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【答案】应助回帖
anjie2009(金币+100, 博学EPI+1): ★★★很有帮助 非常感谢，要是能用一些正宗的英语就更好l了，有点太直白了，呵呵， 2012-02-29 19:49:22
Organic conjugated polymer development has a great significance and is developing rapidly in the latest 20 years with a important branch of fluorescent conjugated polymer, which is a composite material with a property of polymer and fluorescence. Ordinary fluorescent polymer is a copolymer consists of the appearance of huge conjugated system and phenyl or fluorenyl alternately. For the design of fluorescent polymer, bringing in the heteroatom supplies a new method. On one hand, orbital overlap of heteroatom and organic conjugated system changes the electric structure and then the photoelectric properties and their different properties of fluorescence result of the difference of electronegativity of heteroatom. On the other hand, because of the perfect material heterocyclic activity we can import some other groups and the combination of heterocycle polymer and can both track metabolism of materials in the cell and be used in the detection of biochemistry. Boron-dipyrromethene(BODIPY) flourescent material is a new fluorescent dye with a high rate of flourescent quantum yield, molar extinction coefficient and good photo-stability which avoid the disadvantages of the other fluorescent polymers such as acid-base sensitivity, short wavelength and optical instability. This paper study the spectrum property, optical and heat stability of these five fluorescent polymers, which is synthesized based on BODIPY, synthesize 2,6 – bromide BODIPY and coupling reaction. What’s more, we also synthesize six fluorescent polymers with electron-withdrawing group and compared with BODIPY with electron-donating group in fluorescence.
We also synthesize two fluorescent polymers with heterocycle structure (thiophene, furan) and study the solution and solid spectrum property, heat stability and the differences between monomer and polymer. The structure shows that the wavelength of emission and absorption of polymers with heterocycle structure has changed a bit. This mainly caused by salvation effect , interaction of heteroatom and dissolvent, that reduce the dissolubility of polymer with heterocycle structure in the organic dissolvent.Study the spectrum property, dissolubility, consistency and heat stability of three polymers with methyl, pentyl and 1-undecyl by bringing in alkyl with different carbon atom. The search shows that the lack of active group and the reduction of solvent effect have little effect on the wavelength of emission and absorption of polymers in different dissolvent.
After contrasts the differences of fluorescence and heat stability of BODIPY, bromide BODIPY and polymerized BODIPY we conclude that the import of bromine atom causes the redshift of fluorescent wavelength and at the same time reduce the rate of quantum yield of 50%. But comparing the monomer of polymer and bromine, polymer also has the redshift and the rate of quantum yield changes better. Thermal Gravimetric Analysis shows that the heat stability of polymer is better than BODIPY and monomer. Nuclear magnetic resonance of synthetic polymer, characterized the mass spectrum, characterized the synthetic polymer by nuclear magnetic resonance, measure the distribution of the molecular weight. |
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