4,4＇-dibromo-2-nitro-biphenyl and 4,4＇-dibromo-2,3＇-dinitro-biphenyl have been synthesized via nitration reaction with 4,4＇-dibromobiphenyl as the raw material. Three novel thiophene derivatives, 4, 4＇-di（4-hexy...4,4＇-dibromo-2-nitro-biphenyl and 4,4＇-dibromo-2,3＇-dinitro-biphenyl have been synthesized via nitration reaction with 4,4＇-dibromobiphenyl as the raw material. Three novel thiophene derivatives, 4, 4＇-di（4-hexyl-thiophen-2-yl）biphenyl, 4,4＇-di（4-hexyl-thiophen-2-yl）-2- nitro-biphenyl and 4,4＇-di（4- hexyl-thiophen-2-yl）-2,3＇-dinitrobiphenyl were synthesized through Stille coupling reaction, followed by polymerization in the presence of FeC13, respectively. UV-vis absorption spectra, fluorescence spectra, photoluminescence spectra and electrochemical properties of the polymers were investigated. And the band-gap （Eg）, HOMO orbital energy （EHCMO）, and LUMO orbital energy （EUJMO） of the polymers were calculated. Among the polymers, polymer PBTN and PBTD show lower band-gap （2.67 and 2.63 eV）, lower HOMO energy level （-5.38 and -5.4 eV） and broader wavelength （432 and 438 nm） than that of polymer PBTB （2.69 eV, -5.36 eV and 424 nm） with incorporation of one nitro group or two nitro groups in the main chain, respectively.展开更多
Heterogeneous catalysts have been developed for C-C coupling reactions,but stand low activity and always proceed under harsh conditions.Photocatalytic Stille cross-coupling reaction as a green catalytic method for C-C...Heterogeneous catalysts have been developed for C-C coupling reactions,but stand low activity and always proceed under harsh conditions.Photocatalytic Stille cross-coupling reaction as a green catalytic method for C-C bond formation is of great interest for a wide range of scientists but still lacks stable and highly efficient catalysts.Herein,we have designed an Au nanoparticle-graphitic carbon nitride heterojunction as an outstanding photocatalyst for artificial photosynthesis in Stille cross-coupling reaction.The interface effect between metal and semi.conductor makes electron rectify and prevents the recombination of electron-hole pairs.Moreover,the efficiency of Au nanoparticle catalysts could be adjusted by gold contents.Thus the turnover frequency(TOF)value reached the highest level of 788 h l over the optimal heterojunction catalyst.Most importantly,the C-C bond formation reaction has been proved to be carried out well under visible light irradiation,indicating the low-cost organic synthesis pro cess.Further analysis confirmed the stability and general application of our heterogeneous Au nano-heterojunctior catalyst.展开更多
A novel large thiophene-fused polycyclic aromatics 1 based on pyrene 5 has been synthesized, and its structure was confirmed by ^1H NMR, ^13C NMR, MS, UV-vis and elemental analysis. The key steps of the synthesis invo...A novel large thiophene-fused polycyclic aromatics 1 based on pyrene 5 has been synthesized, and its structure was confirmed by ^1H NMR, ^13C NMR, MS, UV-vis and elemental analysis. The key steps of the synthesis involved the Stille cross-coupling reaction and followed by selective β-β oxidative cyclization of pendant thienyl rings by FeCl3 under mild conditions.展开更多
基金Supported by the National Natural Science Foundation of China(No.21176193)
文摘4,4＇-dibromo-2-nitro-biphenyl and 4,4＇-dibromo-2,3＇-dinitro-biphenyl have been synthesized via nitration reaction with 4,4＇-dibromobiphenyl as the raw material. Three novel thiophene derivatives, 4, 4＇-di（4-hexyl-thiophen-2-yl）biphenyl, 4,4＇-di（4-hexyl-thiophen-2-yl）-2- nitro-biphenyl and 4,4＇-di（4- hexyl-thiophen-2-yl）-2,3＇-dinitrobiphenyl were synthesized through Stille coupling reaction, followed by polymerization in the presence of FeC13, respectively. UV-vis absorption spectra, fluorescence spectra, photoluminescence spectra and electrochemical properties of the polymers were investigated. And the band-gap （Eg）, HOMO orbital energy （EHCMO）, and LUMO orbital energy （EUJMO） of the polymers were calculated. Among the polymers, polymer PBTN and PBTD show lower band-gap （2.67 and 2.63 eV）, lower HOMO energy level （-5.38 and -5.4 eV） and broader wavelength （432 and 438 nm） than that of polymer PBTB （2.69 eV, -5.36 eV and 424 nm） with incorporation of one nitro group or two nitro groups in the main chain, respectively.
基金Supported by the National Natural Science Foundation of China(Nos.21722103,21931005,21720102002,and 21673140)the Projiect of the Shanghai Science and Technology Committee,China(No.19JC1412600)the Fund of the SJTU-MPI Partner Group.
文摘Heterogeneous catalysts have been developed for C-C coupling reactions,but stand low activity and always proceed under harsh conditions.Photocatalytic Stille cross-coupling reaction as a green catalytic method for C-C bond formation is of great interest for a wide range of scientists but still lacks stable and highly efficient catalysts.Herein,we have designed an Au nanoparticle-graphitic carbon nitride heterojunction as an outstanding photocatalyst for artificial photosynthesis in Stille cross-coupling reaction.The interface effect between metal and semi.conductor makes electron rectify and prevents the recombination of electron-hole pairs.Moreover,the efficiency of Au nanoparticle catalysts could be adjusted by gold contents.Thus the turnover frequency(TOF)value reached the highest level of 788 h l over the optimal heterojunction catalyst.Most importantly,the C-C bond formation reaction has been proved to be carried out well under visible light irradiation,indicating the low-cost organic synthesis pro cess.Further analysis confirmed the stability and general application of our heterogeneous Au nano-heterojunctior catalyst.
文摘A novel large thiophene-fused polycyclic aromatics 1 based on pyrene 5 has been synthesized, and its structure was confirmed by ^1H NMR, ^13C NMR, MS, UV-vis and elemental analysis. The key steps of the synthesis involved the Stille cross-coupling reaction and followed by selective β-β oxidative cyclization of pendant thienyl rings by FeCl3 under mild conditions.
