Nitrodisulfides were reduced by SmI2/HMPA in anhydrous THF at room temperature to produce active intermediates (samarium thiolates and amides), which were 'living' double-anions and reacted smoothly with aldeh...Nitrodisulfides were reduced by SmI2/HMPA in anhydrous THF at room temperature to produce active intermediates (samarium thiolates and amides), which were 'living' double-anions and reacted smoothly with aldehydes or ketones to afford benzothiazolines in good yields under mild and neutral conditions.展开更多
A nitro group is a common fluorescence quencher,but its quenching efficiency can be easily affected by the surrounding environment.To date,there has been no systematic study on the effects of electronwithdrawing group...A nitro group is a common fluorescence quencher,but its quenching efficiency can be easily affected by the surrounding environment.To date,there has been no systematic study on the effects of electronwithdrawing groups on the quenching efficiency of nitro groups.Herein,by virtue of experimental validation and theoretical calculations,we found that strong electron-withdrawing groups,such as pyridinium and dicyanovinyl groups,are detrimental to the quenching effect of nitro groups.Decreasing the electron-withdrawing ability could restore the nitro group’s quenching effect.展开更多
o-Nitrophenylazide was reduced by SmI2 in anhydrous THF at room temperature to produce active intermediate 2 (samarium amide), "living" double-anion in situ which reacted smoothly with α，β-unsaturated ket...o-Nitrophenylazide was reduced by SmI2 in anhydrous THF at room temperature to produce active intermediate 2 (samarium amide), "living" double-anion in situ which reacted smoothly with α，β-unsaturated ketones to afford 2,3-dihydro-1H-1,5-benzodiazepines in good yields under mild and neutral conditions.展开更多
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
基金We thank the National Natural Science Foundation of China (Project! No.29872010)the Laboratory of Organometallic Chemistry,
文摘Nitrodisulfides were reduced by SmI2/HMPA in anhydrous THF at room temperature to produce active intermediates (samarium thiolates and amides), which were 'living' double-anions and reacted smoothly with aldehydes or ketones to afford benzothiazolines in good yields under mild and neutral conditions.
基金start-up funding from the State Key Laboratory of Bioactive Substance and Function of Natural Medicines,Institute of Materia Medica,Peking Union Medical College,CAMS Innovation Fund for Medical Sciences(CIFMS)(No.2017-I2M-4-005)。
文摘A nitro group is a common fluorescence quencher,but its quenching efficiency can be easily affected by the surrounding environment.To date,there has been no systematic study on the effects of electronwithdrawing groups on the quenching efficiency of nitro groups.Herein,by virtue of experimental validation and theoretical calculations,we found that strong electron-withdrawing groups,such as pyridinium and dicyanovinyl groups,are detrimental to the quenching effect of nitro groups.Decreasing the electron-withdrawing ability could restore the nitro group’s quenching effect.
基金We thank the National Natural Science Foundation of China (Project No.29872010) NSF of Zhejiang province for financial support.
文摘o-Nitrophenylazide was reduced by SmI2 in anhydrous THF at room temperature to produce active intermediate 2 (samarium amide), "living" double-anion in situ which reacted smoothly with α，β-unsaturated ketones to afford 2,3-dihydro-1H-1,5-benzodiazepines in good yields under mild and neutral conditions.
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.
