Stimuli-responsive
molecular junctions, where the conductance can be altered by an external
perturbation, are an important class of nanoelectronic devices. These have
recently attracted interest as large effects can be introduced through
exploitation of quantum phenomena. We show here that significant changes in conductance
can be attained as a molecule is repeatedly compressed and relaxed, resulting
in molecular folding along a flexible fragment and cycling between an <i>anti</i>
and a <i>syn </i>conformation. Power spectral density analysis and DFT
transport calculations show that through-space tunnelling between two phenyl
fragments is responsible for the conductance increase as the molecule is
mechanically folded to the <i>syn</i> conformation. This phenomenon represents
a novel class of mechanoresistive molecular devices, where the functional
moiety is embedded in the conductive backbone and exploits intramolecular
nonbonding interactions, in contrast to most studies where mechanoresistivity
arises from changes in the molecule-electrode interface.