Ethylenebis(salicylideneiminato)zirconium dichloride : Crystal structure and use as a heterogeneous catalyst in the polymerization of ethylene
Ethylenebis(salicylideneiminato)zirconium dichloride : Crystal structure and use as a heterogeneous catalyst in the polymerization of ethylene
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DOI：
10.1021/ma960512r
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发表时间：
1997-01
期刊：
影响因子：
5.5
通讯作者：
T. Repo;M. Klinga;P. Pietikäinen;M. Leskelä;A. Uusitalo;T. Pakkanen;K. Hakala;P. Aaltonen;B. Löfgren
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文献类型：
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作者：
T. Repo;M. Klinga;P. Pietikäinen;M. Leskelä;A. Uusitalo;T. Pakkanen;K. Hakala;P. Aaltonen;B. Löfgren
在Schiff碱salen [salen = N，N '-亚乙基双（水杨醛亚胺基）]二氯化锆配合物Zr（salen）Cl 2（THF）的固态结构中，四齿配体C20 H22 Cl 2N 2 O3 Zr占据四个假五角双锥配位。配位球由一个THF分子完成，两个氯离子被迫进入反式位置。除去THF，而Zr（salen）Cl 2（THF）在甲苯中加热，导致六配位的配合物与两个氯配体假定顺式位置。该性质被成功地用于制备均相Zr（salen）Cl 2催化剂前体。在SiO2存在下，在甲苯中加热Zr（salen）Cl 2（THF）导致Zr（salen）Cl 2沉积在二氧化硅载体上，产生非均相催化剂，其在助催化剂甲基铝氧烷存在下在80 °C和低乙烯压力下在乙烯聚合中显示出可接受的活性。
In the solid-state structure of the Schiff base salen [salen = N,N‘-ethylenebis(salicylideneiminato)] zirconium dichloride complex Zr(salen)Cl2(THF), C20H22Cl2N2O3Zr, a quadridentate ligand, occupies four sites in the pseudopentagonal bipyramidal coordination. The coordination sphere is completed by one THF molecule, and two chloride ions are forced into the trans-position. Removal of THF, while Zr(salen)Cl2(THF) is heated in toluene, leads to a six-coordinated complex with the two chloride ligands assuming the cis-position. This property was successfully utilized in the preparation of a homogeneous Zr(salen)Cl2 catalyst precursor. Heating of Zr(salen)Cl2(THF) in toluene in the presence of SiO2 causes deposition of Zr(salen)Cl2 on to the silica support, producing a heterogeneous catalyst, which shows an acceptable activity in ethylene polymerization at 80 °C and at low ethylene pressures in the presence of the cocatalyst methylaluminoxane.