Topological isomers catenanes

The evolving domain of radial, as well as linear, addition of modules to form an expanding moiety, in a manner akin to the development of polymers, referred to as "dendrimers", is examined and nomenclated The direct inclusion of topology in the description of isomers, once a very insignificant part of chemical nomenclature, is now a factor to be reckoned with, not only for the small class traditionally referred to as "topological" (including catenanes, rotaxanes, and knots), but also as new compositions of matter, such as the endothelial fullerenes, are formulated. 

Also known are other types of topological isomers which draw the researchers attention, but they exist only on paper so far. Catenanes and rotaxanes are the only topological structure classes which have been investigated experimentally. 

Figure 4-23. Topological isomers of the [3]-catenane (L1079)(L1163)2, in which the isomers have the keto-groups at AB or at AB. ...

Confounds which contain topolopcal bonds are called topological They represent topological isomers of two sq)arate molecules of the components (two rings for a catenane a ring and a linear molecule with large bulky stibstituents, dumb-bells , for a rotaxane... 

II) Polydisperse isomers are characterized by identical MWDs. Example are monocyclic polymers and catenanes prepared from the same linear precursor polymers. In this case, the term polydisperse topological isomers are a long but correct lable. 

---