In this study, the kinetics and mechanism of the iridium（ Ⅲ ） -catalyzed oxidation of ethanol amine（EAN） by cerium（Ⅳ） in a sulfuric acid medium was investigated using titrimetric technique of redox in a temper...In this study, the kinetics and mechanism of the iridium（ Ⅲ ） -catalyzed oxidation of ethanol amine（EAN） by cerium（Ⅳ） in a sulfuric acid medium was investigated using titrimetric technique of redox in a temperature range of 298--313 K. It was found that the reaction is of first order with respect to Ce（ Ⅳ ） and It（ Ⅲ ）, and a positive fractional order with respect to EAN. It was also found that the pseudo-first-order （ [EAN ] 〉〉 [ Ce （ Ⅳ） ] ） rate constant koba decreases with the increase of [ H^＋ ] and [ HSO^-4 ]. Under the protection of nitrogen gas, the reaction system can initiate the polymerization of acrylonitrile, indicating the generation of free radicals. On the basis of the experimental results, a suitable mechanism was proposed. From the dependence of koba on the concentration of hydrogen sulfate, Ce（SO4）2 was found to be the kinetically active species. The rate constants of the rote-determining step together with the activation parameters were evaluated.展开更多
合成了一种铱配合物[Ir(N4)(MDFPPM)2](MDFPPM=4,6-二甲基-2-(2,4-二氟苯基)嘧啶,N4=5-(2-吡啶基)-1H-四唑),并利用X射线单晶衍射仪测定了该化合物的2种晶体结构。通过紫外-可见(UV-Vis)吸收光谱、荧光光谱、循环伏安法及含时密度泛函理...合成了一种铱配合物[Ir(N4)(MDFPPM)2](MDFPPM=4,6-二甲基-2-(2,4-二氟苯基)嘧啶,N4=5-(2-吡啶基)-1H-四唑),并利用X射线单晶衍射仪测定了该化合物的2种晶体结构。通过紫外-可见(UV-Vis)吸收光谱、荧光光谱、循环伏安法及含时密度泛函理论(TD-DFT)对其光物理性能及能级结构进行了研究。结果表明:2个晶体的空间构型均为单斜,空间群均为P21/c;Ir(N4)(MDFPPM)2的最高占据轨道(HOMO)主要定域于金属Ir(Ⅲ)和配体MDFPPM的苯环上,最低未占有轨道(LUMO)主要定域于配体MDFPPM的嘧啶环上;配合物Ir(N4)(MDFPPM)2的HOMO和LUMO能级分别为-5.98和-3.22 e V;Ir(N4)(MDFPPM)2在77 K乙腈溶液中的发射峰波长在449、480和513 nm,CIEx,y色度坐标为(0.15,0.23),是一种潜在的蓝色磷光材料。展开更多
基金Supported by the Doctoral Foundation of Education Department of Hebei Province(NoB2004205) Hebei University Re-search Foundation(No2003Z09)
文摘In this study, the kinetics and mechanism of the iridium（ Ⅲ ） -catalyzed oxidation of ethanol amine（EAN） by cerium（Ⅳ） in a sulfuric acid medium was investigated using titrimetric technique of redox in a temperature range of 298--313 K. It was found that the reaction is of first order with respect to Ce（ Ⅳ ） and It（ Ⅲ ）, and a positive fractional order with respect to EAN. It was also found that the pseudo-first-order （ [EAN ] 〉〉 [ Ce （ Ⅳ） ] ） rate constant koba decreases with the increase of [ H^＋ ] and [ HSO^-4 ]. Under the protection of nitrogen gas, the reaction system can initiate the polymerization of acrylonitrile, indicating the generation of free radicals. On the basis of the experimental results, a suitable mechanism was proposed. From the dependence of koba on the concentration of hydrogen sulfate, Ce（SO4）2 was found to be the kinetically active species. The rate constants of the rote-determining step together with the activation parameters were evaluated.
文摘合成了一种铱配合物[Ir(N4)(MDFPPM)2](MDFPPM=4,6-二甲基-2-(2,4-二氟苯基)嘧啶,N4=5-(2-吡啶基)-1H-四唑),并利用X射线单晶衍射仪测定了该化合物的2种晶体结构。通过紫外-可见(UV-Vis)吸收光谱、荧光光谱、循环伏安法及含时密度泛函理论(TD-DFT)对其光物理性能及能级结构进行了研究。结果表明:2个晶体的空间构型均为单斜,空间群均为P21/c;Ir(N4)(MDFPPM)2的最高占据轨道(HOMO)主要定域于金属Ir(Ⅲ)和配体MDFPPM的苯环上,最低未占有轨道(LUMO)主要定域于配体MDFPPM的嘧啶环上;配合物Ir(N4)(MDFPPM)2的HOMO和LUMO能级分别为-5.98和-3.22 e V;Ir(N4)(MDFPPM)2在77 K乙腈溶液中的发射峰波长在449、480和513 nm,CIEx,y色度坐标为(0.15,0.23),是一种潜在的蓝色磷光材料。
