A preparação, caracterização e estudo de propriedades moleculares e supramoleculares de meso-tetrapiridilporfirinas modificadas com quatro complexos de cloro(bipiridina) platina(II) ligados às posições meta e para de ligantes piridínicos periféricos, foi objetivo desta tese. As supermoléculas isômeras foram isoladas no estado sólido e extensivamente caracterizados por meio de espectroscopia UV/VIS, FT-IR e RMN de Pt-195, assim como através de TGA e espectrometria de massa com ionização por spray de elétrons, ESI-MS, e técnicas de dissociação induzidas por colisão. Medidas de voltametria cíclica e de espectroeletroquímica foram realizadas para caracterizar os estados redox da porfirina central e dos complexos periféricos, mostrando uma semelhança entre as duas formas isômeras. A maior diferença, entretanto, foi observada nas suas propriedades estruturais, diagnosticadas por modelagem molecular, e refletidas na morfologia dos filmes obtida por meio de técnicas de microscopia de varredura por sonda, SPM, e através da associação com filmes de DNA, monitorada com o auxílio de técnicas de espectroscopia eletrônica e ressonância plasmônica de superfície, SPR. No último caso, o DNA foi imobilizado sobre a superfície do sensor de ouro, usando aminotióis adequados, sendo que a interação do isômero meta conduziu a uma resposta contrastante, relevando uma forte ligação com a cadeia do DNA, provavelmente nas proximidades das fendas estruturais menores desse biopolímero. A interação do isômero para com o DNA foi demasiadamente fraca para ser observada por meio de SPR. A associação molecular das porfirinas tetraplatinadas catiônicas com ftalocianinas aniônicas tetrassulfonadas conduziu à formação de pares iônicos em solução. O filme do isômero para imobilizado sobre eletrodo de carbono vítreo apresentou atividade na redução eletrocatalítica de nitrito. Os trabalhos realizados demonstraram que os novos sistemas supramoleculares derivados de porfirinas e complexos de platina proporcionam interessantes materiais híbridos inorgânico-biológicos contendo DNA e metais nobres, com potenciais aplicações em terapia fotodinâmica, sensoriamento e em dispositivos moleculares. / The synthesis, characterization and investigation of the molecular and supramolecular behaviour of meso-tetrapyridylporphyrins containing four chloro(bipyridine) platinum(II) complexes attached at the meta and para positions of the peripheral pyridine ligands is focused on this thesis. The isomeric supermolecules were isolated in the solid state, and extensively characterized by means of UV-visible, FT-IR and 195Pt NMR spectroscopy, as well as, by TGA and electrospray spectrometry associated with collision induced techniques. Cyclic voltammetry and spectroelectrochemical measurements were performed to characterize the redox sites on the porphyrin and peripheral complexes, revealing a close similarity between the two isomeric supermolecules. Major differences were observed on their structural properties, as demonstrated by means of molecular simulations, and by the morphology of the molecular films probed by SPM techniques, and also by their association with DNA films, which was monitored by means of SPR techniques. In the last case, DNA was first immobilized onto the surface of the gold sensor, using suitable aminothiols and the interaction of the meta-isomer led to a contrasting response, exhibiting a strong binding to the DNA chain, presumably at the proximity of the minor grooves. The interaction of the para-isomer with DNA was too weak to be probed by means of the SPR technique. Molecular association of the tetraplatinum porphyrin species, with tetrasulphonated phtalocyanines, leading to ion pairs in solution, was also investigated. The molecular film of the para-isomer immobilized over glass carbon electrode has shown activity in the electrocatalytic reduction of nitrite. This work on the supramolecular porphyrin platinum species provided new interesting approaches for generating hybrid biological-inorganic systems, containing DNA and noble metals, for sensing applications, and molecular devices.

Cette thèse se focalise sur le design, la synthèse et la caractérisation photophysiques de complexes de platine(II) neutres contenant un ligand chromophore tridenté et un ligand auxiliaire monodenté avec des groupes fonctionnels différents. De tels complexes montrent des changements drastiques de leurs propriétés de photoluminescence à cause de leur auto-assemblage, déclenché par l’établissement de faibles liaisons non covalents tels que l’empilement p-p et des interactions métallophiliques. Il a été démontré que ces complexes de platine(II) peuvent être attaché de manière covalente à des surfaces de silice et d’or mais aussi encapsulé dans des particules de polymère. Les propriétés d’autoassemblage de complexes de platine(II) amphiphiles ont également été étudiées en détails. Comprendre le comportement d’un complexe de platine dans un mélange de solvant nous a permis d’en apprendre plus sur le co-assemblage supramoléculaire de deux complexes de platine(II) différents. Cette approche conduit à la formation de fibres solvatochromiques avec des propriétés photophysiques spécifiques et réversibles. Les composés étudiés et leur auto-assemblage sonti ntéressant pour le développement de nouveaux matériaux fonctionnels aux applications sensoriels et réactives à certains stimuli. / This thesis focuses on the design, synthesis and the photophysical characterisation of luminescent neutral platinum(II) compounds containing a tridentate chromophoric ligand and a monodentate ancillary moiety with different functionalities. Such complexes exhibited drastic changes to their photoluminescence properties upon self-assembly, triggered by the establishment of weak noncovalent p-p stacking and metallophilic interactions. It was demonstrated that these platinum(II) complexes can be covalently attached to silicon and gold substrates but also encapsulated into polymer particles. The self-assembly properties of amphiphilic platinum(II) complexes have also been intensively studied. Understanding the behaviour of one complex in a solvent mixture allowed further investigation into the supramolecular co-assembly of two different platinum(II) complexes. This approach leads to the formation of solvatochromic fibers with specific and reversible phototophysical properties. The investigated compounds and their assemblies were useful for the development of novel functional materials for sensing or stimuli-responsiveness applications.

A preparação, caracterização e estudo de propriedades moleculares e supramoleculares de meso-tetrapiridilporfirinas modificadas com quatro complexos de cloro(bipiridina) platina(II) ligados às posições meta e para de ligantes piridínicos periféricos, foi objetivo desta tese. As supermoléculas isômeras foram isoladas no estado sólido e extensivamente caracterizados por meio de espectroscopia UV/VIS, FT-IR e RMN de Pt-195, assim como através de TGA e espectrometria de massa com ionização por spray de elétrons, ESI-MS, e técnicas de dissociação induzidas por colisão. Medidas de voltametria cíclica e de espectroeletroquímica foram realizadas para caracterizar os estados redox da porfirina central e dos complexos periféricos, mostrando uma semelhança entre as duas formas isômeras. A maior diferença, entretanto, foi observada nas suas propriedades estruturais, diagnosticadas por modelagem molecular, e refletidas na morfologia dos filmes obtida por meio de técnicas de microscopia de varredura por sonda, SPM, e através da associação com filmes de DNA, monitorada com o auxílio de técnicas de espectroscopia eletrônica e ressonância plasmônica de superfície, SPR. No último caso, o DNA foi imobilizado sobre a superfície do sensor de ouro, usando aminotióis adequados, sendo que a interação do isômero meta conduziu a uma resposta contrastante, relevando uma forte ligação com a cadeia do DNA, provavelmente nas proximidades das fendas estruturais menores desse biopolímero. A interação do isômero para com o DNA foi demasiadamente fraca para ser observada por meio de SPR. A associação molecular das porfirinas tetraplatinadas catiônicas com ftalocianinas aniônicas tetrassulfonadas conduziu à formação de pares iônicos em solução. O filme do isômero para imobilizado sobre eletrodo de carbono vítreo apresentou atividade na redução eletrocatalítica de nitrito. Os trabalhos realizados demonstraram que os novos sistemas supramoleculares derivados de porfirinas e complexos de platina proporcionam interessantes materiais híbridos inorgânico-biológicos contendo DNA e metais nobres, com potenciais aplicações em terapia fotodinâmica, sensoriamento e em dispositivos moleculares. / The synthesis, characterization and investigation of the molecular and supramolecular behaviour of meso-tetrapyridylporphyrins containing four chloro(bipyridine) platinum(II) complexes attached at the meta and para positions of the peripheral pyridine ligands is focused on this thesis. The isomeric supermolecules were isolated in the solid state, and extensively characterized by means of UV-visible, FT-IR and 195Pt NMR spectroscopy, as well as, by TGA and electrospray spectrometry associated with collision induced techniques. Cyclic voltammetry and spectroelectrochemical measurements were performed to characterize the redox sites on the porphyrin and peripheral complexes, revealing a close similarity between the two isomeric supermolecules. Major differences were observed on their structural properties, as demonstrated by means of molecular simulations, and by the morphology of the molecular films probed by SPM techniques, and also by their association with DNA films, which was monitored by means of SPR techniques. In the last case, DNA was first immobilized onto the surface of the gold sensor, using suitable aminothiols and the interaction of the meta-isomer led to a contrasting response, exhibiting a strong binding to the DNA chain, presumably at the proximity of the minor grooves. The interaction of the para-isomer with DNA was too weak to be probed by means of the SPR technique. Molecular association of the tetraplatinum porphyrin species, with tetrasulphonated phtalocyanines, leading to ion pairs in solution, was also investigated. The molecular film of the para-isomer immobilized over glass carbon electrode has shown activity in the electrocatalytic reduction of nitrite. This work on the supramolecular porphyrin platinum species provided new interesting approaches for generating hybrid biological-inorganic systems, containing DNA and noble metals, for sensing applications, and molecular devices.

Submitted by Renata Lopes (renatasil82@gmail.com) on 2017-05-15T14:18:18Z No. of bitstreams: 1 nathaliamagalhaespaixao.pdf: 3549646 bytes, checksum: dfd913fd20520fb3cbfe42b45a3b6f5f (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-05-17T15:59:23Z (GMT) No. of bitstreams: 1 nathaliamagalhaespaixao.pdf: 3549646 bytes, checksum: dfd913fd20520fb3cbfe42b45a3b6f5f (MD5) / Made available in DSpace on 2017-05-17T15:59:23Z (GMT). No. of bitstreams: 1 nathaliamagalhaespaixao.pdf: 3549646 bytes, checksum: dfd913fd20520fb3cbfe42b45a3b6f5f (MD5) Previous issue date: 2017-02-20 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Câncer é um processo de crescimento e disseminação incontrolado de células e tem sido considerado como uma questão de saúde pública. Os compostos polinucleares de Platina (II) têm se mostrado muito promissores contra células cancerosas devido a interações mais rápidas e efetivas em comparação com os compostos mononucleares, como por exemplo, o complexo BBR3464. A partir disso, diversos estudos vêm sendo realizados com intuito de descrever os modos de interação de tais compostos. Este trabalho tem como objetivo fornecer um estudo teórico sistemático do complexo trinuclear de platina (II), AH78, através do uso de diferentes níveis de cálculo. Os compostos trinucleares de platina (II) estudados nesse trabalho não são capazes de formar ligações covalentes com o DNA, interagindo através da formação de grampos de fosfato, que são preferencialmente interações de hidrogênio e eletrostáticas. Dessa forma, este trabalho teve como motivação avaliar a interação dos complexos trinucleares de platina (II) não covalentes com o DNA por meio da formação de grampos de fosfato, analisadas através de modelos miméticos demonstrando presença de tais interações a partir de uma análise mais rápida e eficaz. Foram obtidas estruturas contendo uma fração de DNA que contém 6 pares de bases nitrogenadas e o complexo AH78, utilizando o método ONIOM, que comprovam a existência dos grampos de fosfato entre o complexo e o DNA. / Cancer is a process of uncontrolled growth and spread of cells and has now been considered a public health issue. Polynuclear Platinum (II) Complexes (PPCs) have shown very promising against cancer cells because of faster and more effective interactions compared to mononuclear compounds, such as the BBR3464 complex. From this, several studies have been carried out to describe the modes of interaction of such compounds. This work provides an extensive and systematic theoretical study of the platinum (II) trinuclear complex, AH78, using different base set functions for C, N and H atoms, including diffusive and polarization functions and different ECPs for platinum. The platinum (II) trinuclear compounds studied in this work are not able to form covalent bonds with DNA, interacting by the formation of phosphate bonds, which are preferably hydrogen type and electrostatic interactions. Thus, this work had the motivation to evaluate the interaction of non-covalent platinum (II) trinuclear complexes with DNA by means of the formation of phosphate clamps, analyzed using mimetic models, demonstrating that the presence of such interactions from a faster analysis is efficient. Structures containing a DNA fraction were obtained with six purine base pairs and AH78 complex using the ONIOM method, which demonstrate the existence of the phosphate clamps between the complex and the DNA.

Le travail décrit dans cette thèse se concentre sur le développement de matériaux « durs et mous » ainsi que leur interaction avec les cellules biologiques pour une application finale dans le domaine de la théranostique couvrant l'imagerie, la détection, la thérapie génique et la thérapie du cancer. Dans ce contexte, nous avons tout d'abord étudié l'utilisation de complexes (II) de platine phosphorescents auto-assemblés comme sonde cellulaire. Nous avons étendu l'idée de bio-imagerie en introduisant un concept d’imagerie basée sur l’émission stimulée où nous étions en mesure de générer un laser provenant d'une cellule biologique unique sans utiliser de cavité optique conventionnelle. En outre, des nano-transporteurs multifonctionnels à base de matières poreuses dures à savoir des zéolithes L et des nanoparticules de silice mésoporeuse pour de la « drug delivery » (relargage de médicaments et d’oligonucléotides) in vitro ide ont été développés avec succès et testés pour le traitement du glioblastome. Un autre nano-vecteur, qui est construit à partir de silice biodégradable, a également été synthétisé et sa capacité d'encapsuler des protéines et de les libérer dans les cellules vivantes lors de la dégradation de la structure dans un environnement réducteur a été démontrée. Enfin, l'utilisation de nouveaux matériaux plasmonique sur la base de nanoparticules d'argent enrobées de silice cassable pour la détection d'agents réducteurs a été mise en valeur. / The work described in this thesis focuses on the development of soft- and hard-materials as well as their interaction with biological cells for applications in the field of theranostics covering imaging, sensing, and gene, and cancer therapy. In this context, we first investigated the use of phosphorescent self-assembled platinum(II) complexes as cellular probes. We extended the concept stimulated emission-based bioimaging by generating a laser-like emission coming from a single biological cell without using any conventional optical cavity. In addition, we successfully developed multifunctional nanocarriers based on porous hard materials, namely zeolites-L and mesoporous silica nanoparticles for drug and oligonucleotide delivery in vitro and they were tested to treat glioblastoma. Another nanovector, which is constructed from biodegradable silica, was also synthesized and its ability to encapsulate proteins and release them in living cells upon degradation of the structure in reductive environment was demonstrated. Finally, the use of novel plasmonic structures based on breakable silica-coated silver nanoparticles for detection of reducing agents was successfully investigated.

Les interactions entre des complexes de platine (II) ou de palladium (II) ont une grande influence sur une grande gamme de propriétés chimiques et physiques. Ces propriétés peuvent être étudiées par plusieurs méthodes spectroscopiques comme la spectroscopie Raman, d’absorption, d’émission et de réflectivité diffuse. L’empilement de molécules a un effet important sur les propriétés spectroscopiques de plusieurs composés des éléments de transition. La spectroscopie est très utile pour comprendre les effets intermoléculaires majeurs de plusieurs composés inorganiques. Les complexes plan-carré de platine(II) et de palladium(II) sont très intéressants à cause de leur grande quantité d’effets intermoléculaires et intramoléculaires. Des mesures avec des variations de pression (entre 1 bar et 40 kbar) et de température (entre 80 K et 300 K) ont été effectuées sur ces complexes. La structure à l’état fondamental des composés de platine(II) et de palladium(II) a un effet important sur la spectroscopie de luminescence. Des complexes avec des donneurs axiaux mènent à un effet de déplacement du maximum d’émission vers de plus basses énergies avec l’augmentation de pression. Des complexes similaires sans composante axiale ont un maximum d’émission qui se déplace vers des plus hautes énergies. Ces effets sont explorés à l’aide de plusieurs composés incluant une série de complexes pinceur qui ont démontré des déplacements entre -1 cm-1/kbar et -30 cm-1/kbar. Le changement du type d’émission causé par un changement de pression ou de température est aussi observable. Un complexe de platine(II) montre un changement d’une transition centrée sur le ligand à pression ambiante à une transition de type transfert de charge à plus haute pression. La combinaison de l’information cristallographique et spectroscopique donne de l’information quantitative sur les variations de la structure et des niveaux électroniques de plusieurs complexes. / Interactions between platinum(II) or palladium (II) compounds influence a large range of chemical and materials properties. These properties can be studied with the help of many different spectroscopic methods such as Raman, absorption, luminescence and diffuse reflectance. The stacking of molecules has a very important effect on their photophysical properties. Luminescence spectroscopy is especially useful to understand what role of intermolecular effects in inorganic complexes. Square planar Pt(II) and Pd(II) complexes are very interesting to study because of their multiple intermolecular and intramolecular effects. Work on these complexes under variable external pressure and temperature corresponding to variable intermolecular effects was executed. These changes include variations of pressure (between ambient pressure and 40 kbar) and temperature (from 80 K to 300 K). The ground-state structure of Pt(II) and Pd(II) square planar complexes has an obvious impact on the luminescence properties. Pressure allows a continuous variation of the structure. Complexes with axial donors show a shift of the luminescence maxima to lower energy as pressure increases, similar complexes without the axial component show a shift of the luminescence maxima to higher energy. The packing also plays an important role defining effects of pressure and temperature. These effects are illustrated with a series of pincer complexes that have shown energy shifts between -1 cm-1/kbar and -30 cm-1/kbar. These complexes also show different emitting states depending on the pressure that is applied. A ligand centered (LC) transition is observed at low pressure replaced by a metal-ligand charge transfer (MLCT) emission at higher pressure. The combination of crystallographic and spectroscopic data gives quantitative variations of the electronic structure for many complexes.

Les interactions entre des complexes de platine (II) ou de palladium (II) ont une grande influence sur une grande gamme de propriétés chimiques et physiques. Ces propriétés peuvent être étudiées par plusieurs méthodes spectroscopiques comme la spectroscopie Raman, d’absorption, d’émission et de réflectivité diffuse. L’empilement de molécules a un effet important sur les propriétés spectroscopiques de plusieurs composés des éléments de transition. La spectroscopie est très utile pour comprendre les effets intermoléculaires majeurs de plusieurs composés inorganiques. Les complexes plan-carré de platine(II) et de palladium(II) sont très intéressants à cause de leur grande quantité d’effets intermoléculaires et intramoléculaires. Des mesures avec des variations de pression (entre 1 bar et 40 kbar) et de température (entre 80 K et 300 K) ont été effectuées sur ces complexes. La structure à l’état fondamental des composés de platine(II) et de palladium(II) a un effet important sur la spectroscopie de luminescence. Des complexes avec des donneurs axiaux mènent à un effet de déplacement du maximum d’émission vers de plus basses énergies avec l’augmentation de pression. Des complexes similaires sans composante axiale ont un maximum d’émission qui se déplace vers des plus hautes énergies. Ces effets sont explorés à l’aide de plusieurs composés incluant une série de complexes pinceur qui ont démontré des déplacements entre -1 cm-1/kbar et -30 cm-1/kbar. Le changement du type d’émission causé par un changement de pression ou de température est aussi observable. Un complexe de platine(II) montre un changement d’une transition centrée sur le ligand à pression ambiante à une transition de type transfert de charge à plus haute pression. La combinaison de l’information cristallographique et spectroscopique donne de l’information quantitative sur les variations de la structure et des niveaux électroniques de plusieurs complexes. / Interactions between platinum(II) or palladium (II) compounds influence a large range of chemical and materials properties. These properties can be studied with the help of many different spectroscopic methods such as Raman, absorption, luminescence and diffuse reflectance. The stacking of molecules has a very important effect on their photophysical properties. Luminescence spectroscopy is especially useful to understand what role of intermolecular effects in inorganic complexes. Square planar Pt(II) and Pd(II) complexes are very interesting to study because of their multiple intermolecular and intramolecular effects. Work on these complexes under variable external pressure and temperature corresponding to variable intermolecular effects was executed. These changes include variations of pressure (between ambient pressure and 40 kbar) and temperature (from 80 K to 300 K). The ground-state structure of Pt(II) and Pd(II) square planar complexes has an obvious impact on the luminescence properties. Pressure allows a continuous variation of the structure. Complexes with axial donors show a shift of the luminescence maxima to lower energy as pressure increases, similar complexes without the axial component show a shift of the luminescence maxima to higher energy. The packing also plays an important role defining effects of pressure and temperature. These effects are illustrated with a series of pincer complexes that have shown energy shifts between -1 cm-1/kbar and -30 cm-1/kbar. These complexes also show different emitting states depending on the pressure that is applied. A ligand centered (LC) transition is observed at low pressure replaced by a metal-ligand charge transfer (MLCT) emission at higher pressure. The combination of crystallographic and spectroscopic data gives quantitative variations of the electronic structure for many complexes.

Im ersten Teil der Arbeit wird die Synthese neopentyl- und neosilylsubstituierter Phosphane zur Verwendung als Liganden in katalytisch aktiven Palladiumkomplexen beschrieben. Die Aktivität wurde in der Suzuki-Miyaura Kreuzkupplungsreaktion getestet. Während die neosilylsubstituierten Phosphane 2:1 Addukte (5b und 5d) mit geeigneten Palladiumsalzen bilden, welche moderate Katalyseaktivität zeigen, untergehen die neopentylsubstituierten Komplexe schnelle Cyclometalierungsreaktionen in Gegenwart von Basen und bilden die katalytisch wenig aktiven Palladacyclen (6a, 6e, and 6g). Die deaktivierende Cylometallierung konnte durch Darstellung der Palladiumcomplexe ausgehend von Pd(cod)Cl2 in Abwesenheit von Basen vermieden werden. Die erhaltenen 2:1 Phosphaneaddukte zeigten deutlich verbesserte Aktivität. Daraus wurde geschlossen, dass die Cyclomettalierung als Nebenreaktion eine wichtige Deaktiverungsmöglichkeit darstellt, diese Überlegung veranlasste uns Trialkylphosphane mittlerer Größe, mit Substituenten die nur schwer eine Cyclometallierungen eingehen können zu testen. Die Verwendung der Phosphoniumsalze 4h (R = Cy, R‘ = neopentyl) und 4m (R = iPr, R‘ = CH2Cy) führt zu höheren Aktivitäten in der Suzuki-Miyaura Kreuzkupplung, als bestes Katalysatorsystem hat sich die Kombination aus Pd2(dba)3 oder Pd(OAc)2 und entsprechendem Phosphoniumsalz ergeben. Im zweiten Teil dieser Arbeit werden Synthesen zu neuen biphenylbasierten Diphosphanen (70, 71, 76, and 77) vorgestellt. Die Palladiumkomplexe wurden ebenfalls auf ihre Eignung als Katalysatoren in palladiumkatalysierten Suzuki-Miyaura Kreuzkupplungen getestet und zeigen für diese Klasse von Komplexen gute Aktivität. Das Tetraphosphan 82 wurde für die Synthese des zweikernigen Palladium(II)-komplex 83 eingesetzt. Durch die Koordination des D2h-symmetrischen Tetraphosphanes an die Palladiumatome wird die Symmetrie des Moleküls erniedrigt und folglich erhält man den formal D2-symmetrischen Komplex 83. / In the first part of this thesis, the synthesis and catalytic activity of neopentyl and neosilyl substituted phosphine palladium complexes is described. The complexes have been tested in the Suzuki-Miyaura cross-coupling reaction. Whereas the neosilyl substituted phosphines form 2:1 adducts (5b and 5d) with Palladium salts which showed moderate activity, the neopentyl complexes quickly undergo cyclometallation in presence of bases to form Palladacycles (6a, 6e, and 6g) which showed only moderate catalytic activity. Cyclometallation could be avoided by the preparation starting from Pd(cod)Cl2 in the absence of bases. The obtained 2:1 phosphine adducts showed superior activity. We concluded that cyclometallation process is an important deactivation pathway, this prompted us to test trialkyl phosphine ligands with medium size but substituents not reliable to cyclometallation. We have been pleased to find that 4h (R = Cy, R‘ = neopentyl) and 4m (R = iPr, R‘ = CH2Cy) showed good activity in the Suzuki-Miyaura cross-coupling reaction. The best results have been obtained by in situ preparation of active catalyst from Pd2(dba)3 or Pd(OAc)2 and the appropriate phosphonium salt. In the second part of this thesis, the first synthesis of a new family of biphenyl based bisphosphine ligands (70, 71, 76, and 77) has been reported. Their palladium complexes were successfully tested as catalyst in the Suzuki cross-coupling reaction. Within the class of bisphosphine based palladium complexes they show good activity in Suzuki-Miyaura cross-coupling reaction. Systematically, was expanded our synthesis strategy and we were able to introduce the first synthesis of a highly symmetric 2,2',6,6'-tetraphosphinobiphenyl. Tetraphosphine 82 was used as ligand in a dinuclear palladium(II) complex 83. Upon complexation the D2h symmetric 2,2’,6,6’-tetraphosphine lead to a chiral D2 symmetric complex 83.

Made available in DSpace on 2014-07-29T15:12:45Z (GMT). No. of bitstreams: 1 Dissertacao Rubiane Marta Mayer Ferreira.pdf: 3757686 bytes, checksum: 18a8d13079b5ee2dd0758b888c456397 (MD5) Previous issue date: 2011-08-26 / NOTE: As programs do not copy or copy errors with certain symbols, formulas, formatting ... etc, to view the summary and the entire file, click PDF - dissertation at the bottom of the screen. / OBS: Como programas não copiam ou copiam com erros certos símbolos, fórmulas, formatações... etc, para visualizar o resumo e todo o arquivo, click em PDF - dissertação na parte de baixo da tela.

Ferrocene is an important molecule in the field of chemical biology due to its stability, unique redox property and significant lipophilicity for better cellular delivery. The medicinal importance of ferrocene is well recognized after its successful incorporation into breast cancer drug tamoxifen and antimalarial drug chloroquin. Designing ferrocene conjugated transition metal complexes is an interesting area of research in the field of photodynamic therapy, a new modality of light activated cancer treatment. The objective of the present thesis work is to develop photoactive ferrocene conjugates showing DNA photocleavage and photocytotoxic activity. We have synthesized the ferrocene conjugated imidazophenanthroline derivative which exhibits visible light induced DNA photocleavage activity and photocytotoxicity in HeLa cell line. The corresponding phenyl analogue is found to be inactive. Polypyridyl platinum(II) complexes of ferrocenyl as well as phenyl moiety are prepared and studied their interactions with calf thymus DNA. The cytotoxicity of the complexes enhance significantly upon irradiation of UV-A light of 365 nm. To enhance the photodynamic potential and to understand the role of organometallic ferrocenyl moiety, ferrocene conjugated terpyridyl copper(II) complexes having planar phenanthroline bases are prepared. The interaction of these complexes with duplex DNA and their photo-induced DNA cleavage and anticancer activity in HeLa cancer cells are studied. The complexes are able to generate ROS in the presence of visible light which causes DNA damage as well as cell death. The importance of ferrocenyl moiety is evidenced from the less activity of the corresponding phenyl analogues complex. We have prepared copper(II) complexes of ferrocenyl methyl dipicolylamine ligand to understand the role of terpyridyl moiety. These complexes lacking any conjugation between the copper(II) and the ferrocenyl moiety are found to be less active compared to the terpyridyl conjugated system. The copper(II) complexes are found to show undesirable dark cytotoxicity in the presence of cellular thiols like GSH. To overcome the dark toxicity problem and to understand the mechanistic aspects of DNA photocleavage and photocytotoxicity, a series of binary ferrocene conjugated terpyridyl complexes of Fe(II), Co(II), Cu(II) and Zn(II) are prepared and their DNA photocleavage and anticancer activity studied. The zinc(II) complex having redox-active ferrocenyl moiety and redox-inactive zinc(II) center exhibits significant PDT effect with low dark toxicity compared to its copper(II) analogue. The ferrocenyl moiety plays an important role towards showing photocytotoxic activity since its phenyl analogue is inactive in nature. Finally, the present thesis work opens up a new strategy for designing and developing new ferrocene based metal complexes as novel photosensitizers for PDT applications.