去氧胆酸钠水溶液中4－二甲氨基查尔酮荧光的超常增强

ULTRA ORDINARILY HIGH ENHANCEMENT OF THE FLUORESCENCE OF 4-DIMETHYLAMINOCHALCONE IN AQUEOUS SODIUM DEOXYCHOLATE SOLUTION

去氧胆酸钠水溶液中４－二甲氨基查尔酮荧光的超常增强江云宝，王秀娟，林莉，黄贤智，许金钩（厦门大学化学系，现代分析化学研究所，厦门３６１００５）关键词双自由基激发态，荧光探针，胆酸型甾族表面活性剂，缔合类似于电子给体受体取代的芭类化合物，４－二甲基氨基...

The fluorescence intensity and maximum wavelength of 4-dimethylaminochalcone(DMAC)in aqueous solution are observed to increase with the concentration of sodium deoxycholate (SDOC), a steroidal surfactant,to their maxima and then decrease,while in thesolution of an aliphatic surfactant sedium laurate(NaL),both the parameters increase withincreasing NaL concentration and level off after micelle formation. Although the fluores-cence maximum wavelength of DMAC is shorter in SDOC system than that in NaL system,the fluorescence intensity is much higher in SDOC system. The ultraordinarily high enhancement of DMAC fluorescence in SDOC system is rationalized as being due to the aggregation of rigid SDOC molecule in aqueous solution. The SDOC aggregate provides DMAC with an also rigid microenvironment where the formation of the photoinduced nonemissivebiradical state P.of DMAC is hindered and thus the emission is much strongly enhanced.Before the formation of micelle,SDOC molecule is shown to exist mainly in dimer which forms a sandwich supramolecular complex with DMAC by an association constant of 9 3.2L/mol.