Radical-Radical Reaction Dynamics Probed Using Millimeterwave Spectroscopy: Propargyl + NH₂/ND₂

Area of Science:

• Chemical Kinetics
• Astrochemistry
• Combustion Chemistry

Background:

• Radical-radical reactions are crucial in gas-phase chemistry.
• Understanding the propargyl + amino radical reaction is vital for astrochemical and combustion models.

Purpose of the Study:

• To elucidate the complex reaction dynamics and product branching ratios of the C3H3 + NH2/ND2 reaction.
• To investigate the influence of reactant internal energy on reaction outcomes.

Main Methods:

• Utilized chirped-pulse uniform flow millimeterwave (CPUF-mmW) spectroscopy for product detection.
• Employed high-level electronic structure calculations and RRKM theory for theoretical analysis.

Main Results:

• Simultaneously detected multiple reaction products including HCN, HNC, HC3N, DCN, DNC, and DC3N.
• Quantified product branching fractions through spectral intensity analysis.
• Observed strong dependence of product branching on excess internal energy of reactants.

Conclusions:

• The study provides detailed insights into the reaction mechanism and product distribution.
• Findings are critical for refining astrochemical and combustion chemical models.