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Synthesis, characterization and application of thermo-responsive [1] pseudorotaxane prepared by slippage approachWong, Chi Hin 13 July 2017 (has links)
This thesis is divided into three sections. The first section of the thesis includes the synthesis and characterization of a catechol-containing [2]pseudorotaxane which established a model for pseudorotaxane formation prepared through slippage method. The pseudorotaxane formation is performed in different solvents at elevated temperature in a period of time and the progress of pseudorotaxane formations were monitored with 1H NMR spectroscopy. The [2]pseudorotaxane had been successfully synthesized in acetonitrile (MeCN) at 60 oC for 5 d with 29% yield. The second section of the thesis demonstrates the potential of the [1]pseudorotaxane to work as a nanovalve. The opening of valve had been investigated and quantified in the presence of external stimuli such as heat, ultrasound, pH and alternating magnetic field (AMF). Furthermore, a novel core-satellite Fe3O4 nanocomposite had been prepared for AMF responsive controlled drug released system. The cytotoxicity of the core-satellite Fe3O4 nanocomposite had also been investigated and quantified in human gingival epithelial cells and human epithelial cell line, FaDu, from a squamous cell carcinoma of the hypopharynx. The core-satellite Fe3O4 nanocomposite showed non-cytotoxicity at concentration lower than 200 μg/mL and 100 μg/mL towards HGEPs and FaDu respectively. The third section of the thesis illustrates the synthesis of a novel [1]pseudorotaxane from a signal compound which consists of a macrocycle and a coordination site through a slippage approach. The formation of mechanically interlocked molecules restricted the twisted intramolecular charge transfer (TICT) quenching process and an enhancement of fluorescence intensity was observed. With a potential to act as a fluorescent probe, the fluorescence and fluorescence-quenching nature of the [1]pseudorotaxane had been investigated and quantified in the presence of external stimuli such as base, acid and salt. Furthermore, a series of cations and anions had been screened. The results suggested that the [1]pseudorotaxane was a highly selective phosphate ion sensor and working with a linear operating mode.
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Synthetic studies towards type III-B rotaxane dendrimers.January 2013 (has links)
本論文敘述了 III-B類輪烷樹狀物的人工合成及其表徵。透過重覆(1) 經改良的 銅(I) 催化炔烴 -疊氮偶極環加成反應 (2) 生成醯胺鍵以及最後 (3) 格拉澤 -希偶聯反應合成第一代 (G1) 及第二初代 (G2 ’)IIIB類輪烷樹狀物。 銨鹽啞及冠醚被採用來組合成分支結構的偽輪烷。 III B類輪烷樹狀物被核磁共振波譜法及電噴霧離子化法-質譜所表徵。這項研究為 III-B類輪烷樹狀物合成研究提供不可或缺的雛型 。這項研究為超分子及高化學家開拓新的領域,給予他們研究III-B類輪烷樹狀物的特性及其生醫學和電子應用機會。 / In this thesis, the syntheses and characterizations of a series of Type III-B Rotaxane Dendrimers are described. First generation (G1) and prototypical second generation (G2’) Type IIIB Rotaxane Dendrimer, which incorporate rotaxane features as the branching units, were synthesized by employing consecutive (1) modified Copper-Catalyzed Alkyne-Azide Cycloaddition (CuAAC), (2) amide formation through stopper molecule and pseudorotaxanes, and (3) GlaserHay’s acetylene homo-coupling reaction. Pseudorotaxanes with ammonium thread and crown ether macrocycle were employed. The Type III-B Rotaxane Dendrimers were characterized by nuclear magnetic resonance (NMR) spectroscopy, electrospray ionisationmass spectrometry (ESI-MS). This study provides an indispensable prototype to the synthesis of novel Type III-B Rotaxane Dendrimer. It opened up great opportunity for supramolecular and polymer chemists to further explore the properties and biomedical and electronic application of the novel dendrimers. / Detailed summary in vernacular field only. / Ho, Kwok Wai. / "October 2012." / Thesis (M.Phil.)--Chinese University of Hong Kong, 2013. / Includes bibliographical references (leaves 49-51). / Abstracts also in Chinese. / Contents --- p.i / Acknowledgments --- p.ii / Abstract --- p.iii / Abbreviations and Acronyms --- p.v / Synthetic Studies Towards Type III-B Rotaxane Dendrimer / Chapter Chapter 1 --- Introduction / Chapter 1.1 --- Classification of Rotaxane Dendrimers --- p.2 / Chapter 1.2 --- Type II-B Rotaxane Dendrimer --- p.5 / Chapter 1.3 --- Application of Copper Catalyzed Alkyne Azide Cycloaddtion(CuAAC) in Rotaxane Synthesis --- p.8 / Chapter 1.4 --- Potential Application of Type III-B Rotaxane Dendrimer --- p.12 / Chapter 1.5 --- Aim of Project --- p.14 / Chapter Chapter 2 --- Synthetic Studies Towards of Type III-B Rotaxane Dendrimer / Chapter 2.1 --- Design and Synthesis of Type III-B Rotaxane Dendrimer --- p.15 / Chapter 2.2 --- Characterization of G1 and G2’ Type III-B Rotaxane Dendron/Dendrimer --- p.27 / Chapter 2.2.1 --- ¹H NMR Spectroscopy --- p.27 / Chapter 2.2.2 --- ¹³C NMR Spectroscopy --- p.32 / Chapter 2.2.3 --- Mass Spectrometry --- p.32 / Chapter 2.3 --- Conclusion --- p.38 / Chapter Chapter 3 --- Experimental Procedures / Chapter 3.1 --- General Information --- p.39 / Chapter 3.2 --- Experimental Procedures --- p.40 / References / Appendix / List of Spectra --- p.A1
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Part I, self-assembly, stability quantification, controlled molecular switching, and sensing properties of an anthracene-containing dynamic [2]rotaxane: Part II, substituent effect in imine-containing molecular tweezers. / Self-assembly, stability quantification, controlled molecular switching, and sensing properties of an anthracene-containing dynamic [2]rotaxane / Part II, substituent effect in imine-containing molecular tweezers / Substituent effect in imine-containing molecular tweezersJanuary 2010 (has links)
Wong, Wing Yan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 76-79). / Abstracts in English and Chinese. / Contents --- p.i / Acknowledgments --- p.iii / Abstract --- p.iv / Abbreviations and Acronyms --- p.vii / Publications Originated from the Work of this Thesis --- p.ix / Chapter Part I: --- "Self-Assemblyy Stability Quantification, Controlled Molecular Switching, and Sensing Properties of an Anthracene-Containing Dynamic [2]Rotaxane" / Chapter Chapter 1 - --- Introduction / Chapter 1.1 --- Definition of Rotaxane --- p.2 / Chapter 1.2 --- Dynamic Covalent Chemistry in Rotaxane Synthesis --- p.5 / Chapter 1.3 --- Thermodynamic Template --- p.6 / Chapter 1.4 --- Molecular Sensing Properties in Rotaxane --- p.10 / Chapter 1.5 --- Examples --- p.13 / Chapter Chapter 2 - --- Anthracene-Containing Dynamic [2]Rotaxane / Chapter 2.1 --- Background --- p.17 / Chapter 2.2 --- Modification and Design of Dynamic [2]Rotaxane --- p.18 / Chapter 2.3 --- Self-Assembly of Rotaxane and Synthesis of Components --- p.19 / Chapter 2.4 --- Characterization / Chapter 2.4.1 --- 1H NMR Spectroscopy --- p.21 / Chapter 2.4.2 --- 13C NMR Spectroscopy --- p.23 / Chapter 2.4.3 --- Mass Spectrometry --- p.24 / Chapter 2.4.4 --- X-Ray Crystallography --- p.25 / Chapter 2.4.5 --- UV/Visible Absorption and Fluorescence Spectroscopies --- p.26 / Chapter 2.5 --- Effect of External Stimuli / Chapter 2.5.1 --- Addition of Water --- p.29 / Chapter 2.5.2 --- Addition of Acid --- p.33 / Chapter 2.5.3 --- Addition of Salts --- p.38 / Chapter 2.5.4 --- Addition of Amines --- p.40 / Chapter 2.6 --- Conclusions --- p.43 / Chapter Part II: --- Substituent Effect in Imine-Containing Molecular Tweezers / Chapter Chapter 3 - --- Molecular Tweezers / Chapter 3.1 --- Introduction --- p.46 / Chapter 3.2 --- Synthesis --- p.48 / Chapter 3.3 --- Characterization of Molecular Tweezers / Chapter 3.3.1 --- 1H NMR Spectroscopy --- p.49 / Chapter 3.3.2 --- Mass Spectrometry --- p.51 / Chapter 3.4 --- Characterization of Molecular Tweezers / Chapter 3.4.1 --- 1H NMR Spectroscopy --- p.51 / Chapter 3.4.2 --- X-Ray Crystallography --- p.59 / Chapter 3.4.3 --- Mass Spectrometry --- p.60 / Chapter 3.4.4 --- UV/Visible Absorption Spectroscopy --- p.61 / Chapter 3.5 --- Conclusions --- p.63 / Chapter Chapter 4 - --- Experimental Procedures / Chapter 4.1 --- General Information --- p.64 / Chapter 4.2 --- General Synthetic Procedures for Molecular Tweezers (34-40) --- p.65 / Chapter 4.3 --- Experimental Procedures --- p.65 / Chapter 4.4 --- Determination of Binding Constant K --- p.73 / References --- p.76 / Appendix / List of Spectra --- p.A-l / List of Crystal Data --- p.A-2
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Studies on Inclusion Complexes of Cyclodextrin and Dyes; I.Synthesis and Properties of Dye Rotaxanes, II. Formation of Anisotropic SupremoleculesPark, Jong Seung 26 August 2005 (has links)
Supramolecular chemistry covers intermolecular interactions where non-covalent bonds are involved, and many of them are based on host-guest interactions. Cyclodextrins (CDs) are cyclic oligosaccharides consisting of 6-, 7- or 8-glucose units, which are called alpha-, beta- or gamma-CDs, respectively. They have hydrophobic interior and hydrophilic exterior, and are widely being used as hosts for various organic molecules. The formation of CD inclusion complexes with a variety of dyes has continuously drawn our interests, since CDs are readily available and have ability to include dye molecules altering their properties.
The present thesis covers the study of inclusion complexes of CDs and chromophore dyes, largely in two ways; rotaxane and pseudorotaxane. The stable rotaxane structure is achieved with the synthesis of dye rotaxane. The introduction of CD ring around azo chromophore provides a simple way to improve the solubility and stability of azo dye. We have shown that by incorporating proper compounds as a coupler, azo dye rotaxanes can be used as pH indicators and metal ion sensors. We have described the synthesis of novel acetylene dye rotaxane using the Pd-catalyzed reaction of Heck-Cassar-Sonogashira-Hagihara type. Its fluorescence properties in the solid state as well as in solutions are examined and compared with those of free dye. Free dye, which has tetra-carboxylic groups, is found to be highly sensitive to various metal ions, exhibiting high Stern-Volmer constants, K(SV). On the contrary, acetylene dye rotaxane exhibits much less quenching against various quenchers.
The appearance of fluorescent anisotropic structure has been observed by the formation of inclusion complex between acetylene dye and gamma-CD. Its structural nature is studied by various techniques, including fluorescence, fluorescence anisotropy, wide angle X-ray scattering (WAXD) and differential scanning calorimetry (DSC) measurements. Methyl orange, an acid azo dye, forms a dimeric inclusion complex with gamma-CD, resulting in the formation stable anisotropic aggregates. Several other azo dyes are found to form anisotropic supramolecule in the presence of gamma-CD, and their structural characteristic has been discussed in terms of the number and position of solubilizing groups.
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