Zhu Chengxu, Surendran Adarsh Koovakattil, D'Agostino Carmine, Roithová Jana, de Visser Sam P
Manchester Institute of Biotechnology, The University of Manchester, 131 Princess Street, Manchester M1 7DN, UK.
Department of Chemical Engineering, The University of Manchester, Oxford Road, Manchester M13 9PL, UK.
Dalton Trans. 2025 Mar 17;54(12):4918-4926. doi: 10.1039/d5dt00119f.
With increasing carbon dioxide concentrations in the atmosphere, the utilization and conversion of CO into valuable materials is an important goal. In recent years, evidence has emerged of low-valent iron-porphyrin complexes able to bind CO and reduce it to carbon monoxide and water. To find out how the porphyrin scaffold and second coordination sphere influence the CO reduction on iron-porphyrin complexes, we study the structure, electronic and redox properties of a novel crown-ether appended porphyrin complex with cation (K) binding site. Cyclic voltammetry studies show that the K binding site does not change the Fe and Fe redox potentials of the complexes. Subsequently, density functional theory calculations were performed on the catalytic cycle of CO reduction on the K-bound crown-ether appended iron-porphyrin complex. The work shows that proton-donors such as acetic acid bind the K strongly and can assist with efficient and fast proton transfer that leads to the conversion of CO to CO and water. In agreement with experiment, the calculations show little perturbations of the redox potentials upon binding K to the crown-ether scaffold.
随着大气中二氧化碳浓度的增加，将一氧化碳转化为有价值的物质是一个重要目标。近年来，有证据表明低价铁卟啉配合物能够结合一氧化碳并将其还原为一氧化碳和水。为了弄清楚卟啉支架和第二配位层如何影响铁卟啉配合物上的一氧化碳还原反应，我们研究了一种带有阳离子（K）结合位点的新型冠醚连接卟啉配合物的结构、电子和氧化还原性质。循环伏安法研究表明，K结合位点不会改变配合物的铁（Ⅱ）和铁（Ⅲ）氧化还原电位。随后，对结合K的冠醚连接铁卟啉配合物上一氧化碳还原的催化循环进行了密度泛函理论计算。研究表明，乙酸等质子供体与K强烈结合，并能协助高效快速的质子转移，从而导致一氧化碳转化为一氧化碳和水。与实验结果一致，计算结果表明，将K结合到冠醚支架上时，氧化还原电位几乎没有扰动。
