Universal crossed beam imaging studies of polyatomic reaction dynamics

Area of Science:

• Chemical Physics
• Molecular Dynamics
• Quantum Chemistry

Background:

• High-level quantum calculations and laser technology enable detailed molecular collision dynamics studies.
• Studying larger molecules ( > 6 atoms) is challenging due to limited spectroscopic data and high computational costs.
• Larger systems can exhibit novel reactivity not seen in smaller models.

Purpose of the Study:

• To adapt advanced techniques for studying bimolecular reaction dynamics of intermediate and large-sized molecules.
• To investigate chemical dynamics of oxygen/chlorine reactions with specific organic compounds.
• To demonstrate a new approach for revealing complex reaction mechanisms in larger systems.

Main Methods:

• Utilized soft vacuum ultraviolet photoionization at 157 nm as a universal probe.
• Employed crossed beams and DC slice velocity map ion imaging.
• Supported experimental findings with high-level ab initio calculations.

Main Results:

• Detected polyatomic radical products from hydrogen abstraction using 157 nm photoionization.
• Analyzed translational energy and angular information from ion images to understand collision dynamics.
• Identified direct abstraction, addition-elimination, roaming dynamics, and intersystem crossing pathways.

Conclusions:

• The combined technique is powerful for studying reaction dynamics in larger molecular systems.
• Novel aspects of reactivity, including roaming and intersystem crossing, were revealed.
• This approach overcomes limitations in studying complex chemical reactions.