Ultrafast isolated molecule imaging without crystallization.

Area of Science:

• Molecular imaging
• Atomic resolution
• Non-crystallized molecules

Background:

• Crystallography is the standard for atomic structure determination but fails for non-crystallized molecules.
• Existing techniques like serial femtosecond crystallography require nanocrystals for sufficient signal.
• Imaging single isolated molecules faces challenges due to weak scattering signals.

Purpose of the Study:

• To develop a method for determining the atomic structure of non-crystallized molecules.
• To enable structural analysis of molecules that do not form crystals.
• To advance coherent diffraction imaging techniques for molecular structure retrieval.

Main Methods:

• Utilizing a femtosecond laser pulse train to transiently align an ensemble of isolated molecules.
• Employing a precisely timed ultrashort relativistic electron beam to record diffraction patterns.
• Applying coherent diffraction imaging to reconstruct molecular structure from diffraction data.

Main Results:

• Achieved high-level transient alignment of molecules for approximately 100 femtoseconds.
• Recorded diffraction patterns from aligned molecules using a table-top instrument.
• Successfully reconstructed the atomic distribution of CO2 molecules with atomic resolution.

Conclusions:

• This method represents a significant advancement toward imaging non-crystallized molecules at atomic resolution.
• The technique opens new avenues for studying and controlling molecular dynamics in the molecular frame.
• Provides insights into molecular structures and dynamics previously inaccessible with randomly oriented molecules.