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On the molecular level, the interlocked molecules cannot be separated without the breaking of the covalent bonds that comprise the conjoined molecules; this is referred to as a mechanical bond. Examples of mechanically interlocked molecular architectures include catenanes, rotaxanes, molecular knots, and molecular Borromean rings.
The interlocked rings rotate with respect to one another. This motion can often be evaluated by NMR spectroscopy, among other methods.When molecular recognition motifs exist in the finished catenane (usually those that were used to synthesize the catenane), the catenane can have one or more thermodynamically preferred positions of the rings with respect to each other (recognition sites).
In chemistry, molecular Borromean rings are an example of a mechanically-interlocked molecular architecture in which three macrocycles are interlocked in such a way that breaking any macrocycle allows the others to dissociate. They are the smallest examples of Borromean rings.
In order to access the molecular Borromean ring consisting of three unequal cycles a step-by-step synthesis was proposed by Jay S. Siegel and coworkers. [47] In physics, a quantum-mechanical analog of Borromean rings is called a halo state or an Efimov state, and consists of three bound particles that are not pairwise bound.
Rotaxane synthesis can be carried out via a "capping," "clipping, "slipping" or "active template" mechanism. Synthesis via the capping method relies strongly upon a thermodynamically driven template effect; that is, the "thread" is held within the "macrocycle" by non-covalent interactions, for example rotaxinations with cyclodextrin macrocycles involve exploitation of the hydrophobic effect.
A class of mechanically interlocked molecules derived from catenanes where a large macrocycle backbone connects at least three small rings in the shape of a necklace (see image for example). A molecular necklace consisting of a large macrocycle threaded by n-1 rings (hence comprising n rings) is represented as [n]MN. [60]
A molecular topology is an area in chemistry that involves different mechanically-interlocked molecular architectures. Pages in category "Molecular topology" The following 14 pages are in this category, out of 14 total.
An interwoven grid complex has been used to template the synthesis of a doubly-twisted [2]catenane (otherwise known as a Solomon Link). [5] The unique arrangement of interwoven ligands around the planar array of iron, zinc, or cobalt ions generated the crossing points required to covalently trap the interlocked structure using ring-closing metathesis.