Site-dependent nuclear dynamics in core-excited butadiene

Area of Science:

• Physical Chemistry
• Molecular Physics
• Quantum Chemistry

Background:

• Core-hole localization influences molecular fragmentation dynamics.
• Understanding electronic decay and nuclear dynamics competition is crucial for molecular memory retention.

Purpose of the Study:

• Investigate core-hole localization effects at different carbon sites in 1,3 trans butadiene.
• Determine how site-specific core-hole vacancies impact molecular fragmentation pathways.

Main Methods:

• Selective excitation of C 1s electrons to π* orbitals using synchrotron radiation.
• Analysis of molecular fragmentation patterns resulting from core-hole creation at different carbon sites.

Main Results:

• Preferential bond breaking observed for core holes localized at terminal carbon sites.
• Weak localization signature for core holes at central carbon sites, attributed to out-of-plane vibrations.
• Statistical proton evaporation identified as a fragmentation pathway for central core holes.

Conclusions:

• Molecular fragmentation is sensitive to the initial site of core-hole localization.
• Nuclear dynamics, particularly vibrations, play a significant role in memory loss for central core holes.
• Site-specific electronic and nuclear dynamics govern the fate of core-hole excitations in molecules.