Fast Molecular Compression by a Hyperthermal Collision Gives Bond-Selective Mechanochemistry

TL;DR

This study demonstrates that hyperthermal collisions can induce bond-selective mechanochemical reactions in molecules by rapidly compressing and bending specific bonds, enabling access to otherwise thermally inaccessible reaction pathways.

Contribution

It introduces a novel method of inducing bond-selective reactions through hyperthermal collisions, revealing a new mechanochemical pathway for molecular transformation.

Findings

Bond-selective reactions observed at low collision energies.

Collision-induced compression triggers specific bond reactions.

Reactions access pathways unavailable through thermal activation.

Abstract

Using electrospray ion beam deposition, we collide the complex molecule Reichardt's Dye (C41H30NO+) at low, hyperthermal translational energy (2-50 eV) with a Cu(100) surface and image the outcome at single-molecule level by scanning tunneling microscopy. We observe bond-selective reaction induced by the translational kinetic energy. The collision impulse compresses the molecule and bends specific bonds, prompting them to react selectively. This dynamics drives the system to seek thermally inaccessible reactive pathways, since the compression timescale (sub-ps) is much shorter than the thermalization timescale (ns), thereby yielding reaction products that are unobtainable thermally.