Synthesis and Structural Analysis of (Arylimido)vanadium(V) Complexes Containing Phenoxyimine Ligands: New, Efficient Catalyst Precursors for Ethylene Polymerization
Synthesis and Structural Analysis of (Arylimido)vanadium(V) Complexes Containing Phenoxyimine Ligands: New, Efficient Catalyst Precursors for Ethylene Polymerization
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DOI：
10.1021/om800177g
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发表时间：
2008-05
期刊：
影响因子：
2.8
通讯作者：
Yoshifumi Onishi;Shohei Katao;M. Fujiki;K. Nomura
中科院分区：
文献类型：
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作者：
Yoshifumi Onishi;Shohei Katao;M. Fujiki;K. Nomura
一系列含有苯氧亚胺配体 V(NAr)Cl2[O-2-R-6-{(2,6-iPr2C6H3)N=CH}C6H3] [Ar = 2,6-Me2C6H3; R = H (1a), Me (1b), tBu (1c)] 由 V(NAr)Cl3 与 LiO-2-R-6-[(2,6-iPr2C6H3)N=CH]C6H3 制备，产率 64−78%。 X射线晶体学测定的1a−c结构表明，这些配合物在钒周围具有扭曲的方锥体结构，由扭曲方锥体顶端的芳基酰亚胺配体和N,O-螯合配体组成，形成一个包含芳氧环和亚氨基氮的平面。 1c的Cl−V−Cl键角[90.49(2)°]明显小于1a、b中的键角[分别为91.97(7)°、91.25(2)°]，并且1c中的V−N(亚胺)键距[2.203(2)A]比1b、c中的短[2.216(4)、2.2165(17)分别是A]。这些配合物（尤其是 1c）在 MAO 和芳氧基中的邻位取代基存在下对乙烯聚合表现出显着的催化活性。
A series of (arylimido)vanadium(V) complexes containing phenoxyimine ligands of the type V(NAr)Cl2[O-2-R-6-{(2,6-iPr2C6H3)N═CH}C6H3] [Ar = 2,6-Me2C6H3; R = H (1a), Me (1b), tBu (1c)] have been prepared in 64−78% yields from V(NAr)Cl3 with LiO-2-R-6-[(2,6-iPr2C6H3)N═CH]C6H3. The structures for 1a−c determined by X-ray crystallography indicate that these complexes have distorted square-pyramidal structures around vanadium, consisting of the arylimido ligands in the apical site of a distorted square-pyramid and the N,O-chelate ligand, which forms a plane including both the aryloxo ring and the imino nitrogen. The Cl−V−Cl bond angle for 1c [90.49(2)°] is apparently smaller than those in 1a,b [91.97(7)°, 91.25(2)°, respectively], and the V−N(imine) bond distance in 1c [2.203(2) A] is shorter than those in 1b,c [2.216(4), 2.2165(17) A, respectively]. These complexes (especially 1c) exhibited notable catalytic activities for ethylene polymerization in the presence of MAO, and the ortho substituent in the aryloxo...