# Ion-Induced Molecular Growth in Clusters of Small Hydrocarbon Chains

## TL;DR

This study investigates how collisions between 3 keV Ar$^+$ ions and small hydrocarbon clusters induce molecular growth, potentially forming aromatic rings, relevant to interstellar and atmospheric chemistry.

## Contribution

It reveals ion-induced molecular growth mechanisms in hydrocarbon clusters, highlighting processes driven by knockout collisions that can lead to aromatic ring formation.

## Key findings

- Molecular growth occurs within hydrocarbon clusters during ion collisions.
- Knockout processes are identified as the driving mechanism.
- Potential relevance to interstellar and atmospheric chemistry.

## Abstract

We report on studies of collisions between 3 keV Ar$^+$ projectile ions and neutral targets of isolated 1,3-butadiene (C$_4$H$_6$) molecules and cold, loosely bound clusters of these molecules. We identify molecular growth processes within the molecular clusters that appears to be driven by knockout processes and that could result in the formation of (aromatic) ring structures. These types of reactions are not unique to specific projectile ions and target molecules, but will occur whenever atoms or ions with suitable masses and kinetic energies collide with aggregates of matter, such as carbonaceous grains in the interstellar medium or aerosol nanoparticles in the atmosphere.