7-羟基-4-甲基-8-(4'-甲基哌嗪-1'-基)-亚甲基香豆素的光二聚行为

通过Mannich反应在7-羟基-4-甲基香豆素的8-位上引入具有pH响应性能的4-甲基哌嗪的供电子哌嗪基团, 得到水溶性香豆素衍生物, 7-羟基-4-甲基-8-(4'-甲基哌嗪-1'-基)-亚甲基香豆素(HMPC), 利用哌嗪环上的叔胺给电子体系对酸碱的敏感特性调节HMPC的光二聚反应特征. 详细考察该香豆素衍生物在不同pH水溶液中的紫外光二聚性能, 紫外光谱分析显示, 通过调节HMPC水溶液的酸碱性可有效改变其紫外特征吸收; 在波长大于310 nm的紫外光照射下, 衍生物上的香豆素单元可进行光二聚, 并且紫外点光源光二聚反应实验表明, 其在中性水溶液中的反应速度最快, 其次为碱性条件中的反应, 最慢的则是酸性条件中的反应.

Photodimerization Behavior of 7-Hydroxy-4-methyl-8-(4'-methylpiperazin-1'-yl) Methylcoumarin

The water-soluble coumarin derivative 7-hydroxy-4-methyl-8-(4'-methylpiperazin-1'-yl) methylcoumarin(HMPC) was synthesized by the Mannich reaction between 7-hydroxy-4-methylcoumarin and N-methylpiperazine,which possesses an electrondonating piperazine group with pH responsivity.Since the piperazine group is a pH-sensitive electron donor,the resultant HMPC has interesting photophysical and photochemical properties in different pH solutions.We investigated the characteristic UV absorption and photodimerizatio...