Imaging of Alignment, Deformation and Dissociation of CS2 Molecules using Ultrafast Electron Diffraction

TL;DR

This study employs ultrafast electron diffraction and femtosecond laser mass spectrometry to image and analyze the structural dynamics of CS2 molecules in excited states with high precision, revealing limits of molecular alignment and evidence of deformation and dissociation.

Contribution

It demonstrates the use of UEDAM combined with FLMS to directly image molecular structures and dynamics in excited states without relying on theoretical models.

Findings

Achieved 0.03 Å precision in imaging CS2 molecules

Identified an upper limit of molecular alignment at sub-ionization laser intensities

Observed structural deformation, dissociation, and ionization at higher laser intensities

Abstract

Imaging the structure of molecules in transient excited states remains a challenge due to the extreme requirements for spatial and temporal resolution. Ultrafast electron diffraction from aligned molecules (UEDAM) provides atomic resolution and allows for the retrieval of structural information without the need to rely on theoretical models. Here we use UEDAM and femtosecond laser mass spectrometry (FLMS) to investigate the dynamics in carbon disulfide (CS2) following the interaction with an intense femtosecond laser pulse. We have retrieved images of ground state and excited molecules with 0.03 {\AA} precision. We have observed that the degree of alignment reaches an upper limit at laser intensities below the ionization threshold, and found evidence of structural deformation, dissociation, and ionization at higher laser intensities.