Three novel photoisomeric compounds of the 4-acyl pyrazolone derivants: Crystal structures and substituent effects on photo-isomerism in solid state  

作　　者：WANG JunHua LIU Lang LIU GuangFei GUO JiXi JIA DianZeng 

机构地区：[1]Institute of Applied Chemistry,Xinjiang University,Urumqi 830046,China

出　　处：《Science China Chemistry》2008年第7期661-668,共8页中国科学（化学英文版）

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)

摘　　要：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.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 (DP4MBPMTSC), and 1,3-diphenyl-4-(4′-bromobenzal)-5-pyrazolone 4-methylthiosemicarbazone (DP4BrBP-MTSC) were synthesized by direct condensation of pyrazolones and 4-methylthiosemicarbazone. Their structures 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 photoisomerization 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

关 键 词：PHOTOISOMERIZATION PYRAZOLONE PROTON-TRANSFER SUBSTITUTE effects 

分 类 号：O626[理学—有机化学]