The novel europium complex Eu3（dpa dioxide）4·（CF3COO）5·H2O （dpa dioxide = di-2-pyridylamine N,N＇-dioxide） was prepared by the reaction of Eu（CF3CO2）3 with Dpa dioxide in acetonitrile under 95 ℃ and...The novel europium complex Eu3（dpa dioxide）4·（CF3COO）5·H2O （dpa dioxide = di-2-pyridylamine N,N＇-dioxide） was prepared by the reaction of Eu（CF3CO2）3 with Dpa dioxide in acetonitrile under 95 ℃ and determined by X-ray single-crystal diffraction. The crystal belongs to monoclinic system, space group C2/c with a = 41.632（8）, b = 14.662（3）, c = 23.300（4）A,β= 100.862（5）°, Z = 8, D = 1.775 g/cm^3, V = 13968（4）A^3, F（000） = 7232, the final R = 0.0464 and wR = 0.1168. In this tri-nuclear complex, each europium（Ⅲ） is nine-coordinated to adopt an unequal sphere geometry.展开更多
The present study is focused on the influence of a routine step, washing, following the preparation of calcined rare earth exchanged Y zeolite, on its hydrothermal stability. The hydrothermal stability of REY products...The present study is focused on the influence of a routine step, washing, following the preparation of calcined rare earth exchanged Y zeolite, on its hydrothermal stability. The hydrothermal stability of REY products, which were washed by different reagents, was observed and characterized by XRD, ICP, NMR, etc. The results reveal that the amount and the chemical type of the acidic media used for washing can significantly influence the content of remaining non-framework aluminum (NFA) and consequently further affect the hydrothermal stability of the washed REY products. The content of remaining non-framework aluminum can be well correlated with the crystallinity of REY products.展开更多
An anomalous enhancement of fluorescence of carbon dots （CDs） was observed via lanthanum （La） doping. La-doped CDs （La-CDs） were prepared through microwave pyrolysis within 4 min. With La^3＋ doping, the emissio...An anomalous enhancement of fluorescence of carbon dots （CDs） was observed via lanthanum （La） doping. La-doped CDs （La-CDs） were prepared through microwave pyrolysis within 4 min. With La^3＋ doping, the emission band shifted from blue to green although LaB＋ is non-fluorescent. The quantum yield and fluorescence lifetime improved by about 20% and 35%, respectively. All experiment results indicate that La^3＋ doping is an effective way to tune fluorescence and improve the performance of CDs. Another unique attribute of La-CDs is high sensitivity to Fe^3＋. The La-CD-based fluorescence probe was established and used for sensitive and selective detection of Fe^3＋ with a limit of detection of 91 nmol/L. The proposed fluorescence probe also was successfully employed to visualize intracellular Fe^3＋ in live HeLa cells through cell imaging. It was also shown that yttrium exhibited the same fluorescence enhancement effect as La. The results may provide a new route for preparing CDs with special properties.展开更多
基金This work was supported by the Natural Science Foundation of Jiangxi Province (No. 0320026 and 0520036)
文摘The novel europium complex Eu3（dpa dioxide）4·（CF3COO）5·H2O （dpa dioxide = di-2-pyridylamine N,N＇-dioxide） was prepared by the reaction of Eu（CF3CO2）3 with Dpa dioxide in acetonitrile under 95 ℃ and determined by X-ray single-crystal diffraction. The crystal belongs to monoclinic system, space group C2/c with a = 41.632（8）, b = 14.662（3）, c = 23.300（4）A,β= 100.862（5）°, Z = 8, D = 1.775 g/cm^3, V = 13968（4）A^3, F（000） = 7232, the final R = 0.0464 and wR = 0.1168. In this tri-nuclear complex, each europium（Ⅲ） is nine-coordinated to adopt an unequal sphere geometry.
文摘The present study is focused on the influence of a routine step, washing, following the preparation of calcined rare earth exchanged Y zeolite, on its hydrothermal stability. The hydrothermal stability of REY products, which were washed by different reagents, was observed and characterized by XRD, ICP, NMR, etc. The results reveal that the amount and the chemical type of the acidic media used for washing can significantly influence the content of remaining non-framework aluminum (NFA) and consequently further affect the hydrothermal stability of the washed REY products. The content of remaining non-framework aluminum can be well correlated with the crystallinity of REY products.
基金The authors gratefully acknowledge the financial support from the National Natural Science Foundation of China （Nos. 21375005, 21575054 and 21527808）.
文摘An anomalous enhancement of fluorescence of carbon dots （CDs） was observed via lanthanum （La） doping. La-doped CDs （La-CDs） were prepared through microwave pyrolysis within 4 min. With La^3＋ doping, the emission band shifted from blue to green although LaB＋ is non-fluorescent. The quantum yield and fluorescence lifetime improved by about 20% and 35%, respectively. All experiment results indicate that La^3＋ doping is an effective way to tune fluorescence and improve the performance of CDs. Another unique attribute of La-CDs is high sensitivity to Fe^3＋. The La-CD-based fluorescence probe was established and used for sensitive and selective detection of Fe^3＋ with a limit of detection of 91 nmol/L. The proposed fluorescence probe also was successfully employed to visualize intracellular Fe^3＋ in live HeLa cells through cell imaging. It was also shown that yttrium exhibited the same fluorescence enhancement effect as La. The results may provide a new route for preparing CDs with special properties.
