几种β-二酮化合物及其互变异构体的光谱

Spectroscopy of Several β-Diketone Compounds and Their Tautomers

合成了 6种β-二酮化合物 :1 ,3-二 (4 -硝基苯基 ) -1 ,3-丙二酮 ,1 -(4 -硝基苯基 ) -3-(3-硝基苯基 ) -1 ,3-丙二酮 ,1 ,3-二 (3-硝基苯基 ) -1 ,3-丙二酮 ,1 ,3-二 (4 -氨基苯基 ) -1 ,3-丙二酮 ,1 -(4 -氨基苯基 ) -3-(3-氨基苯基 ) -1 ,3-丙二酮和 1 ,3-二 (3-氨基苯基 ) -1 ,3-丙二酮 .采用多种光谱法对其结构进行了鉴定 .测量了不同溶剂中β-二酮化合物的酮式含量 ,给出了酮式

Six β diketone compounds, 1,3 bis(4 nitrophenyl) 1,3 propanedione (1) , 1 (4 nitrophenyl) \{3 (3 nitrophenyl) 1,3 propanedione (2) \}, \{1,3 bis(3 nitrophenyl) 1,3 propanedione (3) \} \{1,3 bis(4 \}amimophenyl) 1,3 propanedione (4) , 1 (4 amimophenyl) 3 (3 amimophenyl) 1,3 propanedione (5) and 1,3 bis(3 amimophenyl) 1,3 propanedione (6) were synthesized. Their structures were characterized by IR, UV Vis, fluorescence and NMR spectroscopy. The percentage of keto tautomer, enol keto equilibrium constant and enol tautomer ratio of them were also determined. The percentage of keto tautomer is increased in the order from compound 1 to 3 and decreased in the order from compound 4 to 6, which show the effect of substituent on the tautomer. The results of enol tautomer ratio of compounds 2 and 5 indicated that b form of enol is slightly more favorable than its a form.