How small can a catenane be, if we consider quantum tunnelling?

Abstract

We explored the kinetic stability of the smallest possible alkane-based catenanes and pseudo-rotaxanes, focusing on their heavy atom quantum tunnelling instability. We found that the “corset effect” exerted by a ten-membered ring renders other rings unstable even under deep cryogenic conditions, where it may be taken as stable if tunnelling is neglected.