Self-Assembled Catenanes, Knots, and Links and Synergistic Effects of Weak Interactions

Molecular topology was introduced in 1961 by Edel Wasserman and Harry Frisch1 following the work of Wasserman. Nonmechanically interlocked rings were obtained from macrocyclic hydrocarbons called catenanes2 (from the Latin catena which 17.1Introduction. ………………………………………………………………………………………. 321 17.1.1 Molecular Topology and Need for Multiple Weak Interactions in Synergy. ……………………………………………………………………………. 321 17.1.2 Self-Assembly of Topological Structures. …………………………………. 323 17.2 Interactions Governing Assemblies of Knots and Links. ……………………….. 323 17.2.1 Metal Coordination. ………………………………………………………………… 323 17.2.2 Anion Coordination. ………………………………………………………………. 325 17.2.3 Hydrogen Bonding Interactions. ………………………………………………. 325 17.2.4 π-Stacking Interactions. ………………………………………………………….. 326 17.3 Template-Directed Self-Assembly toward Complex Molecular Knots and Links. ……………………………………………………………………………… 327 17.3.1 Trefoil knot (TK). ………………………………………………………………….. 327 17.3.2 Solomon Link. ………………………………………………………………………. 328 17.3.3 Pentafoil Knot. ………………………………………………………………………. 329 17.3.4 Borromean Ring. …………………………………………………………………… 329 17.4 Conclusion and Perspectives. ……………………………………………………………… 331 References. ………………………………………………………………………………………………. 331 means chain). Their concept of topological isomers was summarized in a recent comprehensive review on the subject3 as “two objects containing the same atoms and chemical bond connectivities, but that cannot be interconverted by any deformation action in three-dimensional space.” Figure 17.1 represents some of the most common examples of knots and links such as the [2]catenate, trefoil knot, Solomon link, pentafoil knot, and Borromean ring.