Site-Selective Ligand Exchange on a Heteroleptic TiIV Complex Towards Stepwise Multicomponent Self-Assembly
Site-Selective Ligand Exchange on a Heteroleptic TiIV Complex Towards Stepwise Multicomponent Self-Assembly
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DOI：
10.1002/chem.200903509
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发表时间：
2010-01-01
影响因子：
4.3
通讯作者：
Shionoya, Mitsuhiko
中科院分区：
文献类型：
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作者：
Sakata, Yoko;Hiraoka, Shuichi;Shionoya, Mitsuhiko
在弱碱存在下，除了已报道的[Ti1(2)(Acac)](-)(acac=乙酰丙酮)配合物外，还选择性地合成了一系列具有异构性的[Ti1(2)X](-)配合物。比较研究表明，[Ti1(2)(Trop)](-)(trop=tropolate)比[Ti1(2)(Acac)](-)络合物更稳定，允许在[Ti1(2)(Acac)](-)上用trop取代acac。在保留Pd-II中心配位结构的情况下，异核Pd-II-Ti-IV环上也发生了以Ti-IV为中心的选择性配位交换反应。两个Ti-IV中心之间的分子内和分子间通过柔性或刚性的双托洛酮桥联配体分别提供了四核和八核Pd-II-Ti-IV络合物。只有通过一步一步的合成路线，才能有效地构建这些高阶结构。
A series of heteroleptic [Ti1(2)X](-) complexes have been selectively constructed from a mixture of Ti-IV ions, a pyridyl catechol ligand (H(2)1; H(2)1 = 4-(3-pyridyl)catechol), and various bidentate ligands (HX) in the presence of a weak base, in addition to a previously reported [Ti1(2)(acac)](-) (acac = acetylacetonate) complex. Comparative studies of these Ti-IV complexes revealed that [Ti1(2)(trop)](-) (trop = tropolonate) is much more stable than the [Ti1(2)(acac)](-) complex, which allows the replacement of acac with trop on the [Ti1(2)(acac)](-) complex. This Ti-IV-centered site-selective ligand exchange reaction also takes place on a heteronuclear Pd-II-Ti-IV ring complex with the preservation of the Pd-II-centered coordination structures. Intra- and intermolecular linking between two Ti-IV centers with a flexible or a rigid bis-tropolone bridging ligand provided a tetranuclear and an octanuclear Pd-II-Ti-IV complex, respectively. These higher-order structures could be efficiently constructed only through a step-wise synthetic route.