Hashikawa Yoshifumi, Hasegawa Shota, Murata Yasujiro
Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan.
Angew Chem Int Ed Engl. 2021 Feb 8;60(6):2866-2870. doi: 10.1002/anie.202012538. Epub 2020 Dec 15.
[60]Fullerene-based carbon nanopores were synthesized to enable the placement of two molecules of nitric oxide (NO) at an accurate distance from one another. A linear orientation of the two NO molecules inside the assembled nanopores was confirmed crystallographically. Theoretical studies suggested possible free rotation inside the carbon nanopore, while the two conformations of NO in which its long axis was oriented toward the orifice of the nanopore were predicted to be dominant. The paramagnetic shifts caused by NO showed a major contribution from the Fermi contact mechanism. The Solomon-Bloembergen theory was found to describe well the paramagnetic relaxation enhancement of a water molecule in a paired nanopore even under equilibrium as a result of fixing of the NO molecule with a distance of approximately 12 Å, thus demonstrating a long-range bimolecular magnetic interaction.
[60]合成了基于富勒烯的碳纳米孔，以使两个一氧化氮（NO）分子能够以精确的距离相互排列。通过晶体学证实了组装的纳米孔内两个NO分子的线性取向。理论研究表明，碳纳米孔内可能存在自由旋转，而预测NO的长轴朝向纳米孔孔口的两种构象占主导地位。由NO引起的顺磁位移显示出费米接触机制的主要贡献。结果发现，所罗门-布洛姆伯根理论能够很好地描述即使在平衡状态下，由于NO分子以约12Å的距离固定，配对纳米孔中水分子的顺磁弛豫增强，从而证明了远程双分子磁相互作用。
