Synthesis of (1-adamantylimido)vanadium(V) complexes containing aryloxo, ketimide ligands: effect of ligand substituents in olefin insertion/metathesis polymerization.
Synthesis of (1-adamantylimido)vanadium(V) complexes containing aryloxo, ketimide ligands: effect of ligand substituents in olefin insertion/metathesis polymerization.
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DOI：
10.1021/ic800347n
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发表时间：
2008-06
影响因子：
4.6
通讯作者：
Wenjuan Zhang;K. Nomura
中科院分区：
文献类型：
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作者：
Wenjuan Zhang;K. Nomura
一系列含有V（NAd）Cl 2（L）[Ad = 1-金刚烷基; L = O-2，6-Me_2C_6H_3（2），O-2，6-（i）Pr_2C_6H_3（3），NC（t）Bu_2（5），NC（t）Bu）CH_2SiMe_3（6），NC（t）Bu）Ph（7），NCPh_2（8）]，其又由VOCl 3通过在辛烷中用1-金刚烷基异氰酸酯处理、通过在Et 2 O中用相应的锂盐（苯酚锂、酮亚胺锂）处理而制备。这些配合物（2，3，5-8）通过核磁共振谱和元素分析进行了鉴定，并通过X射线晶体学确定了2和5的结构。V（NAd）Cl_3与2，6-二甲基苯酚在正己烷中反应，得到三芳氧基类似物V（NAd）（O-2，6-Me_2C_6H_3）_3（4），其结构经X射线单晶衍射测定。8在甲苯中逐渐分解，得到二聚体物质[N（Ad）H3]（+）[V2（μ 2-Cl）3Cl 2（NAd）2（NCPh 2）2]（-）（10），但8稳定为PMe 3配位物质V（NAd）Cl 2（NCPh 2）（PMe 3）2（9）：9和10的结构通过X射线晶体学测定。这些配合物作为催化剂前体的乙烯聚合在MAO的存在下进行了评价。酮酰亚胺类似物，特别是5，表现出中等的催化活性，并且在一系列V（NAd）Cl 2（L）-MAO催化剂体系中的活性按以下顺序增加：L = NC（t）Bu 2（5，516 kg-PE/mol x V x h）> NC（（t）Bu）Ph（7，300）> NCPh 2（8，105）> NC（（t）Bu）CH 2 SiMe 3（6，70. 8）。发现这些配合物（2，3，5，6）作为催化剂前体对于在MeMgBr和PMe 3存在下的顺丁烯（NBE）的开环易位聚合（ROMP）是有效的。
A series of (1-adamantylimido)vanadium(V) complexes containing anionic donor ligands of the type, V(NAd)Cl2(L) [Ad = 1-adamantyl; L = O-2,6-Me2C6H3 (2), O-2,6-(i)Pr2C6H3 (3), NC(t)Bu2 (5), NC((t)Bu)CH2SiMe3 (6), NC((t)Bu)Ph (7), NCPh2 (8)], have been prepared from V(NAd)Cl 3, which was in turn prepared from VOCl3 by treatment with 1-adamantylisocyanate in octane, by treatment with the corresponding lithium salts (lithium phenoxides, lithium ketimides) in Et2O. These complexes (2, 3, 5-8) were identified by NMR spectroscopy and elemental analysis, and the structures for 2 and 5 were determined by X-ray crystallography. The reaction of V(NAd)Cl3 with 2,6-dimethylphenol in n-hexane afforded the tris(aryloxo) analogue V(NAd)(O-2,6-Me2C6H3)3 (4), the structure of which was determined by X-ray crystallography. 8 gradually decomposed in toluene to give a dimeric species, [N(Ad)H3](+)[V2(mu2-Cl)3Cl2(NAd)2(NCPh2)2](-) (10), but 8 was stabilized as a PMe 3 coordinated species, V(NAd)Cl2(NCPh2)(PMe3)2 (9): the structures for 9 and 10 were determined by X-ray crystallography. These complexes were evaluated as catalyst precursors for ethylene polymerization in the presence of MAO. The ketimide analogues, especially 5, exhibited moderate catalytic activity, and the activity with a series of V(NAd)Cl2(L)-MAO catalyst systems increased in the order: L = NC(t)Bu2 (5, 516 kg-PE/mol x V x h) > NC((t)Bu)Ph (7, 300) > NCPh2 (8, 105) > NC((t)Bu)CH2SiMe3 (6, 70.8). These complexes (2, 3, 5, 6) were found to be effective as catalyst precursors for the ring-opening metathesis polymerization (ROMP) of norbornene (NBE) in the presence of MeMgBr and PMe3.