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The focus of this research is to combine both computational as well as experimental methods to study the non-covalent interaction between a selected set of proteins with small molecules. Experimentally, a mass spectrometric technique, recently known as electrospray mass spectrometry together with the computational aspect of this research, in the area of molecular modeling and quantum mechanics would be exercised.Due to the soft ionization nature of this process, electrospray (ES) mass spectrometry (MS) has been employed to study a broad class of large proteins and their non-covalent interaction with small structures, making it possible for the mass of these complexes to _be determined with an error of less than 0.1%. For this research, a set of proteins known as histones and a class of structures known as crown ethers were chosen. The ES technique allows the proteins to be prepared in an acidic medium that protonates the basic amino acids that have been exposed by the solvent. This process leaves the protein with a lot of positive charges thereby making the analysis with a single quadrupole mass spectrometer, Extrel ELQ 400 possible. The non-covalent complexation between the histones and the crown ethers is stabilized by hydrogen bonding therefore the positive charges of the protein remain unchanged. This bonding is made possible by the ability of crown ethers to bind ammonium ion or protonated amino groups. The mass of the protein which is divided by the number of its positive charges can be determined by a new kind of linear plot constructed from the ES data. The ion currents from the electrospray ionization technique is a representation of the non-covalent complexation of the histones and the crown ethers which can be observed in the mass spectra. Other information such as, the binding constants, can be obtained from the mass spectra. / Department of Chemistry

Thesis. 1978. Ph.D.--Massachusetts Institute of Technology. Dept. of Chemistry. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND SCIENCE. / Includes bibliographical references. / Ph.D.

*Please refer to dissertation for diagrams. / Part 1 describes the selective C(alpha)-(beta) bonds cleavage of a series of aliphatic ethers (RCH2OCH2R: R = Et, Pr, Bu, iBu and pentyl) by RhII(tmp) using PPh3 as the promoting ligand to give Rh(tmp)-alkyls bearing the C(beta)-substituent in 13-40% yields at 24°C. The rate and the yields of Rh(tmp)-alkyls decreased with increasing steric hindrance of ethers. Addition of bases such as KOtBu, CsOH.H2O and KOH as well as H2O further promoted the product yields of the reactions with n-butyl ether to 56-62%. The reaction between RhII(tmp) and the cyclic ether, oxepane, at 24°C for 1 day gave Rh(tmp)(CH2)5OCHO in 17% yield suggesting that Rh(tmp)OH is the key intermediate in the C-C cleavage step and presumably generated via the PPh3-, H2O-, and OH --assisted disproportionation of RhII(tmp).* / Secondly, the reductive dehydrogenation of Rh(tmp)H to RhII(tmp) was also observed. Rh(tmp)H reacted with KOH in benzene-d6 at 100°C for 1 hour to give RhII(tmp) in 30% yield. [Rh I(tmp)]- is proposed to form initially via the deprotonation of Rh(tmp)H with KOH and then reacts with the unreacted Rh(tmp)H to give Rh II(tmp) via electron transfer. Thirdly, the hydroxide-induced disproportionation of RhII(tmp) to RhIII(tmp)OH and [Rh I(tmp)]- has also been proposed.* / The objective of this thesis focuses on studies of selective, base-promoted aliphatic carbon(alpha)-carbon(beta) bond activation (CCA) of ethers with rhodium(II) and rhodium(III) meso-tetramesitylporphyrin complexes (Rh II(tmp) and Rh(tmp)I). The roles of potassium hydroxide in promoting the interconversions of rhodium porphyrin species (RhII(tmp), Rh(tmp)I, Rh(tmp)OH and Rh(tmp)H) will also be discussed. / Lai, Tsz Ho. / Adviser: Kin Shing Chan. / Source: Dissertation Abstracts International, Volume: 72-04, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 161-172). / 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 Company, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

by Roger Chun Wang Liu. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1996. / Includes bibliographical references (leaves 98-108). / ACKNOWLEDGEMENTS --- p.i / CONTENTS --- p.ii / ABBREVIATIONS --- p.v / LIST OF FIGURES --- p.vi / LIST OF TABLES --- p.vii / Chapter I. --- THE CHEMISTRY OF METALLO-PHTHALOCYANINES AND -NAPHTHALOCYANINES --- p.1 / ABSTRACT --- p.2 / Chapter 1. --- SANDWICH-LIKE BIS(PHTHALOCYANINATO)LANTHANIDE COMPLEXES / Chapter 1.1. --- Introduction --- p.3 / Chapter 1.2. --- Preparation of Substituted Phthalonitriles --- p.8 / Chapter 1.3. --- Condensation of Phthalonitrile --- p.9 / Chapter 1.4. --- Condensation of Substituted Phthalonitriles --- p.10 / Chapter 1.5. --- Spectroscopic and Electrochemical Properties --- p.12 / Chapter 1.6. --- Conclusion --- p.21 / Chapter 2. --- "SUBSTITUTED 2,3-NAPHTHALOCYANINES" / Chapter 2.1. --- Introduction --- p.22 / Chapter 2.2. --- Preparation of Alkyl-Substituted Dicyanonaphthalenes --- p.26 / Chapter 2.3. --- Preparation of Halo-Substituted Dicyanonaphthalenes --- p.30 / Chapter 2.4. --- Condensation of Alkyl-Substituted Dicyanonaphthalenes --- p.30 / Chapter 2.5. --- Condensation of Halo-Substituted Dicyanonaphthalenes --- p.35 / Chapter 2.6. --- Conclusion --- p.38 / Chapter 3. --- EXPERIMENTAL SECTION / Chapter 3.1. --- General Directions --- p.39 / Chapter 3.2. --- Preparation of Substituted Phthalonitriles --- p.40 / Chapter 3.3. --- Condensation of Phthalonitrile --- p.43 / Chapter 3.4. --- Condensation of Substituted Phthalonitriles --- p.44 / Chapter 3.5. --- Preparation of Alkyl-Substituted Dicyanonaphthalenes --- p.46 / Chapter 3.6. --- Preparation of Halo-Substituted Dicyanonaphthalenes --- p.49 / Chapter 3.7. --- Condensation of Alkyl-Substituted Dicyanonaphthalenes --- p.51 / Chapter 3.8. --- Condensation of Halo-Substituted Dicyanonaphthalenes --- p.52 / Chapter II. --- "SYNTHETIC STUDIES OF MIXED AZA-, OXA-, AND THIA-CROWN ETHERS" --- p.55 / ABSTRACT --- p.56 / Chapter 1. --- INTRODUCTION --- p.57 / Chapter 2. --- RESULTS AND DISCUSSION --- p.64 / Chapter 2.1. --- Preparation of Diols and Dithiols --- p.64 / Chapter 2.2. --- Preparation of Ditosylates --- p.66 / Chapter 2.3. --- 1:1 Cyclization -- Preparation of Monoaza- 15-crown-5 --- p.68 / Chapter 2.4. --- Crystal Structure of N-(4-methoxyphenyl) benzomonoaza-15- crown-5 (112) --- p.76 / Chapter 2.5. --- Complexation of Monoaza-15-crown-5 --- p.79 / Chapter 2.6. --- Conclusion --- p.80 / Chapter 3. --- MISCELLANEOUS SYNTHESES --- p.81 / Chapter 3.1. --- Preparation of Tetrabromodibenzo-24-crown-8 --- p.81 / Chapter 3.2. --- Complexation of Tetrabromodibenzo-24-crown-8 --- p.82 / Chapter 4. --- EXPERIMENTAL SECTION --- p.84 / Chapter 4.1. --- General Directions --- p.84 / Chapter 4.2. --- Preparation of Diols and Dithiols --- p.84 / Chapter 4.3. --- Preparation of Ditosylates --- p.88 / Chapter 4.4. --- 1:1 Cyclization -- Preparation of Monoaza- 15-crown-5 --- p.89 / Chapter 4.5. --- Complexation of Monoaza-15-crown-5 --- p.94 / Chapter 4.6. --- Preparation of Tetrabromodibenzo-24-crown-8 --- p.95 / Chapter 4.7. --- Complexation of Tetrabromodibenzo-24-crown-8 --- p.97 / REFERENCES AND NOTES --- p.98 / APPENDIX --- p.109

A study has been made on the irradiation induced grafting of MMA to PPE and cellulose subtrates in the presence of various solvents and Irgacure 819 photoinitiator, a new photoinitiator on the market at the commencement of this project. UV is the main irradiation source used. The grafting yields have been found to vary with parameters such as the subtrate types and thickness, MMA concentration, solvents used, Irgacure 819 concentration and UV doses. For the cellulose subtrate, good grafting yields were obtained only when solvents such as methanol and DMF were used. On the contrary, MMA could graft to PPE with or without solvents, although high grafting yields were achieved in the presence of methanol, DMF and other chlorinated solvents. The solvent effects on the grafting process of MMA to PPE and cellulose subtrates were attributed to the wetting and swelling effects by the solvents as well as the Trommsdorff effect. During the course of this study, a comparison in the performance between Irgacure 819 and other photoinitiators (PIs) was also carried out. A study was made of the UV radiation induced grafting of styrene to PPE subtrate with EP vinyl monomers and vinyl ethers as comonomers. The possibility of spontaneous polymerization of styrene/EP vinyl monomer mixtures under the influence of UV radiation was also investigated. Grafting yields were found to vary with the comonomer types and their concentrations, the presence or absence of solvents and additives such as Irgacure 819 photoinitiator, K185 cationic photoinitiator, mineral acids and CT complexes. In addition, the composition of grafted subtrates was studied by using the FT-IR spectroscopy technique / Doctor of Philosophy (PhD)

Plusieurs fluoroionophores dérivés de la coumarine 343 ont été synthétisés. Leurs propriétés photophysiques et complexantes ont été déterminées dans l'acétonitrile. Ce sont des systèmes donneur-accepteur conjugués, où le cation interagit avec l'accepteur. Nous attendons donc des déplacements bathochromes des spectres d'absorption et d'émission. L'étude de C343-crown, -benzocrown et -dibenzocrown, dérivés de l'éther-couronne aza 15-crown-5, nous a permis de montrer que la rigidification de la cavité complexante permettait d'augmenter la sélectivité pour les cations alcalino-terreux par rapport aux alcalins. Les constantes de stabilité déterminées pour les complexes formés avec le magnésium ne varient presque pas lorsque la couronne est modifiée, ce qui suggère que cette dernière ne participe pas significativement à la complexation. L'étude des propriétés complexantes de C343-dieta et -dimeta, qui ne possèdent pas d'éther-couronne, nous permet de vérifier cette hypothèse. Afin d'augmenter la stabilité des complexes par la formation de semi-cryptates, deux sondes dérivées de l'éther-couronne diaza 18-crown-6, possédant 2 fluorophores, sont synthétisées. La présence de deux fluorophores permet d'observer des effets photophysiques supplémentaires, et d'obtenir des complexes environ 100 fois plus stables que ceux formés par les fluoroionophores dérivés de l'éther-couronne aza 15-crown-5. Nous avons pour certains fluoroionophores complété les résultats obtenus en absorption UV-visible et en fluorescence par des études en infra-rouge, en RMN du proton et du carbone et en spectrométrie de masse avec ionisation par électrospray (ESI-MS). Ces deux dernières techniques nous ont apporté des informations sur la structure des complexes formés, notamment sur la participation de la couronne et du solvant à la complexation.

Fluorescent labeling of biological materials using small organic dyes is widely employed in the life sciences and have been used in a variety of applications that include diagnostics and imaging. Quantum dots have the potential to overcome problems encountered by organic molecules and have been exploited for applications in biological imaging and in single particle tracking studies. The dithiolane ring can be exploited to attach a diversity of organic compounds to CdSe–ZnS core–shell nanoparticles. The introduction of spectroscopic labels as trans-azobenzene chromophores offers the opportunity to quantify the average number of dithiolane anchoring groups attached to each quantum dot. The transition from monomeric ligands with a single dithiolane anchor to polymeric ligands with multiple dithiolane anchoring groups can be exploited to raise the number of chromophoric labels adsorbed on each quantum dot. Systems showing FRET have been developed on the basis of supramolecular association of BODIPY based dyes or quantum dots as donors and organic chromophores as acceptors. Amino - terminated dyes and quantum dots associate with the chromophores through an ammonium moiety on addition of acid, thereby bringing them closer. Addition of base increases back the fluorescence intensity of the donor completely because of the dissociation. However a similar system with quantum dots as donor, show a very small restoration of fluorescence possibly due to non-specific interaction. In the next project, introduction of spectroscopic labels, in the form of BODIPY dye within the ligands offered the opportunity to quantify the average number of dithiolane anchoring groups attached to each quantum dot. Both fluorescence resonance energy transfer and electron transfer mechanisms are responsible for the quenching of quantum dot fluorescence and unfortunately does not make the system suitable for pH sensing. In the final project, BODIPY-oxazine based fluorophore – photochrome dyad has been assembled by a connecting triazole ring, such that the emission of the former can be modulated by the electronic and structural changes caused by the photoinduced transformations of the later. Further experiments need to be conducted on the fluorophore – photochrome dyads to switch the luminescence of the former with optical inputs.

Thesis (Ph. D.)--University of Texas at Austin, 2001. / Vita. Includes bibliographical references. Available also from UMI/Dissertation Abstracts International.

Thesis (Ph. D.)--University of Hong Kong, 2002. / Includes bibliographical references (leaves 219-222).