Exploring a Substitution Strategy to Ethylene Oxide for CO₂ Sequestration and Catalytic Conversion: A Theoretical...

Area of Science:

• Computational Chemistry
• Materials Science
• Green Chemistry

Background:

• Ethylene oxide is a key industrial chemical.
• Carbon dioxide (CO2) utilization remains a significant challenge in green chemistry.
• Catalytic and non-catalytic methods for CO2 cycloaddition are actively researched.

Purpose of the Study:

• To investigate the effect of amino substituents on ethylene oxide for CO2 cycloaddition.
• To elucidate the mechanism behind the reduced reaction barrier.
• To explore the potential of modified ethylene oxide in CO2 fixation and conversion.

Main Methods:

• Density Functional Theory (DFT) calculations.
• Analysis of local charges, frontier orbitals, and electron transfer.
• Distortion/Interaction-Activation Strain Model (D/I-ASM) simulations.

Main Results:

• Amino-substituted ethylene oxides, particularly -N(CH3)2-monosubstituted ethylene oxide (NEO), dramatically reduce the CO2 cycloaddition barrier from 69.5 to 22.1 kcal/mol.
• The reduction in barrier height is attributed to decreased activation strain and increased intermolecular interaction.
• NEO facilitates CO2 sequestration and subsequent conversion to dimethyl carbonate and N,N'-dimethylurea with catalysts like TBD.

Conclusions:

• Amino functionalization of ethylene oxide offers a promising pathway for efficient CO2 capture and utilization under mild conditions.
• NEO serves as an effective substrate for CO2 fixation and conversion, potentially applicable to epoxy resins.
• This research paves the way for incorporating amino functionalities into epoxides for sustainable chemical synthesis.