(633f) First-Principles Simulations On High-Pressure Bonding Pathways for CO2 Condensed Phases

Anguang Hu and Fan Zhang

Defense R&D Canada-Suffield, Canada, Box 4000, Stn. Main Medicine Hat, Alberta, T1A 8K6 Canada

A chemical reaction is a process that leads to the transformation from its reactant to the final product, usually in stepwise through reactive intermediates. Although reactive intermediates may be highly energetic but shortly lived, they can help understanding of a detailed chemical reaction process towards the products. Thus, the fundamental knowledge of reactive intermediates in combination with chemical kinetics, thermodynamics and spectroscopy has led to rational design of synthetic targets in the field of organic chemistry. The design of synthesis targets becomes much more complicated in high-pressure chemical reactions due to challenges in probing chemical reactions. Under high-pressure/high-temperature conditions, technologies for temporally-controlled pressurization are critical for chemical bond breaking/forming reaction steps. In this paper, first-principles simulations are applied to determine appropriate molecular intermediate states along the reaction paths. High-pressure bonding pathways for CO₂ condensed phases were then established. The simulated high-pressure bonding pathways not only provided microscopic mechanisms on how atoms and electrons move during the course of transformations, but also revealed that the bonding group configurations of molecular intermediates dictate the stereochemistry of the final products and govern bond breaking and forming along the path of a cell volume collapse for a chemical transformation.