Catenanes design

Megiatto JD, Schuster DI, Abwandner S et al (2010) [2]Catenanes decorated with porphyrin and [60]fullerene groups design, convergent synthesis, and photoinduced processes. J Am Chem Soc 132 3847-3861... 

The pioneering papers by Stoddart and Sauvage have stimulated the design of a variety of movable rotaxanes and catenanes, whose controlled motion is promoted by a redox change. In all cases, the process of the redox-driven intramolecular motion can be described by a square scheme, as illustrated in Fig. 2.1. 

In this and the following sections self-assembling catenanes incorporating (en)Pd(II) units in their backbones are emphasized [21]. Discussion will be focused on the rational design, self-assembly, mechanistic aspect, and chemical manipulation of the transition metal-linked catenanes. 

Successful self-assembly of catenanes 23 and 25 and their remarkable stability imply that rectangular box structures for the component rings are very effective for catenation. Thus, we also designed the construction of rectangular frameworks from a set of 11 and two different ligands. Surprisingly, these three-component systems worked very well and we observed highly efficient three-component-... 

Another question on the self-assembly of metal-linked catenanes is whether it is possible to design various catenane molecules rationally on the basis of the same principle. To elucidate the major factors that control the self-assembly of inter-... 

The great variety of incorporable building blocks also offers the synthetic chemist many potential structural and functional design possibilities. The insertion of, e.g., photo-responsive elements, groups with further supramolecular derivatization potential, or sulfonamide units which enable subsequent inter- and intramolecular linkage of catenanes and rotaxanes might render good service in the development of molecular switches [64] and devices [65]. 

We have recently reported that compound 7a shows a smectic-smectic phase transition associated with the change of the photoluminescent color (Fig. 7) [33]. Compound 7a has a 2,6-diethynylanthracene group as a photoluminescent core. This molecule has fork-like mesogens which consist of tetra(ethylene oxide) and p-(4-/ra .v-pentylcyclohexyl)phenyl moieties. A similar molecular design was previously applied to induce smectic liquid crystallinity for rotaxanes and catenanes [39—41 ]. 

A review on molecular machines useful for the design of chemosensors emphasizing, among others, modified CDs as molecular sensors, and on rotaxanes and catenanes is published [36],... 

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