Department of Chemistry, Faculty of Science, New Valley University, Kharga 72511, Egypt.
Combustion Chemistry Centre, School of Chemistry, Ryan Institute, MaREI, National University of Ireland Galway, Galway H91 TK33, Ireland.
J Phys Chem A. 2023 Jan 12;127(1):29-37. doi: 10.1021/acs.jpca.2c05931. Epub 2023 Jan 3.
The current project aims to apply the virtues of minimalism to examine the catalytic ability of commercially organic compounds of small chemical structures to catalyze the coupling reaction between carbon dioxide and propylene oxide (PO) under mild conditions. The proposed catalysts are pyridinium iodide (), 2-hydroxypyridinium iodide (), and piperidinium iodide (), where their structure is based on cooperative acidic and nucleophilic motifs. The quantum chemistry model, M062X-D3/def2-TZVP//M062X-D3/def2-SVPP, was used to understand the reaction mechanism and the catalytic performance. Since the coupling reaction was performed under excess PO, we proposed that PO serves as a reactant and solvent. Therefore, calculations were performed in gas and liquid phases for comparison. The findings indicated that the rate-determining step depends on the chemical structure of the catalyst and whether the phase is a gas or liquid phase. In general, modeling in the liquid phase produces potential energy surfaces of lower energy barriers. The noncovalent interactions reflect the role of hydrogen bonding in controlling the kinetic behavior of the coupling reaction. Based on the finding, catalyst is the best candidate for transforming CO into cyclic carbonates.
本项目旨在应用简约主义的优点，研究商业有机化合物的小化学结构在温和条件下催化二氧化碳与环氧丙烷（PO）偶联反应的催化能力。所提出的催化剂为碘化吡啶（）、2-羟基吡啶碘（）和碘化哌啶（），其结构基于协同酸性和亲核性基序。使用量子化学模型 M062X-D3/def2-TZVP//M062X-D3/def2-SVPP 来理解反应机制和催化性能。由于偶联反应是在过量 PO 下进行的，我们假设 PO 既是反应物又是溶剂。因此，在气相和液相中进行了计算以进行比较。结果表明，速率决定步骤取决于催化剂的化学结构以及相是气相还是液相。一般来说，在液相中的建模会产生能量势垒较低的势能面。非共价相互作用反映了氢键在控制偶联反应动力学行为中的作用。基于这一发现，催化剂 是将 CO 转化为环状碳酸酯的最佳候选物。
