Polyether macrocycles, interlocking

The interlocking of secondary amines with polyether macrocycles enables amines to activate H2 in the presence of B(CgF5)3. DF calculations show that the amine-macrocycle complex both preorganizes a frustrated Lewis pair minimum for H2 activation and stabilizes the product through strong hydrogen bonds. ... 

This [2]catenane is composed of a jt-electron-deficient tetracationic cyclophane interlocked with a Jt-electron-rich macrocyclic polyether. In addition to a mechanical bond, [jt Jt] stacking interactions between the complementary aromatic units, [C-H---0] hydrogen bonds between the a-bipyridinium hydrogen atoms and the poly-ether oxygen atoms, and [C-H---Jt] interactions between the 1,4-dioxybenzene hydrogen atoms and the p-phenylene spacers in the tetracationic cyclophane hold the two macrocyclic components together and control their relative movements in solution. As a result of the asymmetry of the tetracationic cyclophane, two transla-... 

The use of interlocked polyether-diimine macrocycle ligand (Fig. 5) has interesting implications for the coordination of metal ions, especially those of iron [32]. 

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