# Interlocked cyclic compounds

Being new to chemistry, there may ought to be some properties I couldn't understand fully. One of them being cyclic compounds.

One particular question about this is, whether these cyclic compounds, say benzene rings 'link' in-between one another like a chain. Having one molecule chain of one benzene molecule, go through the center of another, before closing back up as a ring.

Unfortunately, I couldn't seem to find any term describing it for further research.

This may be a stupid question or have been asked before, but since I couldn't find my answer anywhere, hopefully someone may either point out why wouldn't this exist in any case or redirect me to an answer.

The carbon-carbon bond length in benzene is 139 pm. Therefore, the approximate side to side distance in benzene is $\mathrm{2 \cdot 139~ pm \cdot cos(30°)= 241~pm}$. The van der Waals radius is defined as "half of the internuclear separation of two non-bonded atoms of the same element on their closest possible approach" (source). The van der Waals radius for carbon is 170 pm, meaning that the closest approach for two non-bonded carbon atoms is around 340 pm. This value is significantly larger than the 241 pm side-to-side distance we calculated above for benzene. This means that a carbon atom cannot pass through the interior of a benzene ring, at least not for carbon atoms with energies typically found in an organic laboratory.