Zhang Ying-Ying, Zhang Long, Lin Yue-Jian, Jin Guo-Xin
Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Collaborative Innovation Center of Chemistry for Energy Materials the Department of Chemistry, Fudan University, Shanghai 200433 (P. R. China).
Chemistry. 2015 Oct 12;21(42):14893-900. doi: 10.1002/chem.201502194. Epub 2015 Aug 28.
The design and synthesis of mixed-metal coordination cages, which can act as hosts to encapsule guest molecules, is a subject of intensive research, and the utilization of metalloligand is an effective method to construct a designed heterometallic architecture. Herein, a series of heterometallic cages with half-sandwich Rh, Ir and Ru fragments using Cu(II) -metalloligand as a building block by a stepwise approach is reported. The cavity sizes of the cages could be controlled easily by the lengths of the organic ligands. Because the metalloligands in the oxalate-based cage are somewhat distorted and concave, there are weak Cu⋅⋅⋅O interactions in the molecules, forming a binuclear copper unit. By increasing the height of the cages using longer ligands, 2,5-dichloro-3,6-dihydroxy-1,4-benzoquinone (H2 CA), the organometallic boxes display interesting host-guest behavior, which are made large enough to accommodate some large molecules, such as pyrene and [Pt(acac)2 ]. Interestingly, the heterometallic cage with larger cavity size can transfer into a homometallic hexanuclear prism in the presence of pyrazine.
混合金属配位笼的设计与合成是一个深入研究的课题，这种配位笼可作为主体来包封客体分子，而金属配体的利用是构建特定异金属结构的有效方法。在此，报道了一系列以Cu(II) -金属配体为结构单元，通过逐步方法合成的带有半夹心Rh、Ir和Ru片段的异金属笼。笼的空腔尺寸可通过有机配体的长度轻松控制。由于基于草酸盐的笼中的金属配体有些扭曲且呈凹形，分子中存在弱的Cu⋅⋅⋅O相互作用，形成双核铜单元。通过使用更长的配体2,5 -二氯-3,6 -二羟基-1,4 -苯醌（H2 CA）增加笼的高度，有机金属盒表现出有趣的主客体行为，其空腔大到足以容纳一些大分子，如芘和[Pt(acac)2 ]。有趣的是，具有较大空腔尺寸的异金属笼在吡嗪存在下可转变为同金属六核棱柱。
