ja0c11259_si_001.pdf (17.92 MB)
Isotope Effect in the Activation of a Mechanophore
journal contribution
posted on 2020-12-31, 16:35 authored by Robert Nixon, Guillaume De BoIn mechanochemistry, molecules under
tension can react in unexpected
ways. The reactivity of mechanophores (mechanosensitive molecules)
can be controlled using various geometric or electronic factors. Often
these factors affect the rate of mechanical activation but sometimes
give rise to alternative reaction pathways. Here we show that a simple
isotope substitution (H to D) leads to a reversal of selectivity in
the activation of a mechanophore. Remarkably this isotope effect is
not kinetic in nature but emerges from dynamic effects in which deuteration
reduces the ability of the reactant to follow a post-transition-state
concerted trajectory on the bifurcated force-modified potential energy
surface. These results give a new insight into the reactivity of molecules
under tension.