Conformationally Rigid Diamide Complexes of Zirconium: Electron Deficient Analogues of Cp2Zr
Conformationally Rigid Diamide Complexes of Zirconium: Electron Deficient Analogues of Cp2Zr
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锆的构象刚性二酰胺配合物：Cp2Zr 的缺电子类似物
DOI：
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发表时间：
1996
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影响因子：
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通讯作者：
J. Vittal
中科院分区：
文献类型：
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作者：
F. Guérin;D. H. Mcconville;J. Vittal
合成了含吡啶-二胺配体[2,6-(RNCH2)2NC5H3]2- （R = 2,6-二异丙基苯基，2,6-二乙基苯基（BDEP）， 2,6-二甲基苯基）的锆配合物。以[2,6-(RHNCH2)2NC5H3]和Zr(NMe2)4为原料，高收率制备了[2,6-(RNCH2)2NC5H3]Zr(NMe2)2混合酰胺配合物。混合酰胺与过量的ClSiMe3反应生成二氯化物[2,6-(RNCH2)2NC5H3]ZrCl2，产量接近定量。以[2,6-(RNCH2)2NC5H3]ZrCl2和2当量的MeMgBr为原料制备了二甲基配合物。单晶x射线衍射研究表明，（BDEP）ZrMe2具有扭曲的三角双棱柱结构，酰胺占据轴向位置。片段（BDEP）Zr模型的边界轨道与Cp2Zr的边界轨道非常相似，这表明含有吡啶-二胺配体的配合物可能是Cp2Zr的来源。
Zirconium complexes bearing a pyridine−diamide ligand [2,6-(RNCH2)2NC5H3]2- (R = 2,6-diisopropylphenyl, 2,6-diethylphenyl (BDEP), 2,6-dimethylphenyl) have been synthesized. The mixed amide complexes [2,6-(RNCH2)2NC5H3]Zr(NMe2)2 are prepared in high yield from [2,6-(RHNCH2)2NC5H3] and Zr(NMe2)4. The mixed amides react with excess ClSiMe3 to afford the dichlorides [2,6-(RNCH2)2NC5H3]ZrCl2 in nearly quantitative yield. Dimethyl complexes are prepared from [2,6-(RNCH2)2NC5H3]ZrCl2 and 2 equiv of MeMgBr. A single-crystal X-ray diffraction study of (BDEP)ZrMe2 revealed a distorted trigonal bipyramid structure with the amides occupying the axial positions. The frontier orbitals of a model of the fragment (BDEP)Zr are very similar the those of Cp2Zr, suggesting that complexes bearing the pyridine−diamide ligand may behave as sources of Cp2Zr.