Diffractive Imaging of Coherent Nuclear Motion in Isolated Molecules

Area of Science:

• Physical Chemistry
• Chemical Physics
• Molecular Dynamics

Background:

• Understanding molecular reaction dynamics is key to controlling chemical processes.
• Visualizing nuclear wave packet motion in real-time is essential for this understanding.

Purpose of the Study:

• To image the spatial and temporal motion of a nuclear wave packet.
• To demonstrate a novel method for observing molecular reactions at the atomic level.

Main Methods:

• Utilized ultrafast electron diffraction (UED) with relativistic electrons.
• Applied UED to isolated iodine molecules to observe vibrational wave packet motion.
• Achieved high precision (0.07 Å) and temporal resolution (230 fs FWHM).

Main Results:

• Successfully imaged the motion of a vibrational wave packet in iodine molecules.
• Measured the time-varying interatomic distance with high accuracy.
• Demonstrated sensitivity to both the position and shape of the nuclear wave packet.

Conclusions:

• Ultrafast electron diffraction with relativistic electrons is a powerful tool for observing molecular dynamics.
• This method provides unprecedented insight into the real-time behavior of nuclear wave packets.
• Enables future control over photoinduced chemical reactions by understanding their fundamental motion.