Precision molecular threading/dethreading

Abstract: The general principles guiding the design of molecular
machines based on interlocked structures are well known.
Nonetheless, the identification of suitable molecular components for
a precise tuning of the energetic parameters that determine the
mechanical link is still challenging. Indeed, what are the reasons of
the “all-or-nothing” effect, which turns a molecular “speed-bump” into
a stopper in pseudorotaxane-based architectures? Here we
investigate the threading and dethreading processes for a
representative class of molecular components, based on symmetric
dibenzylammonium axles and dibenzo[24]crown-8 ether, with a joint
experimental-computational strategy. From the analysis of
quantitative data and an atomistic insight, we derive simple rules
correlating the kinetic behaviour with the substitution pattern, and
provide rational guidelines for the design of modules to be integrated
in molecular switches and motors with sophisticated dynamic
features