A series of clip-shaped cationic molecular corners C1~C4(C1=[(bpy)_(2)Pd_(2)(L^(1))_(2)]^(2+),C2=[(dmbpy)_(2)Pd_(2)(L^(1))_(2)]^(2+),C3=(bpy)_(2)Pd_(2)(L^(2))_(2)]^(2+),C4=(dmbpy)_(2)Pd_(2)(L^(2))_(2)]^(2+),bpy=2,2-bi...A series of clip-shaped cationic molecular corners C1~C4(C1=[(bpy)_(2)Pd_(2)(L^(1))_(2)]^(2+),C2=[(dmbpy)_(2)Pd_(2)(L^(1))_(2)]^(2+),C3=(bpy)_(2)Pd_(2)(L^(2))_(2)]^(2+),C4=(dmbpy)_(2)Pd_(2)(L^(2))_(2)]^(2+),bpy=2,2-bipyridine,dmbpy=4,4΄-dimethyl-2,2-bipyridine)were synthesized through dipalladium complexes[(bpy)_(2)Pd_(2)(NO_(3))_(2)](NO_(3))_(2),[(dmbpy)_(2)Pd_(2)(NO_(3))_(2)](NO_(3))_(2)and bifunctional pyrazole ligands 4-(3,4-dimethoxyphenyl)-3,5-dimethyl-1H-pyrazol(HL^(1))and 4,4΄-(5-(^(1)H-pyrazol-4-yl)-1,3-phenylene)dipyridine(HL^(2)).Complexes C1~C4 were characterized by^(1)H and^(13)C NMR,electrospray ionization mass spectrometry(ESI-MS),elemental analysis,and IR spectroscopy.The X-ray diffraction analysis of C1∙2NO_(3)−revealed a Pd_(2)dimetallic clip-shaped structure which was synthesized by two bifunctional ligands doubly bridged by the[(bpy)Pd]_(2)dimetal units.Additionally,all of the complexes with NO_(3)−as counter anions exhibited high-efficiency catalytical performance in the Suzuki-coupling reaction attributed to the tunable impact and weak dinuclear Pd(Ⅱ)···Pd(Ⅱ)intramolecular bonding interaction.展开更多
This work reported a convenient method for the preparation of enantiomerically pure 6-aryl-2,2＇-dihydroxy-1, l＇- binaphthyl derivatives starting from the commercially available （R）-2,2＇-hydroxy-l, l＇-binaphthyl ...This work reported a convenient method for the preparation of enantiomerically pure 6-aryl-2,2＇-dihydroxy-1, l＇- binaphthyl derivatives starting from the commercially available （R）-2,2＇-hydroxy-l, l＇-binaphthyl [（R）-I] via bromi- nation, hydrolysis and Suzuki cross coupling reaction. This novel synthetie method was characterized with high re- gioselectivity, simple operation, mild reaction conditions, and excellent yield （up to 73%）. On the other hand, we synthesized the target unknown compounds, which were confirmed by IR, 1H NMR, 13C NMR, MS and elementary analysis.展开更多
This paper describes the synthesis and free radical polymerization of 2,5 bis(4′ alkyloxyphenyl)styrene(M n ) for mesogen jacketed liquid crystal polymers(MJLCPs), where p terphenyl subsituted by alkoxy groups at bot...This paper describes the synthesis and free radical polymerization of 2,5 bis(4′ alkyloxyphenyl)styrene(M n ) for mesogen jacketed liquid crystal polymers(MJLCPs), where p terphenyl subsituted by alkoxy groups at both ends was used as mesogenic unit. Because of the absence of the polar linkage groups, such as —COO— or —CONH— as employed in the previous reported MJLCPs, M n is believed to be polymerized easily by both free radical polymerization and ionic polymerization. The chemical structure of M n was proved by 1H NMR, mass spectrometry and elementary analysis. Their phase transition and liquid crystallinity were characterized by DSC and POM. Although M 1, M 2, M 3 and M 4 exhibited monotropic nematic mesophase, M 5 displayed enantiotropic nematic mesophase presumably because of its decreased melting transition temperature. All monomers were easily polymerized to moderately high molecular weight polymers. At elevated temperature above T g, poly[2,5 bis(4′ alkoxyphenyl)styrene] showed a very stable mesophase. The formed birefrigence did not disappear until thermal decomposition started. Compared to other MJLCPs, the polymers reported here have much higher thermal stability. [WT5HZ]展开更多
基金the Beijing Natural Science Foundation of China(2212002)National Natural Science Foundation of China(21906002,21471011)+2 种基金the Beijing Municipal Science and Technology Project(KM202010005010)the Beijing Municipal High Level Innovative Team Building Program(IDHT20180504)the Beijing Outstanding Young Scientist Program(BJJWZYJH01201910005017)。
文摘A series of clip-shaped cationic molecular corners C1~C4(C1=[(bpy)_(2)Pd_(2)(L^(1))_(2)]^(2+),C2=[(dmbpy)_(2)Pd_(2)(L^(1))_(2)]^(2+),C3=(bpy)_(2)Pd_(2)(L^(2))_(2)]^(2+),C4=(dmbpy)_(2)Pd_(2)(L^(2))_(2)]^(2+),bpy=2,2-bipyridine,dmbpy=4,4΄-dimethyl-2,2-bipyridine)were synthesized through dipalladium complexes[(bpy)_(2)Pd_(2)(NO_(3))_(2)](NO_(3))_(2),[(dmbpy)_(2)Pd_(2)(NO_(3))_(2)](NO_(3))_(2)and bifunctional pyrazole ligands 4-(3,4-dimethoxyphenyl)-3,5-dimethyl-1H-pyrazol(HL^(1))and 4,4΄-(5-(^(1)H-pyrazol-4-yl)-1,3-phenylene)dipyridine(HL^(2)).Complexes C1~C4 were characterized by^(1)H and^(13)C NMR,electrospray ionization mass spectrometry(ESI-MS),elemental analysis,and IR spectroscopy.The X-ray diffraction analysis of C1∙2NO_(3)−revealed a Pd_(2)dimetallic clip-shaped structure which was synthesized by two bifunctional ligands doubly bridged by the[(bpy)Pd]_(2)dimetal units.Additionally,all of the complexes with NO_(3)−as counter anions exhibited high-efficiency catalytical performance in the Suzuki-coupling reaction attributed to the tunable impact and weak dinuclear Pd(Ⅱ)···Pd(Ⅱ)intramolecular bonding interaction.
基金supported by the National Natural Science Foundation of China (No.91127039, 21471011)the Importation and Development of HighCaliber Talents Project of Beijing Municipal Institution~~
文摘This work reported a convenient method for the preparation of enantiomerically pure 6-aryl-2,2＇-dihydroxy-1, l＇- binaphthyl derivatives starting from the commercially available （R）-2,2＇-hydroxy-l, l＇-binaphthyl [（R）-I] via bromi- nation, hydrolysis and Suzuki cross coupling reaction. This novel synthetie method was characterized with high re- gioselectivity, simple operation, mild reaction conditions, and excellent yield （up to 73%）. On the other hand, we synthesized the target unknown compounds, which were confirmed by IR, 1H NMR, 13C NMR, MS and elementary analysis.
文摘This paper describes the synthesis and free radical polymerization of 2,5 bis(4′ alkyloxyphenyl)styrene(M n ) for mesogen jacketed liquid crystal polymers(MJLCPs), where p terphenyl subsituted by alkoxy groups at both ends was used as mesogenic unit. Because of the absence of the polar linkage groups, such as —COO— or —CONH— as employed in the previous reported MJLCPs, M n is believed to be polymerized easily by both free radical polymerization and ionic polymerization. The chemical structure of M n was proved by 1H NMR, mass spectrometry and elementary analysis. Their phase transition and liquid crystallinity were characterized by DSC and POM. Although M 1, M 2, M 3 and M 4 exhibited monotropic nematic mesophase, M 5 displayed enantiotropic nematic mesophase presumably because of its decreased melting transition temperature. All monomers were easily polymerized to moderately high molecular weight polymers. At elevated temperature above T g, poly[2,5 bis(4′ alkoxyphenyl)styrene] showed a very stable mesophase. The formed birefrigence did not disappear until thermal decomposition started. Compared to other MJLCPs, the polymers reported here have much higher thermal stability. [WT5HZ]
