Two photochromic compounds with the pyrazolonering as the photochromic functional structure, 2(1phenyl3methyl4benzoformylpyrazolone5)thiosemicarbazone(PMBPTSC) and 2(1phenyl3methyl4benzoformylpyrazolone5...Two photochromic compounds with the pyrazolonering as the photochromic functional structure, 2(1phenyl3methyl4benzoformylpyrazolone5)thiosemicarbazone(PMBPTSC) and 2(1phenyl3methyl4benzoformylpyrazolone5)smethylthiosemicarbazone(PMBPMTSC), were synthesized and characterized by elemental analysis, MS, IR spectra, NMR spectra. The crystal structure of the photocolored product of PMBPTSC was determined by single crystal XRD analysis. The results show that the photochromic phenomenon is due to the photoisomerization from enol form to keto form. Their photochromic properties were studied by powderUV reflectance spectra under the irradiation of 200—380 nm light. The firstorder rate constants of the photocoloring reaction were found to be 780×10 -3 s -1 for compound 1A and 103×10 -3 s -1 for compound 2A.展开更多
Three new photoisomeric compounds: 1,3-diphenyl-4-benzal-5-pyrazolone 4-methylthiosemicarbazone (DPBP-MTSC), 1,3-diphenyl-4-(4′-methylbenzal)-5-pyrazolone 4-methylthiosemicarbazone (DP4MBP- MTSC), and 1,3-diphenyl-4...Three new photoisomeric compounds: 1,3-diphenyl-4-benzal-5-pyrazolone 4-methylthiosemicarbazone (DPBP-MTSC), 1,3-diphenyl-4-(4′-methylbenzal)-5-pyrazolone 4-methylthiosemicarbazone (DP4MBP- MTSC), and 1,3-diphenyl-4-(4′-bromobenzal)-5-pyrazolone 4-methylthiosemicarbazone (DP4BrBP-MTSC) were synthesized by direct condensation of pyrazolones and 4-methylthiosemicarbazone. Their struc- tures were confirmed using 1H NMR, IR, elemental analyses, and X-ray crystallographic analyses. The photoisomeric properties in the solid state were studied under UV light irradiation and the photo- isomerization phenomena were interpreted by the double proton-transfer mechanism. Moreover, the effects of different substituent groups at the 4-position of the benzal in the three compounds on the photoisomeric properties were discussed.展开更多
基金Supported by the National Natural Science Foundation of China
文摘Two photochromic compounds with the pyrazolonering as the photochromic functional structure, 2(1phenyl3methyl4benzoformylpyrazolone5)thiosemicarbazone(PMBPTSC) and 2(1phenyl3methyl4benzoformylpyrazolone5)smethylthiosemicarbazone(PMBPMTSC), were synthesized and characterized by elemental analysis, MS, IR spectra, NMR spectra. The crystal structure of the photocolored product of PMBPTSC was determined by single crystal XRD analysis. The results show that the photochromic phenomenon is due to the photoisomerization from enol form to keto form. Their photochromic properties were studied by powderUV reflectance spectra under the irradiation of 200—380 nm light. The firstorder rate constants of the photocoloring reaction were found to be 780×10 -3 s -1 for compound 1A and 103×10 -3 s -1 for compound 2A.
基金Supported by the National Natural Science Foundation of China (Grant No. 20462007)University Scientific Research Program of Education Bureau, Xinji-ang Uygur Autonomous Region (XJEDU2004G01 and XJEDU2004E01)
文摘Three new photoisomeric compounds: 1,3-diphenyl-4-benzal-5-pyrazolone 4-methylthiosemicarbazone (DPBP-MTSC), 1,3-diphenyl-4-(4′-methylbenzal)-5-pyrazolone 4-methylthiosemicarbazone (DP4MBP- MTSC), and 1,3-diphenyl-4-(4′-bromobenzal)-5-pyrazolone 4-methylthiosemicarbazone (DP4BrBP-MTSC) were synthesized by direct condensation of pyrazolones and 4-methylthiosemicarbazone. Their struc- tures were confirmed using 1H NMR, IR, elemental analyses, and X-ray crystallographic analyses. The photoisomeric properties in the solid state were studied under UV light irradiation and the photo- isomerization phenomena were interpreted by the double proton-transfer mechanism. Moreover, the effects of different substituent groups at the 4-position of the benzal in the three compounds on the photoisomeric properties were discussed.
