Yamamoto Akira, Liu Xueshi, Arashiba Kazuya, Konomi Asuka, Tanaka Hiromasa, Yoshizawa Kazunari, Nishibayashi Yoshiaki, Yoshida Hisao
Department of Interdisciplinary Environment, Graduate School of Human and Environmental Studies, Kyoto University, Yoshida Nihonmatsu-cho, Sakyo-ku, Kyoto606-8501, Japan.
Elements Strategy Initiative for Catalysts & Batteries (ESICB), Kyoto University, Kyotodaigaku Katsura, Nishikyo-ku, Kyoto615-8520, Japan.
Inorg Chem. 2023 Apr 10;62(14):5348-5356. doi: 10.1021/acs.inorgchem.2c03752. Epub 2023 Feb 2.
Chemoselective reductive conversion of organic and inorganic compounds has been developed by the combination of samarium(II) diiodide (SmI) and water. Despite the extensive previous studies to elucidate the role of water in the reactivity of SmI, the direct structural data of the reactive Sm-water complexes, SmI(HO), in an organic solvent-water mixture have not been reported experimentally so far. Herein, we performed the structure analysis of the Sm-water complex in tetrahydrofuran (THF) in the presence of water by in situ X-ray absorption spectroscopy using high-energy X-rays (Sm K-edge, 46.8 keV). The analysis revealed the dissociation of the Sm-I bonds in the presence of ≥ eight equivalents of water in the THF-water mixture. The origin of the peak shift in the UV/visible absorption spectra after the addition of water into SmI/THF solution was proposed based on electron transitions simulated with time-dependent density-functional-theory calculations using optimized structures in THF or water. The obtained structural information provides the fundamental insights for elucidating the reactivity and chemoselectivity in the Sm-water complex system.
通过二碘化钐（SmI）与水的组合，已开发出有机和无机化合物的化学选择性还原转化方法。尽管此前进行了大量研究以阐明水在SmI反应性中的作用，但到目前为止，尚未通过实验报道在有机溶剂 - 水混合物中活性Sm - 水络合物SmI(HO)的直接结构数据。在此，我们通过使用高能X射线（Sm K边，46.8 keV）的原位X射线吸收光谱，对四氢呋喃（THF）中存在水时的Sm - 水络合物进行了结构分析。分析表明，在THF - 水混合物中存在≥八当量水的情况下，Sm - I键发生解离。基于使用THF或水中优化结构的含时密度泛函理论计算模拟的电子跃迁，提出了向SmI/THF溶液中加水后紫外/可见吸收光谱中峰位移的起源。所获得的结构信息为阐明Sm - 水络合物体系中的反应性和化学选择性提供了基本见解。
