A new porous organic polymer （POP） with high thermal stability and large surface area has been synthesized and applied in the preparation of Pd/POP catalyst. Pd/POP was characterized by XRD, TGA, SEM and TEM. The ca...A new porous organic polymer （POP） with high thermal stability and large surface area has been synthesized and applied in the preparation of Pd/POP catalyst. Pd/POP was characterized by XRD, TGA, SEM and TEM. The catalyst consists of highly dispersed palladium nanoparticles of 0.9--4 nm size on POP with a large surface area of 650 m2/g. It presents high catalytic activity for Suzuki-Miyaura and Sonogashira reactions. The catalyst was reus- able for three to five times without significant loss of activity.展开更多
We report a facile and tailored method to prepare globally twisted chiral molecular cages through tunable coordination of bis-bipyridine-terminated helicene ligands to a series of transition metals including Fe(Ⅱ), ...We report a facile and tailored method to prepare globally twisted chiral molecular cages through tunable coordination of bis-bipyridine-terminated helicene ligands to a series of transition metals including Fe(Ⅱ), Co(Ⅱ), Ni(Ⅱ) and Zn(Ⅱ). This system shows an efficient remote transfer of stereogenecity from the helicene core to the bipyridine-metal coordination sites and subsequently the entire cages. While the Fe(Ⅱ), Co(Ⅱ) and Ni(Ⅱ)-derived M_(2)L_(3)(M for metal and L for ligand) cages exhibit quasi-reversible redox features, the Zn(Ⅱ) analogues reveal prominent yellow circularly polarized luminescence. Interestingly,with the addition of Na_(2)SO_(4), the Zn_(2)L_(3)cages reassemble into sextuple-stranded Zn_(6)L_(6)(SO_(4))_(4)cages in which three Zn_(2)L_(2) units are bound together by four sulfates and further coalesced by offset inter-ligandπ-π interactions.展开更多
Main observation and conclusion A pair of new enantiomeric compounds,(R)/(S)-1,3,5-benzene-triyl-2,2',2”-tris(4,5-dihydrothiazole-4-carboxylic acid)(H3LRRR and H3LSSS)are synthesized in one step synthetic route w...Main observation and conclusion A pair of new enantiomeric compounds,(R)/(S)-1,3,5-benzene-triyl-2,2',2”-tris(4,5-dihydrothiazole-4-carboxylic acid)(H3LRRR and H3LSSS)are synthesized in one step synthetic route with high yield.Instant photochromism has been investigated to elaborate the photocatalytic decarboxylation of the dihydrothiazole derivative by electron paramagnetic resonance spectroscopy(EPR),photoluminescence(PL),FT-IR,high resolution mass spectra,X-ray photoelectron spectroscopy and UV-Vis spectroscopic techniques.The results indicate that the photochromic transformation is originated from the formation of the radical during the photocatalytic decarboxylation of the 4,5-dihydrothiazole-4-carboxylic acid units.展开更多
文摘A new porous organic polymer （POP） with high thermal stability and large surface area has been synthesized and applied in the preparation of Pd/POP catalyst. Pd/POP was characterized by XRD, TGA, SEM and TEM. The catalyst consists of highly dispersed palladium nanoparticles of 0.9--4 nm size on POP with a large surface area of 650 m2/g. It presents high catalytic activity for Suzuki-Miyaura and Sonogashira reactions. The catalyst was reus- able for three to five times without significant loss of activity.
基金supported by the National Key R&D Program of China (No. 2020YFA0908100)the National Natural Science Foundation of China (Nos. 92056110 and 22075180)the Science and Technology Commission of Shanghai Municipality (Nos. 18JC1415500, 195271040, 20JC1415000)。
文摘We report a facile and tailored method to prepare globally twisted chiral molecular cages through tunable coordination of bis-bipyridine-terminated helicene ligands to a series of transition metals including Fe(Ⅱ), Co(Ⅱ), Ni(Ⅱ) and Zn(Ⅱ). This system shows an efficient remote transfer of stereogenecity from the helicene core to the bipyridine-metal coordination sites and subsequently the entire cages. While the Fe(Ⅱ), Co(Ⅱ) and Ni(Ⅱ)-derived M_(2)L_(3)(M for metal and L for ligand) cages exhibit quasi-reversible redox features, the Zn(Ⅱ) analogues reveal prominent yellow circularly polarized luminescence. Interestingly,with the addition of Na_(2)SO_(4), the Zn_(2)L_(3)cages reassemble into sextuple-stranded Zn_(6)L_(6)(SO_(4))_(4)cages in which three Zn_(2)L_(2) units are bound together by four sulfates and further coalesced by offset inter-ligandπ-π interactions.
基金sponsored by the Natural Science Foundation of Shanghai(Grant No.19ZR1424900).
文摘Main observation and conclusion A pair of new enantiomeric compounds,(R)/(S)-1,3,5-benzene-triyl-2,2',2”-tris(4,5-dihydrothiazole-4-carboxylic acid)(H3LRRR and H3LSSS)are synthesized in one step synthetic route with high yield.Instant photochromism has been investigated to elaborate the photocatalytic decarboxylation of the dihydrothiazole derivative by electron paramagnetic resonance spectroscopy(EPR),photoluminescence(PL),FT-IR,high resolution mass spectra,X-ray photoelectron spectroscopy and UV-Vis spectroscopic techniques.The results indicate that the photochromic transformation is originated from the formation of the radical during the photocatalytic decarboxylation of the 4,5-dihydrothiazole-4-carboxylic acid units.
