Allylation of bulky-substituted aromatic aldehydes with allyltrichlorosilanes were catalyzed by axial biscarboline N.N-dioxide esters with high enaiitioselectivities up to 92% e.e. for l-(4-chlorophenyl)-9-methyl-9Hpy...Allylation of bulky-substituted aromatic aldehydes with allyltrichlorosilanes were catalyzed by axial biscarboline N.N-dioxide esters with high enaiitioselectivities up to 92% e.e. for l-(4-chlorophenyl)-9-methyl-9Hpyrido[3,4-b]indole-3-carbaldehyde and 90% e.e.for 1-(3-methoxyphenyl)-9-methyl-9H-pyrido[3,4-b]indole-3-carbaldehyde, respectively.Total 22 aldehydes were tested with good yields and enantioselectivities.Catalyst 4f exhibited good catalytic enantioselectivity.展开更多
In this text,we present researches on the synthesis of polyoxo-titanium clusters(PTCs)by the use of gadolinium pivalate precursor.During the synthesis process,we discover that solvents play an important role.When acet...In this text,we present researches on the synthesis of polyoxo-titanium clusters(PTCs)by the use of gadolinium pivalate precursor.During the synthesis process,we discover that solvents play an important role.When acetonitrile was used as solvent,Ti8Gd(μ2-O)(μ3-O)5(Sal)5(OPiv)2(μ2-OiPr)3(μ-OiPr)8(PTC-82)(H2Sal=salicylic acid,HOPiv=pivalic acid)was obtained.When N,N-dimethylformamide(DMF)was used as solvent under the same reaction conditions,Ti4Gd2(μ3-O)2(Sal)4(OPiv)4(μ2-OiPr)2(μ-OiPr)4(DMF)2(PTC-83)was synthesized.The solid-state UV absorption spectra revealed that the dopant of lanthanide and the incorporation of salicylic acid ligands have successfully narrowed the bandgap of PTCs.In addition,they exhibited rapid and reproducible photo-responses.展开更多
A novel electrolyte with chloromethyl pivalate （CP） used as solvent was first reported for non-aqueous lithium-oxygen （Li-O2） batteries. Since there are no α-H atoms in the structure of CP, the CP based electroly...A novel electrolyte with chloromethyl pivalate （CP） used as solvent was first reported for non-aqueous lithium-oxygen （Li-O2） batteries. Since there are no α-H atoms in the structure of CP, the CP based electrolyte in both superoxide radical solution and real LifO2 battery environment showed good chemical stability against superoxide radicals, which was confirmed by ^1H NMR and ^13C NMR measurements. Without a catalyst in the cathode of Li-O2 batteries, the batteries showed high specific capacity and cycling stability.展开更多
Unidirectional solidification of pivalic acid （PVA）-ethanol （Eth） mixture was performed to examine whether an allowable range of primary dendrite spacing definitely exists at a given growth velocity and how the ra...Unidirectional solidification of pivalic acid （PVA）-ethanol （Eth） mixture was performed to examine whether an allowable range of primary dendrite spacing definitely exists at a given growth velocity and how the range is history-dependent. PVA-0.59 wt pct Eth was unidirectionally solidified in the range of growth velocity 0.5-64 μm/s at the temperature gradient of 2.3 K/ram. Sequential change in growth velocity was imposed to determine the upper and lower limits for the allowable range of stable spacing. An allowable range of the steady state primary spacing was observed at a given growth velocity, and the extent of the range seems to be dependent on the degree to which step-increase or step-decrease in growth velocity is accomplished. As the degree of sequential change in growth velocity increases, the history-dependence of the selection for the primary dendrite spacing tends to disappear.展开更多
文摘Allylation of bulky-substituted aromatic aldehydes with allyltrichlorosilanes were catalyzed by axial biscarboline N.N-dioxide esters with high enaiitioselectivities up to 92% e.e. for l-(4-chlorophenyl)-9-methyl-9Hpyrido[3,4-b]indole-3-carbaldehyde and 90% e.e.for 1-(3-methoxyphenyl)-9-methyl-9H-pyrido[3,4-b]indole-3-carbaldehyde, respectively.Total 22 aldehydes were tested with good yields and enantioselectivities.Catalyst 4f exhibited good catalytic enantioselectivity.
基金Supported by the National Natural Science Foundation of China (21771181,and 21673238)Youth Innovation Promotion Association CAS (2017345)Shanghai Key Laboratory of Rare Earth Functional Materials and Natural Science Foundation of Fujian Province (2017J05036)。
文摘In this text,we present researches on the synthesis of polyoxo-titanium clusters(PTCs)by the use of gadolinium pivalate precursor.During the synthesis process,we discover that solvents play an important role.When acetonitrile was used as solvent,Ti8Gd(μ2-O)(μ3-O)5(Sal)5(OPiv)2(μ2-OiPr)3(μ-OiPr)8(PTC-82)(H2Sal=salicylic acid,HOPiv=pivalic acid)was obtained.When N,N-dimethylformamide(DMF)was used as solvent under the same reaction conditions,Ti4Gd2(μ3-O)2(Sal)4(OPiv)4(μ2-OiPr)2(μ-OiPr)4(DMF)2(PTC-83)was synthesized.The solid-state UV absorption spectra revealed that the dopant of lanthanide and the incorporation of salicylic acid ligands have successfully narrowed the bandgap of PTCs.In addition,they exhibited rapid and reproducible photo-responses.
基金supported by the National Basic Research Program of China (No. 2014CB932303)National Natural ScienceFoundation of China (No. 21573145)
文摘A novel electrolyte with chloromethyl pivalate （CP） used as solvent was first reported for non-aqueous lithium-oxygen （Li-O2） batteries. Since there are no α-H atoms in the structure of CP, the CP based electrolyte in both superoxide radical solution and real LifO2 battery environment showed good chemical stability against superoxide radicals, which was confirmed by ^1H NMR and ^13C NMR measurements. Without a catalyst in the cathode of Li-O2 batteries, the batteries showed high specific capacity and cycling stability.
文摘Unidirectional solidification of pivalic acid （PVA）-ethanol （Eth） mixture was performed to examine whether an allowable range of primary dendrite spacing definitely exists at a given growth velocity and how the range is history-dependent. PVA-0.59 wt pct Eth was unidirectionally solidified in the range of growth velocity 0.5-64 μm/s at the temperature gradient of 2.3 K/ram. Sequential change in growth velocity was imposed to determine the upper and lower limits for the allowable range of stable spacing. An allowable range of the steady state primary spacing was observed at a given growth velocity, and the extent of the range seems to be dependent on the degree to which step-increase or step-decrease in growth velocity is accomplished. As the degree of sequential change in growth velocity increases, the history-dependence of the selection for the primary dendrite spacing tends to disappear.
