Radical-molecule reaction C(3P) + C3H6: mechanistic study.

Area of Science:

• Chemical Kinetics
• Theoretical Chemistry
• Quantum Chemistry

Background:

• The reaction between ground-state atomic carbon (C(3P)) and propylene (C3H6) is crucial for understanding complex chemical processes.
• Investigating the potential energy surface is essential for elucidating reaction mechanisms and kinetics.

Purpose of the Study:

• To explore the complex triplet potential energy surface for the C(3P) + C3H6 reaction.
• To identify and analyze various reaction pathways and intermediates.
• To provide insights into the reaction's rate and potential experimental validation.

Main Methods:

• Computational chemistry methods including B3LYP/6-311G(d,p), QCISD/6-311G(d,p), and G3B3 (single-point) were employed.
• Exploration of various reaction pathways, including addition, ring-opening, and bond cleavage processes.
• Analysis of intermediates and transition states to determine the most feasible reaction routes.

Main Results:

• The reaction initiates with barrierless addition of C(3P) to the C=C bond of C3H6, forming a three-membered ring isomer.
• Ring-opening leads to trans- and cis-isomers, which undergo subsequent C-H or C-C bond ruptures.
• Feasible pathways involve C-H bond rupture (internal or terminal) or C-C bond fission, with comparable contributions.
• A less competitive pathway involves a 1,2-H shift followed by C-C bond rupture.

Conclusions:

• The reaction proceeds rapidly due to low-lying intermediates and transition states, consistent with experimental observations.
• The identified pathways and products offer valuable information for future experimental studies.
• This theoretical investigation provides a detailed understanding of the C(3P) + C3H6 reaction dynamics.