香豆素-3-甲酰氯修饰聚酰胺-胺大分子的荧光性能研究

用香豆素-3-甲酰氯对聚酰胺-胺树状大分子末端修饰合成了树状大分子PAMAM-CMAC，经FTIR，1H-NMR分析确证了其结构。荧光分析表明，PAMAM-CMAC树状大分子具有强的荧光发光，荧光强度比聚酰胺-胺树状大分子荧光强度增加很多。其荧光强度受pH值、溶液浓度和溶剂等各种因素的影响，在酸性条件下，荧光强度受溶液pH影响较大;但在强碱性介质中，氢键被完全破坏，荧光强度明显减弱。pH在7.00～10.00之间时，荧光发光比较稳定。溶液浓度对荧光强度也有影响，浓度太大或太小，荧光强度都相应减小，而且浓度大的溶液比浓度小的溶液荧光猝灭的快。这与理论相一致。同时，随着溶剂极性的增加，荧光发射向长波方向移动。

Study on the Fluorescence of Poly (amidoamine) Dendrimers Decorated with Coumarin-3-Methyl Acyl Chloride on the Periphery

The polyamidoamine dendrimers, PAMAM CMAC, was synthesized by decorating PAMAM dendrimer with coumarin-3-methyl acyl chlorine on the periphery. The structures were characterized by FTIR and ^1H-NMR spectra. The fluorescence analysis indicated the PAMAM-CMAC exhibits strong fluorescence emission. The fluorescence intensity of PAMAM-CMAC is much higher than that of PAMAM dendrimer. The fluorescence intensity of PAMAM-CMAC was affected by pH, concentration and solvent. At a considerably big pH value range, the fluorescence emission of PAMAM-CMAC is comparatively stable. Meanwhile, the fluorescence emission of PAMAM-CMAC shifts to longer wavelength with the increase in solvent polarity.