Preparation And Properties Of Functional Materials Containing Spiropyran Or Rhodamine Chromophore

When UV irradiates indoline spiropyran, the low-polar spiropyran converted into the open-ring merocyanine form. Photo-regulatable self-assembly systems could be realized through taking full advantage of the photoisomerization feature of spiropyran moieties.We synthized PHB16 and PG12, as well as PHB16ESP and PG12ESP which contain spiropyran moieties. First, the self assembly of PHB16 and PG12 was investigated by dissolving them in different solvents. It is found that the self-assembling ability of PHB16 is stronger than that of PG12. Then, the self-assembling ability of PHB16ESP and PG12ESP was studied by dissolving them in different solvents. The results show that PHB16ESP can self assemble in DMSO and PG12ESP can self assemble in toluene.According to the principles of Fluorescence Resonance Energy Transfer (FRET), we chose FITC as the donor, rhodamine B as the acceptor. Due to its unique structural feature, cyclodextrin can keep the donor and acceptor within the effective distance of the Forster energy transfer. This supramolecular complexs has applications in Hg2+ ion detection. For detecting Hg2+, cyclodextrin with thioureido moiety was synthesized as HOST, and the FITC-ADA as the GUEST. The supramolecular-complex HOST/GUEST was formed in aqueous solution. In the HOST/GUEST supramolecular-complex, the addition of Hg2+ can promote the formation of the open-ring state of the SRhB moieties and the excited energy of donor (in cyclodextrin) could be transfered to the acceptor (rhodamine B/Hg2+ complex linked on cyclodextrin). The efficiency of energy transfer of the supramolecular-complex HOST/ GUEST reaches 90.2%. This HOST/ GUEST can serve as a water- soluble ratiometric fluorescent sensor for Hg2+, and can be used in environment and biological detection.