All-inorganic cesium lead halide perovskite quantum dots (QDs) have been a promising candidate for optoelectronic devices in recent years,such as light-emitting diodes,photodetectors and solar cells,owing to their sup...All-inorganic cesium lead halide perovskite quantum dots (QDs) have been a promising candidate for optoelectronic devices in recent years,such as light-emitting diodes,photodetectors and solar cells,owing to their superb optoelectronic properties.Still,the stability issue of nanocrystals is a bottleneck for their practical application.Herein,we report a facile method for the synthesis of a series of phosphine ligand modified CsPbBr3 QDs with high PL intensity.By introducing organic phosphine ligands,the tolerance of CsPbBr3 QDs to ethanol,water and UV light was dramatically improved.Moreover,the phosphine ligand modified QD films deposited on the glass subtracts exhibit superior PL intensity and optical stability to those of pristine QD based films.展开更多
To address the issue of hemilabile catalyst in olefin polymerization catalysis, a cyclizing strategy was used to construct novel N-bridged phosphine-carbonyl palladium and nickel catalysts, resulting in improvements o...To address the issue of hemilabile catalyst in olefin polymerization catalysis, a cyclizing strategy was used to construct novel N-bridged phosphine-carbonyl palladium and nickel catalysts, resulting in improvements on ethylene(co)polymerizations. The N-bridged phosphinecarbonyl Pd catalysts(Pd1-Pd5) and Ni catalysts(Ni1-Ni5) bearing five-to eight-membered-ring structures were designed and synthesized.Catalytic performance for ethylene(co)polymerization became better as the size of N-containing bridge increased. The seven-membered-ring bridged catalysts Pd4 and Ni4 exhibited the best performance in terms of catalytic activity, polymer molecular weight and incorporation of acrylates and acrylic acid. The better performance of these catalysts bearing larger-size bridges was tentatively attributed to the methyleneinduced higher electron density around nitrogen, which strenghtens the coordination of carbonyl group to metal center, and also to the steric effect offered by this cyclization. This work provides a new strategy to enhance hemilabile polymerization catalysts.展开更多
The highly water-soluble phosphine ligands Na2O3PCH2CH2NH(CH2CH2O)nCH2CH2N- (CH2PPh2)2 (n=1,2,3) were prepared by a new and simple route under mild conditions in good yield; the palladium (II) complexes of the ligands...The highly water-soluble phosphine ligands Na2O3PCH2CH2NH(CH2CH2O)nCH2CH2N- (CH2PPh2)2 (n=1,2,3) were prepared by a new and simple route under mild conditions in good yield; the palladium (II) complexes of the ligands 3a~c with 2:1 or 4:1 -PPh2 to Pd2+ molar ratio were also prepared and characterized .展开更多
The use of intramolecular reactions involving palladium/imidazolium salts to synthesize hetero-cyclic compounds is described. Reactivity of phenyl, ethyl and methyl substituents leading to isolation of various isomeri...The use of intramolecular reactions involving palladium/imidazolium salts to synthesize hetero-cyclic compounds is described. Reactivity of phenyl, ethyl and methyl substituents leading to isolation of various isomeric products is also illustrated. Rearrangement of phenyl intermediates to furnish benzoxazoles is also mentioned.展开更多
Over the past two decades,homogeneous gold catalysis has experienced exponential development and contributed a plethora of highly valuable synthetic methods to the synthetic toolbox.Metal–ligand cooperative catalysis...Over the past two decades,homogeneous gold catalysis has experienced exponential development and contributed a plethora of highly valuable synthetic methods to the synthetic toolbox.Metal–ligand cooperative catalysis is a versatile strategy for achieving highly efficient and/or novel catalysis but has seldom been explored in gold chemistry.This minireview summarizes the progress we have made in developing remotely functionalized biaryl-2-ylphosphine ligands and employing them in cooperative gold catalysis that achieves excellent catalytic efficiency or realizes previously unknown reactivities.This approach also provides new venues for implementing asymmetric gold catalysis.展开更多
Tropos phosphine-oxazoline ligands have shown interesting coordination behavior and excellent chiral inducing ability in asymmetry catalysis.Here we present a convenient and economic route for the synthesis of this ty...Tropos phosphine-oxazoline ligands have shown interesting coordination behavior and excellent chiral inducing ability in asymmetry catalysis.Here we present a convenient and economic route for the synthesis of this type of ligands.According to this new route,the ligands with different electronic and steric properties have been prepared successfully.展开更多
基金National Natural Science Foundation of China (No. 21771063)State Key Research Development Program of China (No. 2016YFA0204200)Fundamental Research Funds for the Central Universities in China (Nos. WJ1714046 and 222201717003).
文摘All-inorganic cesium lead halide perovskite quantum dots (QDs) have been a promising candidate for optoelectronic devices in recent years,such as light-emitting diodes,photodetectors and solar cells,owing to their superb optoelectronic properties.Still,the stability issue of nanocrystals is a bottleneck for their practical application.Herein,we report a facile method for the synthesis of a series of phosphine ligand modified CsPbBr3 QDs with high PL intensity.By introducing organic phosphine ligands,the tolerance of CsPbBr3 QDs to ethanol,water and UV light was dramatically improved.Moreover,the phosphine ligand modified QD films deposited on the glass subtracts exhibit superior PL intensity and optical stability to those of pristine QD based films.
基金financial support from the National Natural Science Foundation of China (Nos. 22122110 ad 21871250)the Jilin Provincial Science and Technology Department Program (No. 20200801009GH)Shaanxi Provincial Natural Science Basic Research Program-Shaanxi Coal and Chemical Industry Group Co., Ltd. Joint Fund (No. 2019JLZ-02)。
文摘To address the issue of hemilabile catalyst in olefin polymerization catalysis, a cyclizing strategy was used to construct novel N-bridged phosphine-carbonyl palladium and nickel catalysts, resulting in improvements on ethylene(co)polymerizations. The N-bridged phosphinecarbonyl Pd catalysts(Pd1-Pd5) and Ni catalysts(Ni1-Ni5) bearing five-to eight-membered-ring structures were designed and synthesized.Catalytic performance for ethylene(co)polymerization became better as the size of N-containing bridge increased. The seven-membered-ring bridged catalysts Pd4 and Ni4 exhibited the best performance in terms of catalytic activity, polymer molecular weight and incorporation of acrylates and acrylic acid. The better performance of these catalysts bearing larger-size bridges was tentatively attributed to the methyleneinduced higher electron density around nitrogen, which strenghtens the coordination of carbonyl group to metal center, and also to the steric effect offered by this cyclization. This work provides a new strategy to enhance hemilabile polymerization catalysts.
文摘The highly water-soluble phosphine ligands Na2O3PCH2CH2NH(CH2CH2O)nCH2CH2N- (CH2PPh2)2 (n=1,2,3) were prepared by a new and simple route under mild conditions in good yield; the palladium (II) complexes of the ligands 3a~c with 2:1 or 4:1 -PPh2 to Pd2+ molar ratio were also prepared and characterized .
文摘The use of intramolecular reactions involving palladium/imidazolium salts to synthesize hetero-cyclic compounds is described. Reactivity of phenyl, ethyl and methyl substituents leading to isolation of various isomeric products is also illustrated. Rearrangement of phenyl intermediates to furnish benzoxazoles is also mentioned.
基金supported by the National Science Foundation,Division of Chemistry(NSF CHE 1800525).
文摘Over the past two decades,homogeneous gold catalysis has experienced exponential development and contributed a plethora of highly valuable synthetic methods to the synthetic toolbox.Metal–ligand cooperative catalysis is a versatile strategy for achieving highly efficient and/or novel catalysis but has seldom been explored in gold chemistry.This minireview summarizes the progress we have made in developing remotely functionalized biaryl-2-ylphosphine ligands and employing them in cooperative gold catalysis that achieves excellent catalytic efficiency or realizes previously unknown reactivities.This approach also provides new venues for implementing asymmetric gold catalysis.
基金supported by the National Natural Science Foundation of China (20772081)Science and Technology Commission of Shanghai Municipality (09431902500)
文摘Tropos phosphine-oxazoline ligands have shown interesting coordination behavior and excellent chiral inducing ability in asymmetry catalysis.Here we present a convenient and economic route for the synthesis of this type of ligands.According to this new route,the ligands with different electronic and steric properties have been prepared successfully.
