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Novel Lanthanide Cluster Polymers Based on Cubane-like [Ln4(OH)4]^8+ Clusters and Sulfate Anions
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作者 周良良 丁玲 +2 位作者 魏坤宇 孙燕琼 陈义平 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2016年第3期375-382,共8页
Two lanthanide-oxo-cluster polymers were synthesized by hydrothermal reaction using Ln_2O_3 as initial lanthanide materials:[Ln_4(SO_4)_4(OH)_4(H_2O)_7]·_4H_2O(Ln = Er 1,Ho 2),and characterized by PXRD,I... Two lanthanide-oxo-cluster polymers were synthesized by hydrothermal reaction using Ln_2O_3 as initial lanthanide materials:[Ln_4(SO_4)_4(OH)_4(H_2O)_7]·_4H_2O(Ln = Er 1,Ho 2),and characterized by PXRD,IR spectra,X-ray single-crystal diffraction,2D IR correlation spectra and UV-visible absorption spectra.Single-crystal X-ray analyses reveal that compounds 1 and 2 are isostructural,and they are both crystallized in the orthorhombic system Pccn space group.Compound 1 is a 3D lanthanide cluster polymer based on tetranuclear cubane-like [Er_4(μ_3-OH)_4]^8+ cations and SO_4^2- anions.The overall structure of 1 can be assigned to 6-connected pcu-type topology with the point symbol of(4^12.6^3). 展开更多
关键词 lanthanide cluster polymer crystal structure tetranuclear lanthanide-oxo-clusters sulfate anion
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Self-assembly architecture of bis(guanidiniums) receptors incorporated by sulfate anions in single crystals
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作者 陆国元 宋伟 +3 位作者 唐峰 金传明 刘芳 万小宾 《Chinese Journal of Chemistry》 SCIE CAS CSCD 2000年第6期924-927,共4页
A novel bis(guanidiniums) receptor for the catalytic cleavage of phosphosdiester was prepared and self-assembly architecture through hydrogen bonds and electrostatic interactions among the bis(guanidiniums) receptor, ... A novel bis(guanidiniums) receptor for the catalytic cleavage of phosphosdiester was prepared and self-assembly architecture through hydrogen bonds and electrostatic interactions among the bis(guanidiniums) receptor, the sulfate anion and water molecule was revealed by X-ray crystallographic analysis. 展开更多
关键词 Bis(guanidiniums) receptor sulfate anion hydrogen bond SELF-ASSEMBLY
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A New Asymmetric Synthesis of (+)-(3R, 4S, 5R, 7S)-Neoclausenamide via Intramolecular Nucleophilic Attack of Carbon Anion onto Cyclic Sulfate
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作者 Jian Qiang WANG Zhu Shou LUO Wei Sheng TIAN(Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences,354 Fenglin Lu, Shanghai 200032) 《Chinese Chemical Letters》 SCIE CAS CSCD 1997年第4期281-284,共4页
An intramolecular nucleophilic substitution of carbon anion to cyclic sulfate was first employed in asymmetric synthesis of (+)-(3R, 4S, 5R, 7S)-neoclausenamide 1 which is a novel hepatoprotective lactam isolated from... An intramolecular nucleophilic substitution of carbon anion to cyclic sulfate was first employed in asymmetric synthesis of (+)-(3R, 4S, 5R, 7S)-neoclausenamide 1 which is a novel hepatoprotective lactam isolated from the dry leaves of Chinese folk medicine Clausena lansium (Lour) Skeel. The regioselectivity of beta-attack to this cyclic sulfate, just like its epoxide counterpart was attributed to the increased reactivity of beta-position by the phenyl group. 展开更多
关键词 A New Asymmetric Synthesis of Neoclausenamide via Intramolecular Nucleophilic Attack of Carbon anion onto Cyclic sulfate
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Fluoride removal by Al,Ti,and Fe hydroxides and coexisting ion effect 被引量:8
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作者 Jianfeng Zhang Timothy E.Brutus +1 位作者 Jiemin Cheng Xiaoguang Meng 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2017年第7期190-195,共6页
Batch experiments were conducted to evaluate fluoride removal by Al,Fe,and Ti-based coagulants and adsorbents,as well as the effects of coexisting ions and formation of aluminum–fluoride complexes on fluoride removal... Batch experiments were conducted to evaluate fluoride removal by Al,Fe,and Ti-based coagulants and adsorbents,as well as the effects of coexisting ions and formation of aluminum–fluoride complexes on fluoride removal by co-precipitation with alum(Al_2(SO_4)_3·18H_2O).Aluminum sulfate was more efficient than the other coagulants for fluoride removal in the pH range between 6 and 8.Nano-crystalline TiO_2 was more effective for fluoride removal than Al and Fe hydroxides in a pH range of 3–5.Coexisting anions in water decreased the removal of fluoride in the order:phosphate(2.5 mg/L) 〉 arsenate(0.1 mg/L) 〉 bicarbonate(200 mg/L) 〉sulfate(100 mg/L) = nitrate(100 mg/L) 〉 silicate(10 mg/L) at a pH of 6.0.The effect of silicate became more significant at pH 〉 7.0.Calcium and magnesium improved the removal of fluoride.Zeta-potential measurements determined that the adsorption of fluoride shifted the PZC of Al(OH)_3 precipitates from 8.9 to 8.4,indicating the chemical adsorption of fluoride at the surface.The presence of fluoride in solution significantly increased the soluble aluminum concentration at pH 〈 6.5.A Visual MINTEQ modeling study indicated that the increased aluminum solubility was caused by the formation of AlF^(2+),AlF^(+2),and AlF_3complexes.The AlF_x complexes decreased the removal of fluoride during co-precipitation with aluminum sulfate. 展开更多
关键词 Fluoride removal Co-precipitation Aluminum sulfate anion effect
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