Primary radical ions in irradiated carbonates

Area of Science:

• Physical Chemistry
• Radiation Chemistry
• Materials Science

Background:

• Liquid carbonates are used in various applications, but their behavior under high-energy radiation is not fully understood.
• Primary radical ionic species play a critical role in radiation-induced chemical transformations.

Purpose of the Study:

• To investigate the nature and formation of primary radical ionic species in liquid carbonates after high-energy radiation exposure.
• To elucidate the structure and lifetime of these transient species using spectroscopic and computational methods.

Main Methods:

• Radiation-induced fluorescence intensity decay measurements.
• Application of external magnetic and electric fields to probe charge and spin dynamics.
• Quantum chemical calculations for structural and electronic analysis.

Main Results:

• Observed rapid solvent ionization followed by the formation of long-lived positive charge and unpaired electron spin carriers.
• Identified these carriers as complexes of two carbonate molecules, with charge/spin density on carbonyl groups.
• Determined diethyl carbonate complex formation depends on molecular conformation and proton transfer.
• Found evidence for mobile solvent radical anions in low-polarity carbonates.

Conclusions:

• The study reveals the formation of stable, complex radical ionic species in liquid carbonates under radiation.
• These findings provide fundamental insights into the radiation chemistry of carbonates and their potential applications.