The adsorption characteristics of rare earth ion La(Ⅲ) on Yunnan bowl tea surface from aqueous solution and effects of various surfactants on the adsorption were studied. It was found that Yunnan bowl tea can adsorb ...The adsorption characteristics of rare earth ion La(Ⅲ) on Yunnan bowl tea surface from aqueous solution and effects of various surfactants on the adsorption were studied. It was found that Yunnan bowl tea can adsorb strongly La(Ⅲ) and pH may affect drastically the adsorption amount of La(Ⅲ). The adsorption law of La(Ⅲ) on Yunnan bowl tea surface follows the Langmuir equation. The maximum adsorption amount of La(Ⅲ) can reach 15 mg·g (-1). A comprehensive adsorption model is suggested according to the experimental results.展开更多
Eu（Ⅲ） complexes with chosen Keggin polyoxomatalates, POM, containing organic counter cations （tetrabutylarnmonium, tetrabutylphosphonium, triphenylethylphosphonium）, were synthesized, and their photophysical prop...Eu（Ⅲ） complexes with chosen Keggin polyoxomatalates, POM, containing organic counter cations （tetrabutylarnmonium, tetrabutylphosphonium, triphenylethylphosphonium）, were synthesized, and their photophysical properties were studied. The synthesized complexes had the general formula of XnH5-n[EuSiW11O39], formulated based on the results of elemental and thermogravimetric analysis and FTIR spectroscopy. The photophysical properties of the obtained compounds were investigated using photoluminescence and electrochemiluminescence, ECL, methods in solutions and solids. The most intense luminescence of Eu（Ⅲ） was observed for the complexes with tetrabutylarnmonium cations. After the addition of phenanthroline to the XnH5-n[EuSiW11O39] solutions, a large increase in the Eu（Ⅲ） luminescence intensity and a lengthening of its luminescence lifetime were observed as a result of the formation of ternary complexes. Attempts to apply ECL as a method of light emission by generating species capable of forming excited states in Ln/POMs, i.e., Tb（Ⅲ） and Eu（Ⅲ） in the Na9EuW10O36 and Na9TbW10O36 complexes, were made. The influence of the POM complexes on the ECL was also tested using the Tb/EDDHA （EDDA=ethylenediamine di（o-hydroxyphenylacetic acid）） complex, which is effective in generating ECL.展开更多
The title complexes （LnL3 （HL） （H2O） ]2· 2EtOH·2H2O （Ln= Nd （1）, La （2）, HL=adamantanecarboxylic acid） were prepared and determined by single-crystal X-ray diffraction. Both complexes crystallize ...The title complexes （LnL3 （HL） （H2O） ]2· 2EtOH·2H2O （Ln= Nd （1）, La （2）, HL=adamantanecarboxylic acid） were prepared and determined by single-crystal X-ray diffraction. Both complexes crystallize in triclinic system with space group P 1^-, cell parameters are： complex （1） a = 1.0556（2） nm, b =1.4913（3） nm, c = 1.4920（3） nm, a = 106.26 （3）°, β=93.51（3）°, γ=97.23（3）°, V=2.2253 （5） nm^3, Dcal=1.409 g · cm^-3, Z = I , F （ 000 ） = 990, μ（Mo Kα） = 1. 225 mm^-1, M, = 1884.50; complex （2） a = 1.0453（2） nm, b = 1.4971（3）nm, c = 1.5052（3） nm, α = 106.07（3）°, β =93.58 （3）°, γ=97.56（3）°, V=2.2391（5）nm^3, Dcal= 1.397 g·cm^-3, Z = 1, F（000） =984, μ（Mo Kα） = 1.015 mm^-1, Mr= 1877.88. The final R and wR are 0. 0396 and 0. 1062 for 8589 （1 ≥ 2σ （I）） observed reflections for complex （1）, 0.0505 and 0. 1344 for 8417 （ 1 ≥ 2σ （1） ） observed reflections for complex （2）, respectively. The crystals are consisted of a binuelear molecule. The coordination geometry of the Ln（ Ⅲ ） ion can be described as trieapped trigonal prism.展开更多
The present paper proposes a new method of spectrophotometry based on linear combination of multiwavelength data by means of selecting a set of properly weighted coefficients and combination methods. It is clear that ...The present paper proposes a new method of spectrophotometry based on linear combination of multiwavelength data by means of selecting a set of properly weighted coefficients and combination methods. It is clear that the weighted combination absorbance attained is only in direct proportion to the concentration of the analysed component and independent of coexisting interferents.The accuracy of the analytical results is improved greatly for the analysis of light rare earths with the coexistence of heavy rare earths.The analyti- cal error from the reagent blank and co-coloration of light and heavy rare earths have also been overcome. The greatly improved linearity and additivity of absorbance are obtained.展开更多
文摘The adsorption characteristics of rare earth ion La(Ⅲ) on Yunnan bowl tea surface from aqueous solution and effects of various surfactants on the adsorption were studied. It was found that Yunnan bowl tea can adsorb strongly La(Ⅲ) and pH may affect drastically the adsorption amount of La(Ⅲ). The adsorption law of La(Ⅲ) on Yunnan bowl tea surface follows the Langmuir equation. The maximum adsorption amount of La(Ⅲ) can reach 15 mg·g (-1). A comprehensive adsorption model is suggested according to the experimental results.
文摘Eu（Ⅲ） complexes with chosen Keggin polyoxomatalates, POM, containing organic counter cations （tetrabutylarnmonium, tetrabutylphosphonium, triphenylethylphosphonium）, were synthesized, and their photophysical properties were studied. The synthesized complexes had the general formula of XnH5-n[EuSiW11O39], formulated based on the results of elemental and thermogravimetric analysis and FTIR spectroscopy. The photophysical properties of the obtained compounds were investigated using photoluminescence and electrochemiluminescence, ECL, methods in solutions and solids. The most intense luminescence of Eu（Ⅲ） was observed for the complexes with tetrabutylarnmonium cations. After the addition of phenanthroline to the XnH5-n[EuSiW11O39] solutions, a large increase in the Eu（Ⅲ） luminescence intensity and a lengthening of its luminescence lifetime were observed as a result of the formation of ternary complexes. Attempts to apply ECL as a method of light emission by generating species capable of forming excited states in Ln/POMs, i.e., Tb（Ⅲ） and Eu（Ⅲ） in the Na9EuW10O36 and Na9TbW10O36 complexes, were made. The influence of the POM complexes on the ECL was also tested using the Tb/EDDHA （EDDA=ethylenediamine di（o-hydroxyphenylacetic acid）） complex, which is effective in generating ECL.
文摘The title complexes （LnL3 （HL） （H2O） ]2· 2EtOH·2H2O （Ln= Nd （1）, La （2）, HL=adamantanecarboxylic acid） were prepared and determined by single-crystal X-ray diffraction. Both complexes crystallize in triclinic system with space group P 1^-, cell parameters are： complex （1） a = 1.0556（2） nm, b =1.4913（3） nm, c = 1.4920（3） nm, a = 106.26 （3）°, β=93.51（3）°, γ=97.23（3）°, V=2.2253 （5） nm^3, Dcal=1.409 g · cm^-3, Z = I , F （ 000 ） = 990, μ（Mo Kα） = 1. 225 mm^-1, M, = 1884.50; complex （2） a = 1.0453（2） nm, b = 1.4971（3）nm, c = 1.5052（3） nm, α = 106.07（3）°, β =93.58 （3）°, γ=97.56（3）°, V=2.2391（5）nm^3, Dcal= 1.397 g·cm^-3, Z = 1, F（000） =984, μ（Mo Kα） = 1.015 mm^-1, Mr= 1877.88. The final R and wR are 0. 0396 and 0. 1062 for 8589 （1 ≥ 2σ （I）） observed reflections for complex （1）, 0.0505 and 0. 1344 for 8417 （ 1 ≥ 2σ （1） ） observed reflections for complex （2）, respectively. The crystals are consisted of a binuelear molecule. The coordination geometry of the Ln（ Ⅲ ） ion can be described as trieapped trigonal prism.
文摘The present paper proposes a new method of spectrophotometry based on linear combination of multiwavelength data by means of selecting a set of properly weighted coefficients and combination methods. It is clear that the weighted combination absorbance attained is only in direct proportion to the concentration of the analysed component and independent of coexisting interferents.The accuracy of the analytical results is improved greatly for the analysis of light rare earths with the coexistence of heavy rare earths.The analyti- cal error from the reagent blank and co-coloration of light and heavy rare earths have also been overcome. The greatly improved linearity and additivity of absorbance are obtained.
