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Estudo espectroscópico, eletroquímico e fotofísico de porfirinas supermoleculares como fotossensibilizadores / Spectroscopy, electrochemical and photophysical studies of supermolecular porphyrins as photosensitizersMarzano, Fernanda Lodi 12 February 2009 (has links)
Uma série de compostos de transferência de carga baseado em derivados de anilina (grupo doador) e N-alquilpiridínio (grupo receptor) foi preparada e ligada à periferia do anel porfirínico, gerando uma nova série de porfirinas supermoleculares, que foram caracterizadas por espectroscopia eletrônica, voltametria cíclica, espectroeletroquímica, fluorescência e fotólise relâmpago. Os compostos foram preparados no laboratório do Prof. Silviu Balaban, no Instituto de Nanotecnologia do Forschungszentrum Karlsruhe, visando o estudo da interação entre a porfirina e aqueles compostos de transferência de carga, particularmente o efeito da estrutura molecular sobre as as propriedades fotoquímicas. As porfirinas foram projetadas tendo como modelo o sistema antena de algumas bactérias verdes fotossintéticas, visando obter fotossensibilizadores mais eficientes acoplando processos de transferência de energia (efeito antena) para o sítio porfirínico ativo, aumentando a eficiência de absorção/conversão na região do visível, melhorando assim o aproveitamento da energia solar. De fato, os sensibilizadores porfirínicos supermoleculares que foram objeto de estudo desta tese, apresentaram apenas um eficiente mecanismo de transferência de energia intramolecular para o grupo porfirínico; e as ligações amida ou éster utilizadas para ligar os grupos parecem não influenciar significativamente a eficiência do efeito antena. Os estudos de fluorescência e de fotólise relâmpago indicaram que os estados excitados singlete e triplete de menor energia estão localizados na porfirina, e que não há competição significativa de processos paralelos de supressão do estado excitado, por exemplo pelo mecanismo redox, apesar dos potenciais serem termodinamicamente favoráveis. Porém, pode haver transferência de carga do grupo derivado de anilina para a porfirina oxidada após a injeção de elétrons fotoinduzida para o filme de TiO2 nanocristalino, melhorando o processo de separação de cargas. Em suma, os materiais porfirínicos apresentam características adequadas e potencialidade para uso como fotossensibilizadores em dispositivos fotoeletroquímicos e fotovoltáicos. / A series of charge-transfer compounds constituted by anilline and Nalkylpyridynium derivatives as donor and acceptor groups was prepared and bond to the meso-position of a porphyrin to get a new series of supermolecular porphyrins, that were characterized by UV-Vis and fluorescence spectroscopy, cyclic voltammetry, spectroelectrochemistry and flash-photolysis. The series of compounds were synthesized in the Prof. Silviu Balaban Lab, at the Forschungszentrum Karlsruhe Institute of Nanotechnology aiming the study of the properties coming out of the interaction of porphyrins and donor-acceptor charge-transfer complexes, particularly the influence of the molecular structure on the photophysical properties. The supermolecular porphyrins were designed using the antenna system of photosynthetic green bacteria as model, in order to obtain more efficient photosensitizers by enhancing the light harvesting efficiency of porphyrins incorporating the energy-transfer effect. In fact, the charge-transfer complexes bound to the porphyrin ring were shown to interact exclusively through energy-transfer, and the amide or esther used to bridge those components didnt influence significantly the efficiency of that process. The lowest excited state was found to be localized on the porphyrin ring in the singlet and triplet excited state, by fluorescence and flashphotolysis studies. More interestingly, the results indicated that there is no competition of parallel deactivation mechanisms, such as redox mechanism, even though the potentials are thermodynamically favorable. However, charge-transfer from the donor anilline derivatives to the oxidized porphyrin site can take place immediately after photoinduced injection of an electron to nanocrystalline TiO2, improving the charge-separation process. In conclusion, the supermolecular porphyrins exhibited suitable properties as photosensitizers in photoelectrochemical and photovoltaic devices.
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Desenvolvimento da química supramolecular de porfirazinas polimetaladas / Supramolecular chemistry of polymetallic porphyrazinesMatsumoto, Marcio Yuji 27 February 2009 (has links)
Nesta tese foram perseguidos novos avanços no campo das tetrapiridilporfirazinas supramoleculares polimetaladas, visando explorar a maior capacidade de conjugação eletrônica esperada para essa classe de compostos, e seus reflexos nas propriedades eletrônicas e eletroquímicas. Foram apresentadas novas rotas sintéticas para obtenção de tetra(3,4-piridil)porfirazinas centrometaladas coordenadas a complexos polipiridínicos de rutênio, MTRPyPz (M = Cu, Co). As propriedades espectroscópicas e eletroquímicas foram investigadas com o auxílio de técnicas de espectroscopia UV-Vis, Raman ressonante, voltametria cíclica, espectroeletroquímica e espectrometria de massas. Foram desenvolvidas aplicações em dispositivos amperométricos para determinação eletrocatalítica de substratos importantes nas indústrias, como nitrito, sulfito e ácido ascórbico. Os estudos também abrangeram a formação de compósitos das porfirazinas tetrarrutenadas com fullereno. Os nanomateriais híbridos apresentaram uma alta eficiência nos processos eletrocatalíticos com menor sobrepotencial no eletrodo, abrindo perspectivas interessantes de utilização em dispositivos moleculares / Research in supramolecular polymetallic tetrapyridylporphyrazines has been pursued in this Thesis, aiming the exploitation of the favorable electronic delocalization associated with conjugated aromatic rings, and its influence on the electronic and electrochemical properties. New synthetic routes have been developed for the preparation of tetra(3,4-pyridyl)porphyrazines containing Cu(II) and Co(II) ions in the center, and four chlorobis(2,2´bipyridine)ruthenium(II) complexes attached to the peripheral pyridyl groups. Their spectroscopic and electrochemical behaviors were investigated by means of UV-Vis and resonance Raman spectroscopy, cyclic voltammetry, spectroelectrochemistry and mass spectrometry. Applications in amperometric devices for determination of nitrite, sulfite and ascorbic acid were successfully developed. The thesis also focused on nanocomposites generated from the polymetallic porphyrazines and fullerene (C60). Such hybrid nanomaterials exhibited enhanced electrocatalytic activity associates with a significant decrease of overpotential, opening exciting perspectives of use in molecular devices
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Nanomateriais híbridos de porfirinas supramoleculares e nanoparticulas de ouro e suas aplicações em dispositivos amperométricos / Hybrid nanomateriais of supramolecular porphyrins and gold nanoparticles and its applications in amperometrics devicesYatsuzuka, Rebeca Evahides 26 October 2007 (has links)
Sistemas supermoleculares constituídos por compostos porfirínicos apresentam propriedades e aplicações interessantes na área de catálise, sensores molecular, fotoeletroquímica, dentre diversas outras aplicações. Catalisadores mais eficientes e seletivos para a oxidação de substratos orgânicos são de grande interesse tecnológico. Sistemas supramoleculares contendo metaloporfirinas podem ser ainda utilizados como materiais ativos de sensores para diversas substâncias químicas de grande interesse comercial e ambiental. Nanopartículas de ouro podem ser versáteis \"blocos de construção\" para obtenção de nanomateriais híbridos devido à possibilidade da funcionalização de sua superfície com diversos ligantes com propriedades específicas. Neste trabalho, uma nova série de porfirinas obtidas por montagem coordenativa de quatro complexos dinucleares de carboxilato de ródio (3TPyP-Rh) foi preparada e caracterizada por espectroscopia UV-vis, ressonância magnética nuclear, termogravimetria e voltametria cíclica. Filmes supramoleculares híbridos obtidos a partir de nanopartículas de ouro reativas e porfirinas (metaloporfirinas e a supermolécula, 3TPyP-Rh) foram preparadas sobre eletrodos de FTO. Esses eletrodos modificados tiveram suas propriedades eletrocatalíticas estudadas, tendo-se em vista a obtenção de novos sensores amperométricos e comprovar a possibilidade de se modificar as propriedades desse tipo de nanomateriais variando-se os ligantes pontes moleculares. / Supramolecular systems consisting by porphyrin derivatives present interesting properties and applications in catalysis, molecular sensors, photoelectrochemistry, among many other applications. Supramolecular systems constituted by metalloporphyrins can be explored as active materials of sensors for several chemical substances of commercial and environmental interest. Gold nanoparticles can be versatile \"building blocks\" for the preparation of hybrid nanomateriais due to possibility of functionalization with diverse ligands with specific properties. In this work, a new series of porphyrins was obtained by coordenative assembly of four acetate complexes of dirhodium (3TPyP-Rh) and characterized by eletronic spectroscopy, nuclear magnetic resonance, termogravimetric analysis and cyclic voltammetry. FTO electrodes were modified with films of hybrid supramolecular nanomaterials build-up from reactive gold nanoparticles and meso-tetrayridylporphyrin derivatives (metaloporphyrins and the supermolecule, 3TPyP-RH). The eletrocatalytic properties were studied aiming the preparation of new amperometrics sensor and to demonstrate the possibility of controlling the properties of this type of nanomaterials by varying the molecular multi-bridge ligands. We found out that the AuNP/metalloporphyrin nanomaterials films are electrochemically and electrocatalytic active for the oxidation of substrates of great commercial interest, as ascorbic acid, sulfite and peroxide of hydrogen.
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Propriedades supramoleculares de porfirinas polinucleares / Supramolecular properties of polynuclear porphyrinsAraki, Koiti 18 March 1994 (has links)
A síntese e a caracterização de uma série de porfirinas polinucleares, por meio de análise elementar, espectroscopia eletrônica e Raman ressonante, voltametria cíclica e espectroeletroquímica, são apresentadas nesta tese. Estas supermoléculas foram obtidas pela coordenação de quatro grupos Ru(edta)- ou Ru(bipY)2Cl+ aos resíduos piridínicos das meso-tetra(piridil)porfirinas base-livre e metaladas. As propriedades eletrocatalíticas, fotoquímicas e fotofísicas foram estudadas, dando especial atenção às propriedades supramoleculares resultantes da interação entre as porfirinas e os complexos de rutênio periféricos. Também, foi explorada a capacidade singular desses complexos de formar filmes. Estes materiais são excelentes condutores iônicos e eletrônicos, e se comportam como fotocondutores moleculares, possibilitando a conversão de energia luminosa em elétrica. A possibilidade de utilizar estes filmes na confecção de dispositivos, tais como retificadores, amplificadores e transístores, assim como, células fotoelétricas e fotoeletroquímicas, abre novas perspectivas na área da fotoeletrônica molecular. / The synthesis and characterization of a series of polynuclear porphyrins by elementary analysis, electronic and resonance Raman spectroscopy, cyclic voltanunetry and spectroelectrochemistry, are presented. Those supermolecules were obtained by attaching Ru( edta)- or Ru(bipY)2Cl+ groups to the four pyridine residues of the free-base or the metallated meso-tetra(pyridil)porphyrins. Their electrocatalytical, photochemical and photophysical properties were studied. Special attention were paid to the supramolecular properties resulting from the interaction of the porphyrin and the peripheral ruthenium complexes. The unusual ability of these complexes to form stable films was also explored. These materials are excellent ionic and electronic conductors and act as molecular photoconductors, converting light into electricity. The films can be used for the design of electronic devices such as rectifiers, amplifiers and transistors, as well as, of photoelectric and photoelectrochemical cells.
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Estudo de complexos polimetalados contendo espécies biologicamente Ativas de rutênio/dirutênio\" / Study of polynuclear metal complexes containing biologically active ruthenium/diruthenium unitsSilva, Leila Malta Henrique da 31 August 2005 (has links)
Os complexos de rutênio há algumas décadas são estudados visando à aplicação em medicina, catálise e fotoquímica. Particularmente, com interesse voltado para a área médica, novos compostos têm sido desenvolvidos para substituir a cis-platina no tratamento do câncer, uma vez que este medicamento atua numa gama restrita de tipos de tumores e apresenta efeitos colaterais. O objetivo deste trabalho de pesquisa foi obter compostos polinucleares que possam reunir, em uma única espécie, duas ou três unidades de rutênio biologicamente relevantes. Compostos já conhecidos pela potencialidade antitumoral própria - cis-[RuCl2(dmso)4] e [Ru2Cl(AcO)4] - foram escolhidos como unidades de construção. Os compostos 4,4´-bipiridina e a 4-cianopiridina foram utilizadas como ligantes de ponte para unir estas unidades. Duas rotas diferentes para a obtenção dos compostos polimetalados foram propostas, sendo a escolha dependente do ligante-ponte utilizado. Três complexos precursores foram preparados modificando-se procedimentos já descritos, e novos compostos - um monômero e quatro polimetalados -foram sintetizados. Todos os complexos obtidos foram caracterizados por meio de medidas de análise elementar (CHN), espectroscopia eletrônica (UV-VIS-NIR) de soluções e de sólidos, espectroscopia vibracional (IV), e análise termogravimétrica (TGA). A técnica de 1H RMN e medidas de susceptibilidade magnética também foram utilizadas em alguns casos. / Ruthenium complexes have been studied for some decades for use in Medicine, catalysis and photochemistry. Regarding applications in the medical field, new compounds have been developed to substitute cisplatin in cancer treatment, since it has side effects and works on a restricted range of tumours. The objective of this research was to obtain polinuclear compounds that could combine, in one single structure, two or three known biologically active ruthenium units. Compounds known to exhibit antitumoral activity - cis-[RuCl2(dmso)4] and [Ru2Cl(AcO)4] - were chosen as building blocks. The 4,4´-bipyridine and 4-cianpyridine compounds were used as bridging ligands to connect these units. Two different synthetic routes were designed to obtain the polinuclear compounds being the choice dependent of the bridging ligand. Three precursors were prepared by modified - were synthesized. All obtained compounds were characterised by elemental analysis (CHN), electronic spectroscopy (UV-VIS-NIR) in solutions and solid state, vibrational spectroscopy (IR), and thermogravimetric analysis (TGA). The 1H NMR technique and magnetic susceptibility measurements were also used in some cases.
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DNA SELF-ASSEMBLY DRIVEN BY BASE STACKINGLongfei Liu (6581096) 10 June 2019 (has links)
<p>DNA nanotechnology has provided programming construction of
various nanostructures at nanometer-level precision over the last three
decades. DNA self-assembly is usually implemented by annealing process in bulk
solution. In recent several years, a new method thrives by fabricating
two-dimensional (2D) nanostructures on solid surfaces. My researches mainly
focus on this field, surface-assisted DNA assembly driven by base stacking. I
have developed methods to fabricate DNA 2D networks via isothermal assembly on
mica surfaces. I have further explored the applications to realize quasicrystal
fabrication and nanoparticles (NPs) patterning.</p><p><br></p>
<p>In this dissertation, I have developed a strategy to assemble DNA
structures with 1 or 2 pair(s) of blunt ends. Such weak interactions cannot
hold DNA motifs together in solution. However, with DNA-surface attractions,
DNA motifs can assemble into large nanostructures on solid surface. Further
studies reveal that the DNA-surface attractions can be controlled by the
variety and concentration of cation in the bulk solution. Moreover, DNA
nanostructures can be fabricated at very low motif concentrations, at which
traditional solution assembly cannot render large nanostructures. Finally,
assembly time course is also studied to reveal a superfast process for
surface-assisted method compared with solution assembly.</p><p><br></p>
<p>Based on this approach, I have extended my research scope from 1D to 2D
structures assembled from various DNA motifs. In my studies, I have
successfully realized conformational change regulated by DNA-surface
interaction and steric effect. By introduction of DNA duplex “bridges” and
unpaired nucleotide (nt) spacers, we can control the flexibility/rigidity of
DNA nanomotifs, which helps to fabricate more delicate dodecagonal quasicrystals.
The key point is to design the length of spacers. For 6-point-star motif, a
rigid structure is required so that only 1-nt spacers are added. On the other
hand, 3-nt spacers are incorporated to enable an inter-branch angle change from
60° to 90° for a more flexible 5-point-star motif. By tuning the ratio of 5 and
6 -point-star motifs in solution, we can obtain 2D networks from snub square
tiling, dodecagonal tiling, a
mixture of dodecagonal tiling and triangular tiling, and triangular tiling.</p><p><br></p>
Finally,
I have explored the
applications of my assembly method for patterning NPs. Tetragonal and hexagonal
DNA 2D networks have been fabricated on mica surfaces and served as templates.
Then modify the surfaces with positively-charged “glues”, <i>e.g.</i> poly-L-lysine (PLL) or Ni<sup>2+</sup>. After that, various
NPs have been patterned into designated lattices, including individual DNA
nanomotifs, gold NPs (AuNPs), proteins, and silica complexes. Observed NP
lattices and fast Fourier Transform (FFT) patterns have demonstrated the DNA
networks’ patterning effect on NPs.
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ENGINEERED 3D DNA CRYSTALS: CHARACTERIZATION, STABILIZATION AND APPLICATIONSZhe Li (6581093) 10 June 2019 (has links)
In recent years, DNA nanotechnology has emerged as one of the most
powerful strategies for bottom-up construction of nanomaterials. Due to
the high programmability of DNA molecules, their self-assembly can be
rationally designed. Engineered 3D DNA crystals, as critical products
from the design of DNA self-assembly, have been proposed as the
structural scaffolds for organizing nano-objects into three-dimensional,
macroscopic devices. However, for such applications, many obstacles
need to be overcome, including the crystal stability, the
characterization methodology, the revision of crystal designs as well as
the modulation of crystallization kinetics. My PhD research focuses on
solving these problems for engineered 3D DNA crystals to pave the way
for their downstream applications.<br>In this thesis, I started by
enhancing the stability of engineered 3D DNA crystals. I developed a
highly efficient post-assembly modification approach to stabilize DNA
crystals. Enzymatic ligation was performed inside the crystal lattice,
which was designed to covalently link the sticky ends at the crystal
contacts. After ligation, the crystal became a covalently bonded 3D
network of DNA motifs. I investigated the stability of ligated DNA
crystals under a wide range of solution conditions. Experimental data
revealed that ligated DNA crystals had significantly increased
stability. With these highly stabilized DNA crystals, we then
demonstrated their applications in biocatalysis and protein
encapsulation as examples.<br>I also established electron microscope
imaging characterization methods for engineered 3D DNA crystals. For
crystals from large-size DNA motifs, they are difficult to study by
X-ray crystallography because of their limited diffraction resolutions
to no better than 10 Å. Therefore, a direct imaging method by TEM was
set up. DNA crystals were either crushed or controlled to grow into
microcrystals for TEM imaging. To validate the imaging results, we
compared the TEM images with predicted models of the crystal lattice.
With the advance in crystal characterization, DNA crystals of varying
pore size between 5~20 nm were designed, assembled, and validated by TEM
imaging.<br>The post-assembly ligation was further developed to prepare
a series of new materials derived from engineered 3D DNA crystals,
which were inaccessible otherwise. With the directional and spatial
control of ligation in DNA crystal, I prepared new DNA-based materials
including DNA microtubes, complex-architecture crystals, and an
unprecedented reversibly expandable, self-healing DNA crystal. The
integration of weak and strong interactions in crystals enabled a lot of
new opportunities for DNA crystal engineering.<br>In the final chapter,
I investigated the effect of 5’-phosphorylation on DNA crystallization
kinetics. I found that phosphorylation significantly enhanced the
crystallization kinetics, possibly by strengthening the sticky-ended
cohesion. Therefore, DNA crystals can be obtained at much lower ionic
strength after phosphorylation. I also applied the result to controling
the morphology of DNA crystals by tuning the crystallization kinetics
along different crystallographic axes. Together with previously methods
to slow down DNA crystallization, the ability to tune DNA
crystallization kinetics in both ways is essential for DNA crystal
engineering.
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Synergistic effects in clathrate selectivitySayed, Amina January 2012 (has links)
Thesis (MTech (Chemistry))-- Cape Peninsula University Technology, 2012 / The inclusion behaviour of a series of hydroxyl hosts with a variety of liquid guests has been
investigated. The host 9-(4-methoxyphenyl)-9H-xanthen-9-ol (A1), C20H16O3, forms
inclusion compounds with aniline (ANI), 3-picoline (3PIC), morpholine (MORPH), Nmethylacetamide
(NMA) and N-methylformamide (NMF). Their structures have been
elucidated and correlated with their thermal behaviour. The inclusion compounds A1ANI
and A1MORPH were successfully solved in space group P21/c, whereas A13PIC was
solved in 𝑃ī. Non-isothermal kinetics of desolvation were performed for A13PIC and
A1MORPH. The packing of A13PIC and A1MORPH is characterized by (Host)(Guest)
hydrogen bonds, whereas A1ANI is stabilised by (Host)(Host) hydrogen bonding. Three
structures were obtained for the host A1 and the guest N-methylacetamide, with structural
formulas of C20H16O3
C3H7NO (A1NMA), C20H16O3
2C3H7NO (A12NMA) and
2C20H16O3
2C3H7NO (2A12NMA). The packing of A1NMA, A12NMA and 2A12NMA
are characterized by (Host)-OHO-(Guest) and (Guest)-NHO-(Guest) hydrogen bonds,
which gave hydrogen bonding patterns of 𝐶2
2(7), 𝐶3
3(11) and 𝐶4
2(11) respectively. The hydrate
A1NMFH2O was successfully solved in the triclinic space group 𝑃ī. The A1NMFH2O
hydrogen bond pattern may be described according to Etter’s notation as 𝑅4
2(8) and 𝑅6
6(16).
The host 9-(3-methoxyphenyl)-9H-xanthen-9-ol (A2), C20H16O3, forms inclusion compounds
with morpholine (A2MORPH), N-methylacetamide (A2NMA) and N-methylformamide
(A2NMF), with host-guest ratios 1:1. The crystal structure of the apohost was solved in Pbca
with Z=8. The structures of A2MORPH and A2NMF were solved in 𝑃ī, whereas A2NMA
was solved in P21/n. The packing of these structures is stabilised by (Host)(Guest)
hydrogen bonds.
The host 5-(4-methoxyphenyl)-5H-dibenzo[a,d]cyclohepten-5-ol (A26), C22H18O2, forms
inclusion compounds with aniline (A26ANI) and morpholine (A26MORPH). A26MORPH
and A26ANI crystallised in the space groups Pc and 𝑃ī respectively. The packing of these
structures are characterized by (Host)-OHO-(Host) hydrogen bonding. A guest exchange
reaction was performed.
The host compounds 5-(4-chlorophenyl)-5H-dibenzo[a,d]cyclohepten-5-ol (C21H15OCl),
5-[3(trifluoromethyl)phenyl]-5H-dibenzo[a,d]cyclohepten-5-ol (C22H15OF3) and
5-(naphthalen-1-yl)-5H-dibenzo[a,d]cyclohepten-5-ol (C25H18O) form inclusion compounds
with morpholine. All three structures were solved in 𝑃ī with the host molecules hydrogen
bonded to the morpholine guests.
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Estudos estruturais de proteínas em solução por SAXS utilizando luz síncrotron / Structural Studies Proteins Solution SAXS Using Synchrotron LightFischer, Hannes 11 April 2005 (has links)
Os objetivos da tese são, investigar (i) as estruturas terciária e quaternária de diversas proteínas em solução e (ii) as mudanças conformacionais de proteínas induzidas por ligantes e/ou temperatura, variando-se a concentração dos mesmos, etc. A principal técnica utilizada foi a de espalhamento de raios X a baixos ângulos (no inglês SAXS de mall-angle X-ray scattering), associada a outras metodologias como cristalografia e modelagem de proteínas. As contribuições dos estudos realizados de várias proteínas de interesse científico foram as seguintes: (i) propôs-se pela primeira vez um modelo de um receptor nuclear (RXR) composto por dois domínios, um de ligação ao ligante e outro ao DNA; (ii) elucidou-se o estado configuracional da fosfo-enol-piruvato carboxoquinase em solução; (iii) foi determinado o efeito de agregação e mudança conformacional induzido por ligantesna isoenzima fosfofrutoquinase e (iv) determinou-se a estrutura em solução da interleucina humana 22 e propôs-se modelos de interação com seus receptores. Além disso, (i) foi desenvolvido um método para determinar o estado oligomérico de uma proteína em solução, em quaisquer condições de tampão e concentração, utilizando medidas de SAXS em escala relativa, e (ii) mostrou-se que a densidade das proteínas é uma função do seu peso molecular, contrariando conceitos clássicos, tendo as proteínas pequenas (< 20kDa) uma densidade mais elevada que as maiores. / The purpose of this thesis is to investigate (I) the tertiary and quaternary structure of several proteins in solution and (II) conformational changed that such proteins undergo when they bind to ligands or temperature, pH, etc. conditions are varied. The main experimental technique utilized in this study was Small Angle X-Ray Scattering (SAXS) associated to other techniques and approaches like protein crystallography and homology modeling. The main contributions related to this work are: (i) for the first time a model for a nuclear receptor (RXR) containing two domains was proposed, one DNA binding domain and one ligand binding domain; (ii) the oligomeric state of the phosphor-enol-pyruvate caboxykynase in solution was detennined; (iii) the conformation changed induced by ligants to the isoenzyme phosphofructokinase was determined and (iv) the solution structure of human interleukin revealed and a model with its receptor proposed. Additionally, (i) a method for determining the oligomeric state of a protein in solution under any buffer conditions and concentration using SAXS in relative scale is proposed and (ii) it was also shown that proteins density is a molecular weight dependent function, where small proteins with less than 20kDa have in average a larger density than bigger ones.
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Bond activation and supramolecular chemistry with iridium(III) porphyrins.January 2007 (has links)
Song, Xu. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (leaves 92-96). / Abstracts in English and Chinese. / Table of Contents --- p.i / Acknowledgements --- p.iii / Abbreviations --- p.iv / Abstract --- p.v / Chapter Part I --- Carbon-Carbon Bonds Activation (CCA) of Ketones by Iridium(III) Porphyrins / Chapter Chapter 1 --- General Introduction / Chapter 1.1 --- Carbon-Carbon Bonds Activation by Transition Metals --- p.1 / Chapter 1.2 --- Thermodynamic and Kinetic Considerations in CCA --- p.1 / Chapter 1.3 --- C-C Bonds Activation by Low Valent Transition Metal Complexes --- p.3 / Chapter 1.3.1 --- CCA in Strained System --- p.3 / Chapter 1.3.2 --- CCA Driven by Aromatization --- p.6 / Chapter 1.3.3 --- Chelation Assisted CCA --- p.8 / Chapter 1.4 --- C-C Bonds Activation by High Valent Transition Metal Complexes --- p.11 / Chapter 1.5 --- Previous Mechanistic Studies on CCA by High Valent Transition Metal Complexes --- p.14 / Chapter 1.6 --- Objective of the Work --- p.16 / Chapter Chapter 2 --- Carbon-Carbon Bonds Activation (CCA) of Ketones by Iridium(III) Porphyrins / Chapter 2.1 --- Introduction --- p.17 / Chapter 2.2 --- CCA of Aromatic Ketones with Iridium(III) Porphyrins --- p.17 / Chapter 2.2.1 --- CCA of Aromatic Ketones with Ir(III) Porphyrin Chloride --- p.17 / Chapter 2.2.2 --- CCA of Aromatic Ketones with Ir(III) Porphyrin Methyl --- p.20 / Chapter 2.2.3 --- Steric Effect on CCA with Ir(III) Porphyrins --- p.21 / Chapter 2.3 --- CCA of Aliphatic Ketones with Iridium(III) Porphyrins --- p.21 / Chapter 2.3.1 --- CCA of Unstrained Aliphatic Ketones with Ir(III) Porphyrins --- p.21 / Chapter 2.3.2 --- CCA of Cyclic Aliphatic Ketones with Ir(III) Porphyrins --- p.22 / Chapter 2.4 --- Summary --- p.23 / Chapter Chapter 3 --- Preliminary Mechanistic Studies of Carbon-Carbon Bonds Activation (CCA) / Chapter 3.1 --- Proposed Mechanism of CCA with Ir(III) Porphyrin Chloride --- p.24 / Chapter 3.2 --- Proposed Mechanism of CCA with Ir(III) Porphyrin Methyl --- p.27 / Chapter 3.3 --- Determination of CCA co-product in situ --- p.30 / Chapter 3.4 --- Summary --- p.31 / Experimental Section --- p.33 / References --- p.44 / List of Spectra I --- p.48 / Chapter Part II --- Supramolecular Chemistry of C6o with Ir(III) Porphyrin Methyl / Chapter Chapter 1 --- General Introduction / Chapter 1.1 --- Supramolecular Interactions --- p.62 / Chapter 1.2 --- Introduction of C6o --- p.67 / Chapter 1.3 --- Supramolecular Interactions between C6o and Metalloporphyrins --- p.70 / Chapter 1.3.1 --- Discovery of Supramolecular Interactions between C6o And Metalloporphyrins --- p.70 / Chapter 1.3.2 --- Development of C6o-Metalloporphyrin Supramolecular Structure and Application --- p.71 / Chapter 1.3.3 --- Investigation on C6o-Metalloporphyrin Bonding Nature --- p.73 / Chapter 1.4 --- Objective of the Work --- p.76 / Chapter Chapter 2 --- Supramolecular Interaction between C60 and Ir(III) Porphyrin Methyl / Chapter 2.1 --- Synthesis of C60-Ir(ttp)Me Complexes --- p.77 / Chapter 2.2 --- X-ray Structure Analysis of C60-Ir(ttp)Me Complexes --- p.78 / Chapter 2.3 --- 1H NMR Analysis of C60-Ir(ttp)Me Complexes --- p.83 / Chapter 2.4 --- 13C NMR Analysis of C60-Ir(ttp)Me Complexes --- p.84 / Chapter 2.5 --- Binding Constant of C60-Ir(ttp)Me Complexes Using UV-Vis Analysis --- p.85 / Chapter 2.6 --- Summary --- p.87 / Experimental Section --- p.88 / References --- p.92 / Appendix --- p.97 / List of Spectra II --- p.101 / Reprint of OM Paper --- p.112 / Supporting Information for Organometallics Paper --- p.118
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