ABSTRACT
Click reactions have been introduced as highly reliable chemical processes, in which even complex molecular building blocks can be connected irreversibly by covalent bonds. Although reversible processes like supramolecular aggregation controlled by specific interactions like hydrogen bonding or metal complexation are also highly reliable and omnipresent in nature, they are rarely considered as click reactions. Mechanical processes in daily life associated with a click procedure depending only on shape recognition and space-filling are snap fasteners, snap fit buckels and ball detents and they are almost unknown in the nanoworld. This account defines such processes on a molecular basis and highlights some recent examples of star-shaped, shape-persistent mesogens designed to control the nanostructure of columnar liquid crystals for future photovoltaic applications. The click procedure leading to these structures is compared to related systems like the CPI and the LC shuttlecock.
Graphical abstract
![](/cms/asset/e81ef36a-c9da-4852-9f80-20041c2ccf36/tlct_a_1618936_uf0001_oc.jpg)
Acknowledgments
We are grateful to the Deutsche Forschungsgemeinschaft (DFG) for their financial support within the projects LE1571/5-1 and LE1571/8-1.
Disclosure statement
No potential conflict of interest was reported by the authors.