Glycerol is a by-product of biodiesel production and is an important readily available platform chemical.Valorization of glycerol into value-added chemicals has gained immense attention.Herein,we carried out the conve...Glycerol is a by-product of biodiesel production and is an important readily available platform chemical.Valorization of glycerol into value-added chemicals has gained immense attention.Herein,we carried out the conversion of glycerol to formic acid and glycolic acid using H2O2 as an oxidant and metal(Ⅲ)triflate-based catalytic systems.Aluminum(Ⅲ)triflate was found to be the most efficient catalyst for the selective oxidation of glycerol to formic acid.A correlation between the catalytic activity of the metal cations and their hydrolysis constants(Kh)and water exchange rate constants was observed.At 70 ℃,a formic acid yield of up to 72% could be attained within 12 h.The catalyst could be recycled at least five times with a high conversion rate,and hence can also be used for the selective oxidation of other biomass platform molecules.Reaction kinetics and 1H NMR studies showed that the oxidation of glycerol(to formic acid)involved glycerol hydrolysis pathways with glyceric acid and glycolic acid as the main intermediate products.Both the [Al(OH)x]^n+ Lewis acid species and CF3SO3H Brosted acid,which were generated by the in-situ hydrolysis of Al(OTf)3,were responsible for glycerol conversion.The easy availability,high efficiency,and good recyclability of Al(OTf)3 render it suitable for the selective oxidation of glycerol to high value-added products.展开更多
Selective separation of gallium from aluminum by ion flotation using sodium dodecyl sulfate(SDS) as an anionic surfactant and fluoride as an inorganic ligand was investigated. The experimental results were analyzed us...Selective separation of gallium from aluminum by ion flotation using sodium dodecyl sulfate(SDS) as an anionic surfactant and fluoride as an inorganic ligand was investigated. The experimental results were analyzed using the stability constants and speciation diagrams of fluoride metal complexes. The presence of fluoride in the solution has a positive influence upon the separation of gallium from aluminum. The results show that increasing the fluoride concentration makes a more effective separation of gallium from aluminum because of a simultaneous increase in the complexion of aluminum with fluoride and a change in the electrical charge of the aluminum(ALF_4^-). The dehydration model of LIU and DOYLE was also applied to compare the ion flotation and the selectivity coefficients of gallium over aluminum with experimental results.展开更多
The selectivity of organosamarium(Ⅲ) hydride in reducing unsaturated carbonyl compounds has been studied. Dimeric organosamarium hydride[(C_9H_7)_2SmH]_2·4THF·NaCl prepared by the reaction of (C_9H_7)_2SmCl...The selectivity of organosamarium(Ⅲ) hydride in reducing unsaturated carbonyl compounds has been studied. Dimeric organosamarium hydride[(C_9H_7)_2SmH]_2·4THF·NaCl prepared by the reaction of (C_9H_7)_2SmCl·2THF with NaH in THF reacts with unsaturated carbonyl compounds to give the corresponding reduction products with a high selectivity. The carbonyl groups have been reduced while the carbon-carbon double bonds are not affected.展开更多
A derivative of thiazole（AAT） has been explored as a sensing material for preparation a selective Lu（III） PVC-based membrane sensor.The proposed sensor exhibits a Nernstian response over a wide concentration range...A derivative of thiazole（AAT） has been explored as a sensing material for preparation a selective Lu（III） PVC-based membrane sensor.The proposed sensor exhibits a Nernstian response over a wide concentration range from 1.0×10^（-6） to 1.0×10^（-1） mol/L of Lu（Ⅲ） and the detection limit is 5.7×10^（-7） mol/L.The sensor response is independent of pH of the solution in the range 3.2-8.8 and possesses the advantages of fast response time（～6） and in particular,good selectivity to the lutetium ions with regard to most common metal ions,and especially all lanthanide ions.展开更多
Diethylenetriaminepentaacetic dianhydride was co-polymerized with dodecyl ester and benzyl ester of lysine,and octodecyl ester and benzyl ester of lysine respectively to give two terpolymers. These two terpolymer liga...Diethylenetriaminepentaacetic dianhydride was co-polymerized with dodecyl ester and benzyl ester of lysine,and octodecyl ester and benzyl ester of lysine respectively to give two terpolymers. These two terpolymer ligands were reacted with GdCl 3 to afford amphiphilic oligomers of Gd(Ⅲ) complexes. These new ligands and Gd(Ⅲ) complexes were characterized by IR, 1H NMR and elemental analysis. The oligomeric complexes show a higher relaxivity as compared to that of Gd(DTPA) which is widely used in clinic diagnoses. The Gd(Ⅲ) complex derived from octodecyl ester demonstrated liver-selective enhancement for MR imaging of Wistar rat. The ratios of signal to noise ( S/N ) in the proton intensity imaging were enhanced,respectively,by 15%,27%,and 36% at the time of 5,30 and 45 min after injection of this complex.展开更多
基金the National Natural Science Foundation of China(21773061,21373082)the Innovation Program of Shanghai Municipal Education Commission(15ZZ031)~~
文摘Glycerol is a by-product of biodiesel production and is an important readily available platform chemical.Valorization of glycerol into value-added chemicals has gained immense attention.Herein,we carried out the conversion of glycerol to formic acid and glycolic acid using H2O2 as an oxidant and metal(Ⅲ)triflate-based catalytic systems.Aluminum(Ⅲ)triflate was found to be the most efficient catalyst for the selective oxidation of glycerol to formic acid.A correlation between the catalytic activity of the metal cations and their hydrolysis constants(Kh)and water exchange rate constants was observed.At 70 ℃,a formic acid yield of up to 72% could be attained within 12 h.The catalyst could be recycled at least five times with a high conversion rate,and hence can also be used for the selective oxidation of other biomass platform molecules.Reaction kinetics and 1H NMR studies showed that the oxidation of glycerol(to formic acid)involved glycerol hydrolysis pathways with glyceric acid and glycolic acid as the main intermediate products.Both the [Al(OH)x]^n+ Lewis acid species and CF3SO3H Brosted acid,which were generated by the in-situ hydrolysis of Al(OTf)3,were responsible for glycerol conversion.The easy availability,high efficiency,and good recyclability of Al(OTf)3 render it suitable for the selective oxidation of glycerol to high value-added products.
基金the Iran National Elites FoundationIranian Mines&Mining Industries Development&the Renovation and Geological Survey of Iran for financial support
文摘Selective separation of gallium from aluminum by ion flotation using sodium dodecyl sulfate(SDS) as an anionic surfactant and fluoride as an inorganic ligand was investigated. The experimental results were analyzed using the stability constants and speciation diagrams of fluoride metal complexes. The presence of fluoride in the solution has a positive influence upon the separation of gallium from aluminum. The results show that increasing the fluoride concentration makes a more effective separation of gallium from aluminum because of a simultaneous increase in the complexion of aluminum with fluoride and a change in the electrical charge of the aluminum(ALF_4^-). The dehydration model of LIU and DOYLE was also applied to compare the ion flotation and the selectivity coefficients of gallium over aluminum with experimental results.
文摘The selectivity of organosamarium(Ⅲ) hydride in reducing unsaturated carbonyl compounds has been studied. Dimeric organosamarium hydride[(C_9H_7)_2SmH]_2·4THF·NaCl prepared by the reaction of (C_9H_7)_2SmCl·2THF with NaH in THF reacts with unsaturated carbonyl compounds to give the corresponding reduction products with a high selectivity. The carbonyl groups have been reduced while the carbon-carbon double bonds are not affected.
基金NFCRS,Nuclear Science&Technology Research Institute(Tehran,Iran)for their financial support
文摘A derivative of thiazole（AAT） has been explored as a sensing material for preparation a selective Lu（III） PVC-based membrane sensor.The proposed sensor exhibits a Nernstian response over a wide concentration range from 1.0×10^（-6） to 1.0×10^（-1） mol/L of Lu（Ⅲ） and the detection limit is 5.7×10^（-7） mol/L.The sensor response is independent of pH of the solution in the range 3.2-8.8 and possesses the advantages of fast response time（～6） and in particular,good selectivity to the lutetium ions with regard to most common metal ions,and especially all lanthanide ions.
文摘Diethylenetriaminepentaacetic dianhydride was co-polymerized with dodecyl ester and benzyl ester of lysine,and octodecyl ester and benzyl ester of lysine respectively to give two terpolymers. These two terpolymer ligands were reacted with GdCl 3 to afford amphiphilic oligomers of Gd(Ⅲ) complexes. These new ligands and Gd(Ⅲ) complexes were characterized by IR, 1H NMR and elemental analysis. The oligomeric complexes show a higher relaxivity as compared to that of Gd(DTPA) which is widely used in clinic diagnoses. The Gd(Ⅲ) complex derived from octodecyl ester demonstrated liver-selective enhancement for MR imaging of Wistar rat. The ratios of signal to noise ( S/N ) in the proton intensity imaging were enhanced,respectively,by 15%,27%,and 36% at the time of 5,30 and 45 min after injection of this complex.
