【作者】 汪素芳；

【导师】 卫艳丽；

【作者基本信息】 山西大学 ， 分析化学， 2011， 硕士

【摘要】 第一章：简要介绍了环糊精,化学修饰环糊精以及它们的应用。综述了具有识别功能的环状分子、分子识别的研究方法及其发展概况,简单叙述了分子识别中的手性识别研究。第二章：在非除氧的p-环糊精(p-CD)体系中,1,2-二溴甲烷(1,2-DBE)可在室温下诱导萘普生对映体的室温磷光发射。核磁数据证明萘普生分子的萘环部分是从β-CD小口端进入空腔内,羧基部分与p-CD外部的羟基之间形成氢键定位在p-CD腔外。而1,2-DBE则作为一种空间填充剂从大口端处竞争进入β-CD的空腔,从而形成一种稳定的三元混合物。在此基础上,通过荧光法计算了各步的包合常数,进一步证明萘普生对映体和1,2-DBE可以同时进入p-CD的空腔中从而形成三组分包结物。时间分辨磷光光谱法表明萘普生对映异构体都表现出双指数衰减,它们的磷光寿命差异(Δτi/τi)分别为32.9%和34.4%。这表明p-CD/1,2-DBE体系中可以实现萘普生对映体的手性识别。最后,利用分子模拟在分子水平对萘普生对映体的手性识别加以辅证,其结果与实验结果一致。第三章：本章通过6-胺基-6-脱氧-,3-胺基-3-脱氧和2-胺基-2-脱氧-p-环糊精合成了2-,3-和6-位取代的S-萘普生-p-CD,利用13CNMR、HNMR、高分辨质谱和圆二色谱等手段对该2-,3-和6-位取代的S-萘普生-β-CD进行了表征。在此基础上,对化合物1的荧光和磷光性质进行了初步探讨,并比较研究了S-萘普生与S-萘普生-p-CD在不同介质中的荧光和磷光特性。实验表明S-萘普生能进入p-CD的空腔,从而增强其荧光和磷光发射。第四章：利用室温磷光光谱研究了S-NPX-CDs 1-3对有机客体小分子的选择性识别作用,有机客体小分子包括二溴甲烷、三溴甲烷、二碘甲烷、碘甲烷、四溴化碳、1,2-二溴乙烷、甲醛、溴代环己烷、甲烷、环己烷、甲酸、甲醇、乙醇、和乙酸。实验表明,二溴甲烷可以显著增强S-NPX-CDs 1的室温磷光信号,但对S-NPX-CDs2和3的诱导并不明显。据此,建立了测定痕量二溴甲烷的室温磷光法,并将其用于煤矿矿坑水中痕量二溴甲烷的检测,检测结果与气相色谱-质谱联用法测得的结果相符,进一步表明S-NPX-CDs 1可以作为选择性检测二溴甲烷的超分子受体。最后,通过核磁共振氢谱、圆二色谱、紫外吸收光谱和能量模拟计算等对S-NPX-CDs 1选择性识别二溴甲烷的机理进行了探讨。更多还原

【Abstract】 Chapter 1:The concept and application of cyclodextrin, modified cyclodextrin were introduced briefly. Summarized the different research technique of chiral discrimination and narrated the orgin and research development of chiral recognition simply.Chapter 2:Naproxen enantiomers possess strong room temperature phosphorescence (RTP) in (3-cyclodextrin (P-CD) system with a small amount of 1,2-dibromoethane (1, 2-DBE) under ambient conditions. The effects of pH, concentration ofβ-CD and 1, 2-DBE on the RTP of naproxen enantiomers have been investigated in detail. Time-resolved RTP spectroscopy shows that both naproxen enantiomers exhibit bi-exponential decay pattern with lifetimes ofτ1= 4.79±0.13 andτ2=1.51±0.096 ms for R-naproxen, andτ1= 6.67±0.15 andτ2= 2.13±0.061 ms for S-naproxen. The lifetime differences between these enantiomers areΔτ1=1.88 andΔτ2r=0.62 ms, indicating that chiral discrimination of naproxen enantiomers can be achieved inβ-CD/1,2-DBE system. Naproxen enantiomers can form stable complexes withβ-CD and 1,2-DBE in stoichiometric ratios of 1:1:2 and 1:1:1 (naproxen:β-CD:1,2-DBE) and the association constants are 3.20×103 M-4 and 2.43×103 M-3 for the S- and R-enantiomers respectively. The chiral discrimination of R-naproxen and S-naproxen is realized via their difference in interaction with the chiral cavity ofβ-CD due to their difference in stereochemical structure. Finally, molecular modeling is performed to determine the chiral recognition on a molecular level and the results are in good agreement with the experimental data.Chapter 3:S-naproxen-modified-β-CD (S-NPX-CDs 1-3) were synthesized by the reactions of (S)-(-)-naproxen with 6-amino-6-deoxy-,3-amino-3-deoxy-, and mono(2-amino-2-deoxy-altro).-β-CDs, respectively. All of them were characterized by HRMS and 1H and 13C NMR spectra. On this basis, the fluorescent and phosphorescent properties of 1 were studied preliminary. The fluorescent and phosphorescent properties of S-naproxen and S-naproxen-modified-β-CD in different medium were also compared, and the results showed that S-naproxen can enter intoβ-CD cavity, so the fluorescence and phosphorescence were enhance.Chapter 4:Firstly, the fluorescence and phosphorescence characteristics of S-NPX-CDs 1-3 were investigated. Then the molecular recognition of S-NPX-CDs 1-3 to small organic objective molecules were explored by RTP method, and the organic small molecules included dibromomethane, bromoform, isodiiodomethane, iodomethane, Carbon Tetrabromide,1,2-dibromomethane, formaldehyde, bromocyclohexane, methane, cyclohexane, formic acid, methanol, ethanol and acetic acid. Among them, only dibromomethane could significantly enhance the RTP signal of S-NPX-CD1, while it had no effect on S-NPX-CDs 2 and 3. Based on this, a RTP method for the determination trace dibromomethane was establised by S-NPX-CDs 1 as the receptor. Then it was applied to determine the content of dibromomethane in coal mine water and the results was in good agreement with the result of GC-MS method. Therefore, a potential RTP sensor of dibromomethane can be developed by S-NPX-CDs 1 as the receptor. Finally, the mechanism was investigated by 1HNMR, dichroism, UV absorption spectra and energy simulatione.更多还原