【摘要】 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310nm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.更多还原

【Abstract】 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 photodimerization behavior of the coumarin derivative.The characteristic UV absorption and also the photodimerization of HMPC,which was irradiated by UV light(λ>310 nm),was effectively changed in different pH solutions.The photodimerization experiments showed that in the neutral solution the dimerization reaction rate was most rapid followed by that in the alkaline solution and it was the slowest in the acidic solution at the same concentration.更多还原