水杨基荧光酮-表面活性剂-羟丙基-β-环糊精体系荧光反应机理初步探讨
On the Mechanism of the Fluorescence Reaction System of Salicylfluorone-Surfactant-Hydroxypropyl-β-cyclodextrin
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摘要: 对表面活性剂(SF)与羟丙基-β-环糊精(HP-β-CD)共存时水杨基荧光酮(SAF)荧光体系的反应机理进行了研究。结果表明:SF的加入使SAF溶液的荧光有不同程度的增强,其中非离子型SF(如Triton X-100及OP)的增敏作用明显高于离子型SF,推断其原因为SF分子中的醚氧基与SAF分子中的羟基间形成氢键所致。而当SF与HP-β-CD共存时,SAF的荧光增强更明显,而且也是以非离子型SF与HP-β-CD共存时增敏更高。其原因除了上述氢键的形成之外,SAF的苯基由于邻位羟基使其亲水性增强可被HP-β-CD的空腔所包络,而SF的烷基链进入空腔受到限制,刚性增强,导致荧光量子产率提高。Abstract: The mechanism of the fluorescence reaction system of salicylfluorone(SAF)-surfactant(SF)-hydroxypropyl-β-cyclodextrin (HP-β-CD) was studied. As shown by the experimental results: the fluorescence intensity of SAF was enhanced to different extents by the addition of SF, and most significant enhancement of intensity was given by non-ionic SF′s, such as Triton X-100, and OP; the cause for this effect was deduced as the formation of hydrogen bond between ethoxy groups of SF and hydroxy groups of SAF; the fluorescence intensity of SAF was enhanced to a greater extent by simultaneous addition of SF and HP-β-CD, and similarly greater extent of enhancement was caused by non-ionic SF′s; it was deduced that besides the formation of hydrogen bond as described above, the increase of fluorescence intensity was caused by the increase of hydrophilicity of SAF due to its ortho-OH groups leading to the wrapping and complexing of phenyl group of SAF by entering into the cavity of HP-β-CD molecule, and restricting the alkyl chain of SF from entering into the cavity, thus leading to increase of rigidity and raise of rate of production of fluorescence quanta.