Li Huafeng, He Peipei, Wan Rong, Zou Yan, Zhao Xue, Ma Pengtao, Niu Jingyang, Wang Jingping
Henan Key Laboratory of Polyoxometalate Chemistry, College of Chemistry and Chemical Engineering, Henan University, Kaifeng, Henan 475004, China.
Dalton Trans. 2020 Mar 3;49(9):2895-2904. doi: 10.1039/c9dt04616j.
Two ruthenium-containing polyoxometalate-based hybrids (Ru-POMs), KH8[Ru3O(Trz)6Cl3]2[(NaO6)W6(H2O)6(AsW9O33)4]·28H2O (1) and H3[Ru3O(Trz)6Cl3]2[(WO)2W(OH)(AsW9O33)2]·6H2O (2), (Trz = 1,2,4-triazole), were successfully isolated by a one-step hydrothermal method under different acidic conditions and further characterized by single-crystal X-ray diffraction, powder X-ray diffraction (PXRD), IR spectroscopy, electrospray ionization and mass spectrometry (ESI-MS), thermogravimetric (TG) analyses and elemental analyses. Single-crystal X-ray diffraction analyses reveal two polyanions comprised of four/two identical trivacant Keggin-type polyanion building blocks, leading to the formation of tetrameric/dimeric assembly stabilized by additional metal-oxo cores, respectively. ESI-MS shows that the polyanion units [(NaO6)W6(H2O)6(AsW9O33)4]11- and [(WO)2W(OH)(AsW9O33)2]5- are intact in mixed solvent. Moreover, the two heterogeneous catalysts with trinuclear ruthenium cations were further investigated, and 1 was found to exhibit much higher yield (94.1%)/conversion (95.1%) and better selectivity (>99%) towards the oxidation of thioanisole to sulfoxide than 2.
通过一步水热法在不同酸性条件下成功分离出两种含钌的基于多金属氧酸盐的杂化物（Ru-POMs），即KH8[Ru3O(Trz)6Cl3]2[(NaO6)W6(H2O)6(AsW9O33)4]·28H2O（1）和H3[Ru3O(Trz)6Cl3]2[(WO)2W(OH)(AsW9O33)2]·6H2O（2），（Trz = 1,2,4-三唑），并通过单晶X射线衍射、粉末X射线衍射（PXRD）、红外光谱、电喷雾电离和质谱（ESI-MS）、热重（TG）分析以及元素分析对其进行了进一步表征。单晶X射线衍射分析表明，两种聚阴离子分别由四个/两个相同的三缺位Keggin型聚阴离子结构单元组成，分别导致通过额外的金属-氧核稳定形成四聚体/二聚体组装体。ESI-MS表明，聚阴离子单元[(NaO6)W6(H2O)6(AsW9O33)4]11-和[(WO)2W(OH)(AsW9O33)2]5-在混合溶剂中是完整的。此外，对两种含三核钌阳离子的非均相催化剂进行了进一步研究，发现1对苯甲硫醚氧化为亚砜的反应表现出比2更高的产率（94.1%）/转化率（95.1%）和更好的选择性（>99%）。
