Imaging Purely Nuclear Quantum Dynamics in Molecules by Combined X-ray and Electron Diffraction

Area of Science:

• Physical Chemistry
• Chemical Physics
• Ultrafast Spectroscopy

Background:

• Femtochemistry aims to monitor atomic and molecular motion during chemical processes.
• Traditional optical spectroscopy primarily detects electronic properties, not nuclear dynamics.

Purpose of the Study:

• To propose a novel measurement for directly monitoring evolving nuclear wave packets.
• To enable unambiguous real-time imaging of photochemical events.

Main Methods:

• Theoretical study proposing a new measurement technique.
• Utilizing ultrafast gas-phase X-ray and electron diffraction.
• Subtracting diffraction signals to isolate nuclear charge densities.

Main Results:

• Demonstrated isolation of nuclear charge densities during thiophenol photodissociation.
• Successfully tracked nuclear wave packet shape and trajectory.
• Revealed electronic coherences near conical intersections.

Conclusions:

• The proposed method allows direct and unambiguous monitoring of nuclear motion.
• Enables real-time imaging of photochemical dynamics.
• Provides insights into molecular behavior at conical intersections.