理论研究二氧化碳在有机吸收剂1，3-二苯胍中的氢键相互作用

如今碳捕获和储存技术已得到了迅速发展以减少对环境的二氧化碳排放. 研究发现胺基有机分子溶剂能有效地吸收二氧化碳，并通过氢键和二氧化碳形成的碳酸氢盐相互作用. 最近，实验报道了一种1，3-二苯基胍溶液，在室温条件下能捕获环境中的二氧化碳并将其转化为有价值的化学品. 然而，1，3-二苯基胍分子在溶液状态下如何与二氧化碳相互作用的机理仍不清楚. 在这项工作中，利用分子动力学方法模拟研究了溶液相中1，3-二苯基胍分子与二氧化碳的复杂作用细节. 模拟结果表明，质子化的1，3-二苯基胍分子和碳酸氢根离子倾向通过不同的双氢键模式作用形成稳定的复合物. 精确的密度泛函方法计算表明，这些双氢键复合物在热力学上相当稳定. 本研究有助于理解溶液相中1，3-二苯基胍分子中催化转化二氧化碳的机理.

Theoretical Study of Hydrogen-Bond Interactions of CO2 in Organic Absorbent 1,3-Diphenylguanidine

Carbon capture and storage technology have been rapidly developed to reduce the carbon dioxide (CO₂) emission into the environment. It has been found that the amine-based organic molecules could absorb CO₂ efficiently and form the bicarbonate salts through hydrogen-bond (H-bond) interactions. Recently, the aqueous 1,3-diphenylguanidine (DPG) solution was developed to trap and convert CO₂ to valuable chemicals under ambient conditions. However, how the DPG molecules interact with CO₂ in an aqueous solution remains unclear. In this work, we perform molecular dynamics simulations to explore the atomistic details of CO₂ in the aqueous DPG. The simulated results reveal that the protonated DPGH⁺ and the bicarbonate anions prefer to form complexes through different H-bond patterns. These double H-bonds are quite stable in thermodynamics, as indicated from the accurate density functional theory calculations. This study is helpful to understand the catalytic mechanism of CO₂ conversion in the aqueous DPG.