This dissertation reports on the recent discovery that calix[4]pyrrole not only functions as an anion receptor, but also has the ability to act as an ion pair receptor. It was discovered that in the solid state large diffuse cations, such as Cs+ and imidazolium, will occupy the electron-rich cone-like cavity that is formed upon anion binding to the NH region of the calix[4]pyrrole core. Also discussed are efforts devoted to improving the anion binding ability of calixpyrroles and fine-tuning their inherent selectivity. This has been probed through a variety of structural modifications. One of the most attractive of the modification strategies currently being explored involves expansion of the central binding cavity by using higher order β-fluorinated calix[n]pyrroles; n = 5, 6, and 8. An advantage of β-fluorinated calix[4]pyrrole is that it shows enhanced anion binding affinities toward several anions compared to the parent calix[4]pyrrole. Fluorinated calixpyrroles have also shown an ability to extract anions from aqueous environments into organic media. An alternative strategy has been to attach “straps” resulting in bicyclic systems, which further define the binding cavity achieving higher affinity and anion selectivity. The binding interactions of calixpyrrole and it derivative have been quantified using analytical techniques, such as nuclear magnetic resonance spectroscopy and isothermal titration calorimetry. The results of these latter studies will be discussed herein. / text

This thesis describes the synthesis of acyclic, macrocyclic and, in particular, interlocked anion and ion-pair receptors and sensors. <strong>Chapter One</strong> will introduce the field of supramolecular chemistry with particular emphasis on areas which are pertinent to this thesis, including anion receptor design and templated synthesis of interlocked structures. <strong>Chapter Two</strong> focuses on the synthesis of new heteroditopic macrocycles functionalised with both cation and anion recognition sites and their incorporation into interlocked architectures. The affinity for a range of anions and ion-pairs is explored via ¹H NMR and UV-visible spectroscopy as well as by X-ray crystallography. <strong>Chapter Three</strong> details the incorporation of d- and f-metal luminescent reporter groups into an isophthalamide motif in order to construct acyclic, macrocyclic and [2]rotaxane receptors. <strong>Chapter Four</strong> investigates the synthesis of complex higher-order interlocked structures through post-synthetic modification of lower-order interlocked structures. <strong>Chapter Five</strong> explores the potential for fluorescent gold nanoparticle conjugates to act as luminescent and colourimetric sensors for chemical warfare agents (CWAs) by employing a fluorescent displacement assay technique.

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In Nature sophisticated molecular machines are responsible for the synthesis of essential biomolecules and natural biopolymers. Inspired by these natural prototypes, scientist have begun to developed artificial systems that are able to perform complex synthetic tasks. Selected state-of-the-art examples, are presented and categorised according to their synthetic function: systems, which can distinguish between substrates and can also be regulated to produce different products, systems that selectively conduct multistep cascade reactions in mixtures of different reactants and systems that operate in a processive and sequence-specific fashion (Introduction).Following these examples, inspired by the ribosome, the synthesis and operation of the first artificial small-molecule machines based on a rotaxane structure capable of performing sequence-specific synthesis of a tri- and tetrapeptide from a molecular template is described. These machines operate through native chemical ligation (NCL), using a macrocyclic cysteine catalyst that iteratively removes proteinogenic amino acids from the strand and transfers them to a peptide elongation site. Successful operation on small scale generated milligram quantities of the peptides with a single sequence, determined by tandem mass spectrometry, corresponding to the original order of the amino acid building blocks on the strand (Chapter 1). Based on these first prototypes the system was extended to molecular machines operating on polymeric tracks. In this context the limits of the NCL mechanism were explored and the concept of the machine operation was investigated on a model system containing a polystyrene backbone with multiple leucine units. Here, machines with an average number of up to five L-leucyl groups were successfully operated. These initial studies represent the groundwork for the operation on longer polymeric systems containing sequences of amino acids (Chapter 2). Machines operating through a native chemical ligation (NCL) mechanism are restricted by a number of limitations: the rate of the reaction, the length and structure of the synthesised peptide, the cleavage of the product and finally the fact that peptide synthesis occurs in a reversed fashion to ribosomal synthesis (from C to N terminus). To overcome those limitations the development towards a 2nd generation molecular machine based on a transacylation catalyst was envisioned. Since this type of catalyst operates via a series of transacylation steps, the size of the transition state is kept the same throughout the operation, allowing access to longer peptides with fewer structural restrictions. Model systems using a thiophenol catalyst and a 1,2,4-triazol catalyst have been investigated (Chapter 3).

At the end of this thesis, the 1H and 13C{ 1H} NMR spectra for all the new compounds and the crystallographic data are given as an Appendix. / Chapter 1 presents an overview of phthalocyanines and subphthalocyanines, including their general synthesis, properties, photosensitizing applications, and supramolecular chemistry. / Chapter 2 describes the synthesis and spectroscopic characterization of a series of subphthalocyanines axially substituted with an oligoethylene glycol chain [SPcB(OCH2CH2)nOH] (n = 3, 4) or a p-phenoxy oligoethylene glycol methyl ether chain [SPcBOC 6H4(OCH2CH2)nOCH3] (n = 2, 3). Their in vitro photodynamic activities toward HT29 human colorectal adenocarcinoma and HepG2 human hepatocarcinoma cells have also been investigated. In general, these compounds are essentially non-aggregated, resulting in a strong fluorescence emission and high efficiency to generate singlet oxygen. Being formulated with Cremophor EL, these subphthalocyanines function as efficient photosensitizers and exhibit a high photocytotoxicity. The phenoxy analogues show a relatively high photostability and are particularly potent toward these cell lines. / Chapter 3 reports the synthesis, spectroscopic characterization, and in vitro photodynamic activities of a new series of water-soluble subphthalocyanines. The photodynamic activities of these compounds against HepG2 and HT29 cells have also been evaluated. They exhibit high singlet oxygen quantum yields, but different degree of photostability, which greatly affects their photocytotoxicity. The relatively high photostability of the carboxy subphthalocyanine and its salts renders them highly photocytotoxic. / Chapter 4 describes the axial coordination of two subphthalocyanines having an axial pyridyl group with several tetrapyrrole derivatives, including zinc(II) and ruthenium(II) porphyrins and phthalocyanines. By using various spectroscopic methods and X-ray diffraction analyses, the formation of 1:1 hetero-dyads has been confirmed. The binding constants between the pyridyl subphthalocyanines and these metallotetrapyrrole derivatives have also been determined by a fluorescence titration method. / Chapter 5 presents the synthesis and spectroscopic characterization of a covalently linked subphthalocyanine-cyclodextrin conjugate. The host-guest interactions between this compound and a tetra-sulfonated porphyrin in aqueous medium have been investigated by various spectroscopic methods. This supramolecular system exhibits an efficient photo-induced energy transfer process from the excited subphthalocyanine core to the porphyrin moiety. This host-guest approach provides a new strategy to construct mixed subphthalocyanine and porphyrin systems, which have not been explored so far. / Chapter 6 reports the use of a series of zinc(II) and silicon(IV) phthalocyanines as photocatalysts for the photooxidation of olefins and 1-naphthol. These compounds are efficient photosensitizers producing singlet oxygen to form the oxidized products in high yields. The only exceptions are two dendritic silicon(IV) phthalocyanines which have a relatively low efficiency to generate singlet oxygen. Three photosensitizers have also been examined for their recyclability in the photooxidation of alpha-terpinene and furan-2-carboxylic acid. All of them can be recycled at least four times without a significant loss of catalytic activity. / This thesis reports our investigation of two versatile classes of functional dyes, namely phthalocyanines and subphthalocyanines, focusing on their photosensitizing applications and supramolecular chemistry. / Xu, Hu. / Adviser: Dennis K. P. Ng. / Source: Dissertation Abstracts International, Volume: 70-06, Section: B, page: 3506. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references. / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.

Chi-Keung Lam. / "August 2002." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (p. 202-210). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.

Surface-enhanced Raman scattering (SERS) spectroscopy is a powerful analytical technique for ultrasensitive detection of chemicals and biomolecules. As the high sensitivity of SERS requires analytes to be in close contact with a plasmonic substrate, the detectionof analyte molecules with low chemical affinity towards the substrate is thus limited. Cucurbit[n]uril (CB[n]) exhibits strong and selective encapsulation of various guest molecules into its barrel-shaped cavity. In addition, it can function as a precise rigid spacer between metallic nanoparticles (NPs). The larger homologue CB[8] can simultaneously sequester two guest molecules to form ternary complexes, allowing for tailoring of the chemical environment of its cavity to trap specific analytes. CB[n] aggregated metallic NPs provide a powerful platform for the detection of a wide variety of molecules. However, the colloidal instability of this system requires the measurement to be finished within 60 min after the preparation of the substrate. In addition, in situ measurements may involve environments that affect such self-assembly processes. For example, the possible displacement of analytes in the nanogap by non-analyte moieties can give rise to fluctuating backgrounds. Therefore, a SERS substrate that can provide the same levels of detection and functionality but eliminates the need for aggregation is of great demand. This thesis mainly focuses on the preparation and characterisation of CB[n]-engineered nanostructures as SERS substrates with great colloidal stability, high SERS enhancements and sensitivities. Other applications of the prepared nanostructures such as peptide separation and high-performance catalysis are also discussed. In the first chapter, the historical development and the remaining challenges in the field of SERS are discussed. Three types of the most commonly used SERS substrates are introduced, followed by the introduction of rationally designed nanoplatforms for molecules with low chemical affinity towards metallic surfaces. In addition, CB[n] host guest complexation, examples of CB[n]-engineered nanostructures and the application of these nanostructures in SERS sensing are also discussed. The second chapter demonstrates the preparation of surface-bound CB[8] catenanes on silica NPs, where CB[8] is employed as a tethered supramolecular "receptor" to selectively capture target guest molecules. More specifically, CB[8] is threaded onto a methyl viologen (MV2+) axle and immobilised onto silica NPs with a surface density up to 0.56 nm$^{−2}$. Its use as an efficient and recyclable nanoplatform for peptide separation is demonstrated. The peptides captured by the catenanes can be released by reversible single-electron reduction of MV$^{2+}$. The entire process demonstrates high recoverability. Continued in the third chapter, a highly stable free-standing molecular sensor that exploits a catenane-engineered nanostructure is described. CB[8] is tethered onto spiky γ-Fe2O3@Au NPs in a similar approach, to collect target analytes from aqueous media. These target analytes can be detected with high sensitivities, on account of the high SERS enhancement (on the order of 10$^{8}$) of the spiky NPs. This CB[8] catenane-based molecular sensor provides a powerful SERS substrate that shows great promise in the detection of versatile chemicals, biomolecules, controlled substances and auxiliary diagnostics of various diseases. The fourth chapter introduces a facile preparation of monodispersed γ-Fe2O3@Au magnetic nanoraspberry NPs using a one-pot seeded growth method. The obtained nanoraspberry NPs show excellent colloidal stability and high SERS enhancement factors (on the order of 10$^{10}$). By immobilising a dense layer of CB[n]s onto the surface of nanoraspberry NPs, a new type of CB/Au NP SERS substrate is obtained. CB[n]s are located perpendicularly to the NP surface and their cavity maintain the capability to sequester guest molecules from aqueous media. More versatile molecules (both electron rich and electron deficient molecules) can thus be detected with high sensitivities. We envisage that this nanoraspberry-based molecular sensor will provide a powerful platform for SERS detection in various fields, such as chemical and biomolecule analysis, illegal drug detectionand pre-clinical/clinical diagnosis. The fifth chapter focuses on the preparation of CB[7]-based catalytic microreactors, where metallic NPs are immobilised onto microchannels via supramolecular interaction of methyl viologen@CB[7]. This microreactor exhibits remarkable catalytic activity on account of the high surface area to volume ratio of the microchannels and metallic NPs. Superior to most conventional heterogeneous catalytic reactions, separation post reaction and complicated recycling steps of the catalysts are not required. Moreover, CB[7] can complex a variety of metallic NPs onto its portal (e.g. gold, silver, palladium, quantum dot), providing a multifunctional in situ catalysis platform. In the end, a concluding chapter summarises the presented work, also giving a brief outlook of the potential future work.

Chan, Wing Shong Thierry. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 82-88). / Abstract also in Chinese. / Contents --- p.i / Acknowledgments --- p.iii / Abstract --- p.iv / Abbreviations --- p.vi / Chapter Chapter 1 - --- Dendronized Polymers and Supramolecular Polymers --- p.1 / Chapter 1.1 --- Introduction to Dendrons and Dendrimers --- p.1 / Chapter 1.2 --- Dendronized polymers --- p.4 / Chapter 1.2.1 --- Graft-from Method --- p.5 / Chapter 1.2.2 --- Graft-to Method --- p.7 / Chapter 1.2.3 --- Macromonomer Method --- p.8 / Chapter 1.2.3.1 --- Step Growth Polymerization --- p.9 / Chapter 1.2.3.2 --- Chain Growth Polymerization --- p.10 / Chapter 1.2.3.3 --- Living Chain Growth Polymerization --- p.11 / Chapter 1.3 --- Supramolecular Polymers --- p.12 / Chapter 1.4 --- Supramolecular Dendronized Polymers --- p.13 / Chapter Chapter 2 - --- Design of Supramolecular Dendronized Polymers --- p.18 / Chapter 2.1 --- Hydrogen Bonding --- p.19 / Chapter 2.1.1 --- Binary Characters of Hydrogen Bonding --- p.20 / Chapter 2.2 --- 2-Ureido-4[ 1H]-Pyrimidinone (UPy) --- p.22 / Chapter 2.3 --- Effects of Dendrons on Dimerization Constant of UPy --- p.25 / Chapter 2.4 --- Target Supramolecular Dendronized Polymers --- p.26 / Chapter Chapter 3 - --- Synthesis and Characterization of Supramolecular Dendronized Polymers --- p.28 / Chapter 3.1 --- Retro-Synthesis --- p.28 / Chapter 3.2 --- Synthesis of [G1]-[G3] Bifunctional Protected Monomers --- p.28 / Chapter 3.3 --- Characterization of Intermediates --- p.34 / Chapter 3.3.1 --- 1H NMR Spectroscopy --- p.34 / Chapter 3.3.2 --- 13C NMR Spectroscopy --- p.37 / Chapter 3.3.3 --- Mass Spectroscopy --- p.40 / Chapter 3.3.4 --- Size Exclusion Chromatography (SEC) --- p.40 / Chapter 3.4 --- Deprotection of [G1]-[G3] Biflmctional O-benzyl Protected Monomers --- p.41 / Chapter 3.5 --- Characterization of [G1]´ؤ[G3] Bifunctional Dendronized Monomers --- p.44 / Chapter 3.5.1 --- Characterization of [G1] Dendronized Di-UPy Monomer --- p.44 / Chapter 3.5.2 --- Characterization of [G2] Dendronized Di-UPy Monomer --- p.46 / Chapter 3.5.3 --- Characterization of [G3] Supramolecular Dendronized Di-Upy Polymer --- p.47 / Chapter 3.6 --- Conclusion --- p.49 / Chapter Chapter 4 - --- Properties of Supramolecular Dendronized Polymers --- p.50 / Chapter 4.1 --- Viscosity Measurement --- p.50 / Chapter 4.1.1 --- Introduction --- p.51 / Chapter 4.1.2 --- Viscosity Result At Room Temperature --- p.52 / Chapter 4.1.3 --- Viscosity Result At Different Temperatures --- p.53 / Chapter 4.1.4 --- Viscosity Result In Different Solvents --- p.55 / Chapter 4.2 --- Proton NMR --- p.56 / Chapter 4.3 --- Scanning Electron Microscopy --- p.59 / Chapter 4.4 --- Gelation Property --- p.61 / Chapter 4.5 --- Conclusion --- p.63 / Chapter Chapter 5 - --- Experimental Procedures --- p.66 / Chapter 5.1 --- General Information --- p.66 / Chapter 5.2 --- Experimental Procedures --- p.67 / References --- p.82 / NMR spectra --- p.89

Lau, Ting Fong Janet. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references. / Abstracts in English and Chinese. / Abstract --- p.iii / Abstract (in Chinese) --- p.v / Acknowledgment --- p.vii / Table of Contents --- p.ix / List of Figures --- p.xiii / List of Tables --- p.xix / List of Schemes --- p.xxi / Abbreviations --- p.xxiii / Chapter Chapter 1 --- Introduction / Chapter 1.1 --- General --- p.1 / Chapter 1.1.1 --- History of Phthalocyanines --- p.1 / Chapter 1.1.2 --- General Synthesis --- p.2 / Chapter 1.1.3 --- Properties and Usage of Phthalocyanines --- p.8 / Chapter 1.2 --- Phthalocyanines as Efficient Photosensitizers for Photodynamic Therapy --- p.9 / Chapter 1.2.1 --- Photophysical and Biological Mechanisms of Photodynamic Therapy --- p.10 / Chapter 1.2.2 --- Photosensitizers in Photodynamic Therapy --- p.13 / Chapter 1.2.2.1 --- First-Generation Photosensitizers --- p.13 / Chapter 1.2.2.2 --- Second-Generation Photosensitizers --- p.16 / Chapter 1.2.2.3 --- Phthalocyanine-Based Photosensitizers --- p.20 / Chapter 1.3 --- An Introduction on Supramolecular Chemistry --- p.27 / Chapter 1.3.1 --- Phthalocyanine-Based Supramolecular Systems --- p.28 / Chapter 1.3.2 --- Mixed Porphyrin-Phthalocyanine Supramolecular Assemblies --- p.31 / Chapter 1.4 --- Cyclodextrins as Building Blocks for Supramolecular Structures --- p.38 / Chapter 1.4.1 --- Background of Cyclodextrins --- p.38 / Chapter 1.4.2 --- Phthalocyanine-Cyclodextrin Supramolecular Systems --- p.41 / Chapter 1.5 --- Objectives of This Study --- p.47 / Chapter 1.6 --- References --- p.47 / Chapter Chapter 2 --- Permethylated β-Cyclodextrin Disubstituted Silicon(IV) Phthalocyanines / Chapter 2.1 --- Introduction --- p.55 / Chapter 2.2 --- Results and Discussion --- p.57 / Chapter 2.2.1 --- Preparation and Characterization --- p.57 / Chapter 2.2.2 --- Electronic Absorption and Photophysical Properties --- p.62 / Chapter 2.2.3 --- In vitro Photodynamic Activities --- p.66 / Chapter 2.3 --- Conclusion --- p.73 / Chapter 2.4 --- Experimental Section --- p.73 / Chapter 2.4.1 --- General --- p.73 / Chapter 2.4.2 --- Photophysical Measurements --- p.74 / Chapter 2.4.3 --- Synthesis --- p.75 / Chapter 2.4.4 --- Cell Lines and Culture Conditions --- p.83 / Chapter 2.4.5 --- Photocytotoxicity Assay --- p.83 / Chapter 2.4.6 --- ROS Measurements --- p.84 / Chapter 2.4.7 --- Microscopic Studies --- p.85 / Chapter 2.4.8 --- Subcellular Localization Studies --- p.85 / Chapter 2.5 --- References --- p.86 / Chapter Chapter 3 --- Unsymmetrically Substituted β-Cyclodextrin-Appended Silicon(IV) Phthalocyanines / Chapter 3.1 --- Introduction --- p.89 / Chapter 3.2 --- Results and Discussion --- p.90 / Chapter 3.2.1 --- Preparation and Characterization --- p.90 / Chapter 3.2.2 --- Electronic Absorption and Photophysical Properties --- p.94 / Chapter 3.2.3 --- In vitro Photodynamic Activities --- p.98 / Chapter 3.3 --- Conclusion --- p.107 / Chapter 3.4 --- Future Work --- p.108 / Chapter 3.5 --- Experimental Section --- p.108 / Chapter 3.5.1 --- General --- p.108 / Chapter 3.5.2 --- Synthesis --- p.109 / Chapter 3.6 --- References --- p.114 / Chapter Chapter 4 --- Construction of Mixed Phthalocyanine-Porphyrin Systems through Host-Guest Interactions in Aqueous Media / Chapter 4.1 --- Introduction --- p.117 / Chapter 4.2 --- Results and Discussion --- p.119 / Chapter 4.3 --- Conclusion --- p.132 / Chapter 4.4 --- Experimental Section --- p.132 / Chapter 4.5 --- References --- p.133 / Appendix A Determination of Binding Constants --- p.135 / Appendix B 1H and 13C{1H} NMR Spectra --- p.137 / Appendix C Mass Spectra --- p.151

Abstract not available