalyst. First, the pretreatment significantly reduces the reactivity of active centers that produce high molecular weight, highly crystalline copolymer components with a low 1-hexene content. Second, the pretreatment noticeably increases the reactivity of active centers that produce low molecular weight copolymer components with a high 1-hexene content. The first effect is caused by Lewis acidbase interactions of the modifiers with the active centers, whereas the second (activating) effect is due to the removal of catalyst poisons (organosilicon compounds generated in the process of the catalyst synthesis) by AlEt2Cl.
Synthesis, structure, immobilization and solid-state NMR of new dppp- and tripod-type chelate linkers
Bogza, Mona,Oeser, Thomas,Blümel, Janet
, p. 3383 - 3389 (2007/10/03)
Chelating phosphines incorporating ethoxysilane functions for immobilizations have been synthesized and fully characterized. (EtO)Si(CH 2PPh2)3, (EtO)2Si(CH 2PPh2)2, and Si(CH2PPh 2)4 could be prepared in high yields from cheap starting materials. The ethoxysilanes, as well as a Pd complex thereof have been characterized by X-ray structures, and immobilized on silica. The success of the immobilization was proved by 31P solid-state NMR of the dry materials and of the suspensions. Two representative chelate metal complexes, (EtO)2Si(CH2PPh2)2PdCl2 and (EtO)Si(CH2PPh2)3W(CO)3 have been synthesized, characterized and immobilized.
Recovery of trimethylchlorosilane from its azeotropic mixture with SiCl4
Voronkov,Baryshok,Kuznetsova
, p. 2091 - 2094 (2007/10/03)
Reaction of tetraethoxysilane with the azeotropic mixture Me3SiCl-SiCl4 in the presence of certain cyclic (tetrahydrofuran, dioxane) and acyclic (diethyl ether) ethers, ethanol, or dimethylformamide was studied with the aim of SiMe3Cl recovery.