A lacunary Keggin-type tungstosilicate dimer-estertin derivative,(C(NH_(2))_(3))_(7)H_(3.5)[(K⊂Ni H_(2)O)_(2)(SnCH_(2)CH_(2)COO)((Ni(H_(2)O))_(0.75)(WO)_(0.25))(Si_(2)W_(18)O_(67))]·6H_(2)O(abbreviated as Si_(2)W...A lacunary Keggin-type tungstosilicate dimer-estertin derivative,(C(NH_(2))_(3))_(7)H_(3.5)[(K⊂Ni H_(2)O)_(2)(SnCH_(2)CH_(2)COO)((Ni(H_(2)O))_(0.75)(WO)_(0.25))(Si_(2)W_(18)O_(67))]·6H_(2)O(abbreviated as Si_(2)W_(18)-Ni-SnRCOO,R=CH_(2)CH_(2)),was synthesized by using the conventional aqueous solution method,and characterized by a series of physical and spectral methods.Single crystal X-ray structural analysis revealed that the polyoxometalate(POM)was a dimeric tungstosilicate-based organic-inorganic hybrid compound,which contained two Ni ions and a cyclic carboxyltin group(SnRCOO).Unexpectedly,the carboxyl-oxygen atom of SnRCOO acted as a bridging oxygen atom belonged to the POM skeleton and connected to NiO_(6)octahedron.The thermal and photocatalytic activities of Si_(2)W_(18)-Ni-SnRCOO were studied.As a homogeneous catalyst,the conversion of cyclohexanol to cyclohexanone was as high as 98%,and the degradation efficiency of 20 mg·L^(-1)RhB reached 88%.The experimental results showed that the introduction of the carboxyethyltin group significantly enhanced the catalytic activity of this type of POM-based catalyst.Additionally,the composite of Si_(2)W_(18)-Ni-SnRCOO and TiO_(2) enabled the catalyst to be recycled,and the photocatalytic efficiency of Si_(2)W_(18)-Ni-SnRCOO/TiO_(2) remained almost unchanged after five cycles.展开更多
基金financially supported by the National Natural Science Foundation of China (21671091 and 21503103)the Startup Project of Doctor Scientific Research from Liaoning Normal University (2023BSL017)
文摘A lacunary Keggin-type tungstosilicate dimer-estertin derivative,(C(NH_(2))_(3))_(7)H_(3.5)[(K⊂Ni H_(2)O)_(2)(SnCH_(2)CH_(2)COO)((Ni(H_(2)O))_(0.75)(WO)_(0.25))(Si_(2)W_(18)O_(67))]·6H_(2)O(abbreviated as Si_(2)W_(18)-Ni-SnRCOO,R=CH_(2)CH_(2)),was synthesized by using the conventional aqueous solution method,and characterized by a series of physical and spectral methods.Single crystal X-ray structural analysis revealed that the polyoxometalate(POM)was a dimeric tungstosilicate-based organic-inorganic hybrid compound,which contained two Ni ions and a cyclic carboxyltin group(SnRCOO).Unexpectedly,the carboxyl-oxygen atom of SnRCOO acted as a bridging oxygen atom belonged to the POM skeleton and connected to NiO_(6)octahedron.The thermal and photocatalytic activities of Si_(2)W_(18)-Ni-SnRCOO were studied.As a homogeneous catalyst,the conversion of cyclohexanol to cyclohexanone was as high as 98%,and the degradation efficiency of 20 mg·L^(-1)RhB reached 88%.The experimental results showed that the introduction of the carboxyethyltin group significantly enhanced the catalytic activity of this type of POM-based catalyst.Additionally,the composite of Si_(2)W_(18)-Ni-SnRCOO and TiO_(2) enabled the catalyst to be recycled,and the photocatalytic efficiency of Si_(2)W_(18)-Ni-SnRCOO/TiO_(2) remained almost unchanged after five cycles.
