Although literature abounds with examples of formation of perhaloalkanes by photo-lytic or Lewis-acid induced halogen exchange reactions involving radical or carbocationintermediates,the procedures are seldom applicab...Although literature abounds with examples of formation of perhaloalkanes by photo-lytic or Lewis-acid induced halogen exchange reactions involving radical or carbocationintermediates,the procedures are seldom applicable to the preparation of perhaloalkanes ingood yields under mild conditions.Recently,we have reported the spontaneous reactionsof some perhalofluoroalkanes with various types of nucleophiles.All these reactions areinitiated by the halophilic attack of nucleophiles on C—Br or C—Cl bonds,followed byanionic chain steps involving carbanion as well as olefin intermediates.Notably,the latter areformed after the β-elimination of a good leaving group from the former.On the other hand,it is well known that halogenated carbanions can effectively make halophilic attacks on theC—X bonds of other halogenated substrates,e.g.,in the“halogen dance”of Bunnett.There-展开更多
a-Oxo ketene dithioacetals 2 via 1,2-nucleophilie addition by methallyl magnesius chloride afforded corresponding alcohols (3). Treated with water or methanol and catalyzed by Lewis acid, the alcohols 3 were converted...a-Oxo ketene dithioacetals 2 via 1,2-nucleophilie addition by methallyl magnesius chloride afforded corresponding alcohols (3). Treated with water or methanol and catalyzed by Lewis acid, the alcohols 3 were converted regiospecifical ly to substituted phenols 5' or related phenol methyl ethers 5 respectively. This reaction is a novel approach to the synthesis of phenols and their derivatives starting from non-aromatic precursors.展开更多
Seven new boronic acid adducts of technetium(III) tris(dioxime) (BATO) were prepared and the biodistribution in mice of Tc-99m labelled BATOs were determined. The uptake of 1.62%1D in mice heart at 2 min after injecti...Seven new boronic acid adducts of technetium(III) tris(dioxime) (BATO) were prepared and the biodistribution in mice of Tc-99m labelled BATOs were determined. The uptake of 1.62%1D in mice heart at 2 min after injection of (TcCl)-Tc-99m(MeCDO)(3)BMe indicates high myocardial extraction of this BATO. (TcCl)-Tc-99m(MeCDO)(3)BMe shows promise as a myocardial perfusion imaging agent.展开更多
1 Introduction In the present paper,MgCl2·6H2O,FeCl3·6H2O,and CeCl3·6H2O were used as raw materials in the precipitationhydrothermal method to synthesize MgF eC e hydrotalcite.The effects of the Fe:Ce m...1 Introduction In the present paper,MgCl2·6H2O,FeCl3·6H2O,and CeCl3·6H2O were used as raw materials in the precipitationhydrothermal method to synthesize MgF eC e hydrotalcite.The effects of the Fe:Ce molar ratio on the composition,crystal structure,and thermal stability of hydrotalcite are examined.Energy-dispersive X-ray spectroscopy(EDS),X-展开更多
A new blend of poly(2-hydroxyethyl methacrylate) (PHEMA) with poly (ethylene glycol) (PEG) was prepared. The results from solid-state NMR indicate that the PHEMA/PEG(88:12, w/w) blend is miscible on a molecular level.
Nitrogen oxides(NO_2 and NO)are absorbed by tributyl phosphorate(TBP)to fom a new complex mixture of TBP-NO_x. which is used as a selective oddizing agent to oxidize benzylalcohols to corresponding sldehydes or ketone...Nitrogen oxides(NO_2 and NO)are absorbed by tributyl phosphorate(TBP)to fom a new complex mixture of TBP-NO_x. which is used as a selective oddizing agent to oxidize benzylalcohols to corresponding sldehydes or ketones In high yield. In the reaction process, nitrogen oxides are llberated mildly and mainly reduced to nitrogen, while tributyl phosphorate is recovered end recycled.展开更多
FeTi_1-O_2（= 0.00,0.05,0.10） nanocomposites are synthesized using a sol-gel method involving an ethanol solvent in the presence of ethylene glycol as the stabilizer,and acetic acid as the chemical reagent.Their stru...FeTi_1-O_2（= 0.00,0.05,0.10） nanocomposites are synthesized using a sol-gel method involving an ethanol solvent in the presence of ethylene glycol as the stabilizer,and acetic acid as the chemical reagent.Their structural and optical analyses are studied to reveal their physicochemical properties.Using the x-ray diffractometer（XRD）analysis,the size of the nanoparticles（NPs） is found to be 18-32 nm,where the size of the NPs decreases down to 18 nm when Fe impurity of up to 10% is added,whereas their structure remains unchanged.The results also indicate that the structure of the NPs is tetragonal in the anatase phase.The Fourier transform infrared spectroscopy analysis suggests the presence of a vibration bond（Ti-O） in the sample.The photoluminescence analysis indicates that the diffusion of Fe^（3＋） ions into the TiO_2 matrix results in a decreasing electron-hole recombination,and increases the photocatalytic properties,where the best efficiency appears at an impurity of10%.The UV-diffuse reflection spectroscopy analysis indicates that with the elevation of iron impurity,the band gap value decreases from 3.47 eV for the pure sample to 2.95 eV for the 10 mol% Fe-doped TiO_2 NPs.展开更多
Energy is the key to our future.Whether to the production,storage or use of energy,carbon materials could provide a good solution.They are closely related to people’s daily life and regarded as one of the most promis...Energy is the key to our future.Whether to the production,storage or use of energy,carbon materials could provide a good solution.They are closely related to people’s daily life and regarded as one of the most promising candidates for the flexible electrodes in energy storage devices.Recently,a research team from the Qingdao Institute of Bioenergy and Bioprocess Technology,Chinese Academy of Sciences prepared a展开更多
Type of Company： Government institution. New Preparartions and Late-Model Drug Delivery System Technical Plaform of Peking University School of Pharmaceutical Sciences is a national technical plaform for developing n...Type of Company： Government institution. New Preparartions and Late-Model Drug Delivery System Technical Plaform of Peking University School of Pharmaceutical Sciences is a national technical plaform for developing new and important drugs. The person in charge for the platform is a pharmaceutical science professor of Peking University School of Pharmaceutical Sciences. The plaform selects the following as the main research areas： late-model carrier drug delivery system, biotechnological drug delivery system, mucous and transdermal drug delivery system, oral controlled-release drug delivery system, and four corresponding research teams are set up to study in depth the main problems and key issues.展开更多
Type of Company： Government institution. New Preparartions and Late-Model Drug Delivery System Technical Plaform of Peking University School of Pharmaceutical Sciences is a national technical plaform for developing n...Type of Company： Government institution. New Preparartions and Late-Model Drug Delivery System Technical Plaform of Peking University School of Pharmaceutical Sciences is a national technical plaform for developing new and important drugs. The person in charge for the platform is a pharmaceutical science professor of Peking University School of Pharmaceutical Sciences. The plaform selects the following as the main research areas： late-model carrier drug delivery system, biotechnological drug delivery system,展开更多
Perfluoroalkyl chloride can be converted into hydroperfluoroalkane with zinc powder in the presence of nickel dichloride.A single electron transfer mechanism is proposed.
Fifteen pyridine and substituted benzene diselenides,seleninic acids and seleninic anhydrides have been synthesized.Among them,4,4'-dipyridinediselenide,bis(2,4-dimethoxyphenyl)diselenide, 2,4-dimethoxyphenyl sele...Fifteen pyridine and substituted benzene diselenides,seleninic acids and seleninic anhydrides have been synthesized.Among them,4,4'-dipyridinediselenide,bis(2,4-dimethoxyphenyl)diselenide, 2,4-dimethoxyphenyl seleninic acid,2-pyridineseleninic acid,2-pyridineseleninic anhydride,4-pyridine- seleninic anhydride,2-nitrophenyl seleninic anhydride and 4-nitrophenyl seleninic anhydride were new compounds.Their regioselective oxidation or dehydrogenation of β-pinene,3β-benzoyloxycholest- 5-ene and androstan-3-one have been studied and compared.2-Pyridineseleninic anhydride is a more efficient oxidant than the others;most of the substituted benzeneseleno derivatives did not give the expected products.展开更多
With the support by the National Natural Science Foundation of China and the Ministry of Science and Technology of China,the research team led by Prof.Ding Guqiao(丁古巧)and Dr.He Peng(何朋)at Shanghai Institute of Mi...With the support by the National Natural Science Foundation of China and the Ministry of Science and Technology of China,the research team led by Prof.Ding Guqiao(丁古巧)and Dr.He Peng(何朋)at Shanghai Institute of Microsystem and Information Technology,Chinese Academy of Sciences,achieved展开更多
The synthesis and the structural characterization of the title compound HNa[WO（CCH）-（OCCH）（HO）][HWO]·13.5 HO are described.It is known that the mixed oxo-ethylidyne-capped tritungsten cluster can be obtaine...The synthesis and the structural characterization of the title compound HNa[WO（CCH）-（OCCH）（HO）][HWO]·13.5 HO are described.It is known that the mixed oxo-ethylidyne-capped tritungsten cluster can be obtained by Zn dust reduction of NaWO·2HO in acetic anhydride.The title compound has been characterized by X-ray diffraction,UV/VIS andH NMR spectra.The tungsten atoms in the cluster cation and anion are in the oxidation states of W（IV）and W（VI）respectively.The crystal is rhombohedral with the space group R32,a=17.058（3）,c=49.665（9）,γ=120°,V=12516（9）,Z=6,final R=0.037 for 2071 reflections with I≥3σ（I）.Boththe cluster cation and anion have a Csymmetry.The important interatomic distances in angstroms forthe cluster cation are:W—W,2.730（2）;W—μ-O,2.00;W—O（carboxyl）,2.12;W—O,2.18（2）.展开更多
基金the National Natural Science Foundation of China.
文摘Although literature abounds with examples of formation of perhaloalkanes by photo-lytic or Lewis-acid induced halogen exchange reactions involving radical or carbocationintermediates,the procedures are seldom applicable to the preparation of perhaloalkanes ingood yields under mild conditions.Recently,we have reported the spontaneous reactionsof some perhalofluoroalkanes with various types of nucleophiles.All these reactions areinitiated by the halophilic attack of nucleophiles on C—Br or C—Cl bonds,followed byanionic chain steps involving carbanion as well as olefin intermediates.Notably,the latter areformed after the β-elimination of a good leaving group from the former.On the other hand,it is well known that halogenated carbanions can effectively make halophilic attacks on theC—X bonds of other halogenated substrates,e.g.,in the“halogen dance”of Bunnett.There-
文摘a-Oxo ketene dithioacetals 2 via 1,2-nucleophilie addition by methallyl magnesius chloride afforded corresponding alcohols (3). Treated with water or methanol and catalyzed by Lewis acid, the alcohols 3 were converted regiospecifical ly to substituted phenols 5' or related phenol methyl ethers 5 respectively. This reaction is a novel approach to the synthesis of phenols and their derivatives starting from non-aromatic precursors.
文摘Seven new boronic acid adducts of technetium(III) tris(dioxime) (BATO) were prepared and the biodistribution in mice of Tc-99m labelled BATOs were determined. The uptake of 1.62%1D in mice heart at 2 min after injection of (TcCl)-Tc-99m(MeCDO)(3)BMe indicates high myocardial extraction of this BATO. (TcCl)-Tc-99m(MeCDO)(3)BMe shows promise as a myocardial perfusion imaging agent.
基金supported by China Postdoctoral Science Foundation(No.118918)West Light Foundation of the Chinese Academy of Science
文摘1 Introduction In the present paper,MgCl2·6H2O,FeCl3·6H2O,and CeCl3·6H2O were used as raw materials in the precipitationhydrothermal method to synthesize MgF eC e hydrotalcite.The effects of the Fe:Ce molar ratio on the composition,crystal structure,and thermal stability of hydrotalcite are examined.Energy-dispersive X-ray spectroscopy(EDS),X-
文摘A new blend of poly(2-hydroxyethyl methacrylate) (PHEMA) with poly (ethylene glycol) (PEG) was prepared. The results from solid-state NMR indicate that the PHEMA/PEG(88:12, w/w) blend is miscible on a molecular level.
文摘Nitrogen oxides(NO_2 and NO)are absorbed by tributyl phosphorate(TBP)to fom a new complex mixture of TBP-NO_x. which is used as a selective oddizing agent to oxidize benzylalcohols to corresponding sldehydes or ketones In high yield. In the reaction process, nitrogen oxides are llberated mildly and mainly reduced to nitrogen, while tributyl phosphorate is recovered end recycled.
文摘FeTi_1-O_2（= 0.00,0.05,0.10） nanocomposites are synthesized using a sol-gel method involving an ethanol solvent in the presence of ethylene glycol as the stabilizer,and acetic acid as the chemical reagent.Their structural and optical analyses are studied to reveal their physicochemical properties.Using the x-ray diffractometer（XRD）analysis,the size of the nanoparticles（NPs） is found to be 18-32 nm,where the size of the NPs decreases down to 18 nm when Fe impurity of up to 10% is added,whereas their structure remains unchanged.The results also indicate that the structure of the NPs is tetragonal in the anatase phase.The Fourier transform infrared spectroscopy analysis suggests the presence of a vibration bond（Ti-O） in the sample.The photoluminescence analysis indicates that the diffusion of Fe^（3＋） ions into the TiO_2 matrix results in a decreasing electron-hole recombination,and increases the photocatalytic properties,where the best efficiency appears at an impurity of10%.The UV-diffuse reflection spectroscopy analysis indicates that with the elevation of iron impurity,the band gap value decreases from 3.47 eV for the pure sample to 2.95 eV for the 10 mol% Fe-doped TiO_2 NPs.
基金supported by the Chinese Academy of Sciencesthe Natural Science Foundation of Shandong Provincethe National Natural Science Foundation of China
文摘Energy is the key to our future.Whether to the production,storage or use of energy,carbon materials could provide a good solution.They are closely related to people’s daily life and regarded as one of the most promising candidates for the flexible electrodes in energy storage devices.Recently,a research team from the Qingdao Institute of Bioenergy and Bioprocess Technology,Chinese Academy of Sciences prepared a
文摘Type of Company： Government institution. New Preparartions and Late-Model Drug Delivery System Technical Plaform of Peking University School of Pharmaceutical Sciences is a national technical plaform for developing new and important drugs. The person in charge for the platform is a pharmaceutical science professor of Peking University School of Pharmaceutical Sciences. The plaform selects the following as the main research areas： late-model carrier drug delivery system, biotechnological drug delivery system, mucous and transdermal drug delivery system, oral controlled-release drug delivery system, and four corresponding research teams are set up to study in depth the main problems and key issues.
文摘Type of Company： Government institution. New Preparartions and Late-Model Drug Delivery System Technical Plaform of Peking University School of Pharmaceutical Sciences is a national technical plaform for developing new and important drugs. The person in charge for the platform is a pharmaceutical science professor of Peking University School of Pharmaceutical Sciences. The plaform selects the following as the main research areas： late-model carrier drug delivery system, biotechnological drug delivery system,
基金This work was supported by the National Natural Science Foundation of China.
文摘Perfluoroalkyl chloride can be converted into hydroperfluoroalkane with zinc powder in the presence of nickel dichloride.A single electron transfer mechanism is proposed.
文摘Fifteen pyridine and substituted benzene diselenides,seleninic acids and seleninic anhydrides have been synthesized.Among them,4,4'-dipyridinediselenide,bis(2,4-dimethoxyphenyl)diselenide, 2,4-dimethoxyphenyl seleninic acid,2-pyridineseleninic acid,2-pyridineseleninic anhydride,4-pyridine- seleninic anhydride,2-nitrophenyl seleninic anhydride and 4-nitrophenyl seleninic anhydride were new compounds.Their regioselective oxidation or dehydrogenation of β-pinene,3β-benzoyloxycholest- 5-ene and androstan-3-one have been studied and compared.2-Pyridineseleninic anhydride is a more efficient oxidant than the others;most of the substituted benzeneseleno derivatives did not give the expected products.
文摘With the support by the National Natural Science Foundation of China and the Ministry of Science and Technology of China,the research team led by Prof.Ding Guqiao(丁古巧)and Dr.He Peng(何朋)at Shanghai Institute of Microsystem and Information Technology,Chinese Academy of Sciences,achieved
基金the National Natural Science Foundation of China.
文摘The synthesis and the structural characterization of the title compound HNa[WO（CCH）-（OCCH）（HO）][HWO]·13.5 HO are described.It is known that the mixed oxo-ethylidyne-capped tritungsten cluster can be obtained by Zn dust reduction of NaWO·2HO in acetic anhydride.The title compound has been characterized by X-ray diffraction,UV/VIS andH NMR spectra.The tungsten atoms in the cluster cation and anion are in the oxidation states of W（IV）and W（VI）respectively.The crystal is rhombohedral with the space group R32,a=17.058（3）,c=49.665（9）,γ=120°,V=12516（9）,Z=6,final R=0.037 for 2071 reflections with I≥3σ（I）.Boththe cluster cation and anion have a Csymmetry.The important interatomic distances in angstroms forthe cluster cation are:W—W,2.730（2）;W—μ-O,2.00;W—O（carboxyl）,2.12;W—O,2.18（2）.
