O presente trabalho apresenta estudos espectrofotométricos relacionados à autoxidação dos complexos de Cu(II), Ni(II) e Co(II)/tetraglicina induzida por sulfito. Nossos estudos verificaram que a autoxidação de Cu(II)/tetraglicina (1,0x10-3 mol L-1) em pH = 9,0 (tampão borato) é afetada pela presença de traços de Ni(II) ou Co(II). Na ausência de Ni(II) ou Co(II), a reação é muito ineficiente e lenta com períodos de indução longos (aproximadamente 4 h). Ni(II) ou Co( II) em concentrações baixas ( 10-5 - 10-6 mol L-1) afetam significativamente a cinética: o período de indução diminui drasticamente (a menos de 2 s) e a formação de Cu(III) é fortemente acelerada com simultâneo aumento da eficiência da reação. A atividade catalítica e o sinergismo positivo de Co(II) e Ni(II) podem ser explicados pela oxidação mais rápida de Co(II) ou Ni(II)/tetraglicina pelo oxigênio dissolvido. O processo eletroquímico relacionado aos sistemas Cu(II)/Cu(III)/tetraglicina e Ni(II)/Ni(III)/tetraglicina são reversíveis, possibilitando monitorá-los adequadamente mediante o uso da técnica de eletrodo rotativo disco-anel. Entretanto, o sistema Co(II)/Co(III)/tetraglicina é irreversível. Esses estudos mostraram que as espécies de Cu(III) e Ni(III) geradas no eletrodo disco são instáveis nas condições experimentais empregadas. O efeito sinérgico positivo na presença de Ni(II) (que permitiu aumentar a sensibilidade) foi aproveitado para desenvolvimento de método espectrofotométrico e amperométrico simples e sensível para a determinação indireta de sulfito em meio aquoso. O método espectrofotométrico está baseado na medida de absorbância do complexo de Cu(III)/tetraglicina (gerado na presença de sulfito e traços de Ni(II)) em 365 nm. O método amperométrico em análise por injeção em fluxo baseia-se na medida de corrente (0,1 V vs Ag/AgCl) em função da concentração de Cu(III)/tetraglicina gerado quimicamente, na presença de sulfito e traços de Ni(II). Os métodos desenvolvidos foram empregados para a determinação de S(IV), em vinhos e sucos, após a sua extração da amostra acidificada, os resultados obtidos concordaram com aqueles obtidos pelo método iodométrico. / The present work presents spectrophotometric studies related to the sulfite induced autoxidation of Cu(II), Ni(II) and Co(II)/tetraglycine complexes. The sulfite induced autoxidação of Cu(II)/tetraglycine (1.0x10-3 mol L-1) at pH = 9.0 (borate buffer) is affected by the presence of small quantities of the Ni(II) or Co(II). In the absence of added nickel (II) or cobalt (II), the reaction is very inefficient and slow with one large induction period (about 4 h). Trace amounts of Ni(II) or Co(II) (10-5 - 10-6 M) affect the kinetic significantly: the induction period drastically decreases (less than 2 s) and the formation of Cu(III) is strongly accelerated. The effectiveness of Cu(III) formation becomes much higher. The catalytic activity and the positive synergism of Co(II) and Ni(II) may be explained by the faster oxidation of Co(II) or Ni(II)/tetraglycine complexes by dissolved oxygen. The electrochemistry of Cu(II)/Cu(III)/tetraglycine and Ni(II)/Ni(III)/tetraglycine systems are reversible, such as it was possible to monitor them by using the rotating ring-disk electrode technique. However, the Co(II)/Co(III)/tetraglycine system is irreversible. Those studies showed that the Cu(III) and Ni(III) species generated on the disk electrode are unstable in the employed experimental conditions. The positive sinergistic effect in the presence of Ni(II) (which allowed to increase the sensibility) was taken in advantage for development of one simple and sensitive spectrophotometric and amperometric method for indirect determination of sulfite in aqueous medium. The spectrophotometric method is based on the absorbance measurement of the Cu(III)/tetraglicyne complex (generated in the presence of sulfite and small quantities of Ni(II)) at 365 nm. The amperometric method by flow injection analysis is based on the current measurement (0.1 V vs Ag/AgCl) as function of Cu(III)/tetraglycine concentration chemically generated, in the presence of sulfite and Ni(II). The methods were employed for the determination of S(IV), in wines and juices, after its extraction from acidified samples and the results were in agreement with those obtained by the iodometric procedure.

Šiame eksperimente buvo nagrinėjama pH įtaka Cr (VI) ir Cu (II) jonų pašalinimui iš vandeninių tirpalų, naudojant metalinę geležį Fe (0), kai tirpalų pH vertės buvo nuo 2 iki 6, purtymo procese, uždaruose ir atviruose induose. Kadangi Cr (VI) ir Cu (II) jonų koncentracijų sumažėjimas tirpale priklauso nuo geležies paviršiaus, tai labai svarbu ją tinkamai paruošti: išvalyti ir aktyvuoti. Maksimalus Cr (VI) jonų pašalinimo efektyvumas buvo esant pH vertei 2, o Cu (II) jonų atveju, kai pH vertė 4 uždaruose induose ir atviruose induose – chromo atveju pH 6, vario atveju, kai pH 4. Pašalinimo įvertinimui naudojamos kalibraciniės kreivės pagal kurias apskaičiuojamos likusiųjų jonų koncentracijos, matuojant tirpalų optinius tankius. Metodas yra pigus ir patikimas, nes pašalinima didelė dalis sunkiųjų metalų jonų. / The effects of pH on Cr (VI) and Cu (II) ions removal from solutions by Fe (0) was investigated by batch shaking process. Since the presence of ferrous iron in the solution is mainly responsible for Cr (VI) and Cu (II) reduction the surface of iron must be purified and activated. The maximum Cr (VI) removal efficiency was found at pH 2 and in Cu (II) case it was pH 4 without oxygen and in case with open jar it was for Cr (vi) removal pH 6 and for Cu (II) removal pH 4. Remained concentrations of Cu (II) and Cr (VI) ions were investigated using calibrated graphs and analysis of optical density. This study confirmed that this method is cheap because we can use wasted iron and effective of removing most of heavy metal ions from solutions.

Triazenido ions are isoelectronic to amidinato anions,[R'N C(R)=NR']- and have a broad versatility in coordination chemistry. Metal complexes including triazenido ligands find applications in various areas of chemistry. Triazenes and complexes including triazole derivatives show extensive applicability as for example in supramolecular chemistry and pharmacological compounds. This work presents deals with the study of new triazene derivatives with triazole substituents resulting from the click reactions, acting as ligands in complexes with Cu(I), Cu(II) and Au(I). The following ligands 1,3-bis(2-azidophenyl)triazene (2), 1-(methyl)-3-(2-(4-phenyl-1,2,3-triazole)triazene-N-oxide (4), 1-(phenyl)-3-(2-(4-phenyl-1,2,3-triazole)triazene (5), 1,3-bis(2-(4-phenyl-1,2,3-triazole)triazene (6) and, complexes 1,3-bis(2-azidophenyl)triazenide-κN11- triphenylphosphine-gold(I) (2a), bis-{1-(methyl)-3-[2-(4-phenyl-1,2,3-triazole-κN2)]triazenide-1-oxide-κ2N3,O}copper(II) (4b), 1-(phenyl)-3-(2-(4-phenyl-1,2,3-triazole)triazenide-κN- triphenylphosphine-κP-gold(I) (5a), 1,3-bis(2-(4-phenyl-1,2,3-triazole)triazenide-κN- triphenylphosphine-κP-gold(I) (6a), bis[1,3-bis(2-(4-phenyl-1,2,3-triazole-κN2)-μ-N3-triazenide]-κN11,κN13 copper(I)κN13,κN11´copper(I) (Cu Cu) (6b) were investigated. The compounds were characterized by IR, UV-Vis and NMR (1H e 13C) spectroscopy, low or high resolution mass spectrometry (EI, ESI, ESI(+)-TOF and ESI(-)-TOF) and X-ray diffraction on single crystal. Triazene (2) and complex (2a) exhibit intramolecular assembling through classical and non-classical hydrogen bonding. Complexes with Au(I), (2a), (5a) e (6a), the metal atom show linear coordination geometry. The metal atom in complex (6b) shows a T distorted coordination geometry, which is extended to a quadratic coordination resulting from d10 d10 interactions between Cu(I) ions. Triazene (6) and its respective complexes (6a) e (6b) exhibit intermolecular interactions of the type C−H···M. Antibacterial activity of triazene (5) and complex (5a) were assayed resulting to be inactive against the bacteria tested. / Os compostos triazenidos são isoeletrônicos a íons amidinatos [R'NH C(R)=NR'], e têm sido usados com sucesso na química de coordenação. A complexação a íons metálicos possibilita a sua aplicação em diversas áreas da química. Assim como os triazenos, os triazóis possuem vasta aplicabilidade, desde a química supramolecular até a área farmacológica. Este trabalho apresenta o estudo inédito de pré-ligantes triazenos contendo substituintes triazóis os quais foram obtidos a partir de reações de Click, e seus respectivos complexos de Cu(I), Cu(II) e Au(I). Foram sintetizados os pré-ligantes 1,3-bis(2-azidofenil)triazeno (2), 1-(metil)-3-(2-(4-fenil-1,2,3-triazol)triazeno-N-óxido (4), 1-(fenil)-3-(2-(4-fenil-1,2,3-triazol)triazeno (5), 1,3-bis(2-(4-fenil-1,2,3-triazol)triazeno (6) e os complexos 1,3-bis(2-azidofenil)triazenido-κN11-trifenilfosfina-ouro(I) (2a), bis-{1-(metil)-3-[2-(4-fenil-1,2,3-triazol-κN2)]triazenido-1-óxido-κ2N3,O}cobre(II) (4b), 1-(fenil)-3-(2-(4-fenil-1,2,3-triazol)triazenido-κN-trifenilfosfina-κP-ouro(I) (5a), 1,3-bis(2-(4-fenil-1,2,3-triazol)triazenido-κN-trifenilfosfina-κP-ouro(I) (6a), bis[1,3-bis(2-(4-fenil-1,2,3-triazol-κN2)-μ-N3-triazenido]-κN11,κN13 - cobre(I)κN13,κN11´cobre(I) (Cu Cu) (6b). Estes foram caracterizados por espectroscopia de IV, UV-Vis e RMN (1H e 13C), espectrometria de massas de baixa ou alta resolução (EI, ESI, ESI(+)-TOF e ESI(-)-TOF) e difração de raios X em monocristal. O triazeno (2) e complexo (2a) apresentam ligações de hidrogênio intermoleculares e intramoleculares do tipo clássica e não-clássica. Os complexos de Au(I), (2a), (5a) e (6a) possuem geometria de coordenação linear. O complexo (6b) apresenta uma geometria T distorcida, a qual é estendida para quadrática pela interação d10 d10 entre os átomos de Cu(I), o triazeno (6) e seus complexos (6a) e (6b) apresentam ainda ligações intermoleculares do tipo C−H···M. Foi testada a atividade antibacteriana do triazeno (5) e o complexo (5a), os quais mostraram-se inativos frente às bactérias testadas.

O presente trabalho apresenta estudos espectrofotométricos relacionados à autoxidação dos complexos de Cu(II), Ni(II) e Co(II)/tetraglicina induzida por sulfito. Nossos estudos verificaram que a autoxidação de Cu(II)/tetraglicina (1,0x10-3 mol L-1) em pH = 9,0 (tampão borato) é afetada pela presença de traços de Ni(II) ou Co(II). Na ausência de Ni(II) ou Co(II), a reação é muito ineficiente e lenta com períodos de indução longos (aproximadamente 4 h). Ni(II) ou Co( II) em concentrações baixas ( 10-5 - 10-6 mol L-1) afetam significativamente a cinética: o período de indução diminui drasticamente (a menos de 2 s) e a formação de Cu(III) é fortemente acelerada com simultâneo aumento da eficiência da reação. A atividade catalítica e o sinergismo positivo de Co(II) e Ni(II) podem ser explicados pela oxidação mais rápida de Co(II) ou Ni(II)/tetraglicina pelo oxigênio dissolvido. O processo eletroquímico relacionado aos sistemas Cu(II)/Cu(III)/tetraglicina e Ni(II)/Ni(III)/tetraglicina são reversíveis, possibilitando monitorá-los adequadamente mediante o uso da técnica de eletrodo rotativo disco-anel. Entretanto, o sistema Co(II)/Co(III)/tetraglicina é irreversível. Esses estudos mostraram que as espécies de Cu(III) e Ni(III) geradas no eletrodo disco são instáveis nas condições experimentais empregadas. O efeito sinérgico positivo na presença de Ni(II) (que permitiu aumentar a sensibilidade) foi aproveitado para desenvolvimento de método espectrofotométrico e amperométrico simples e sensível para a determinação indireta de sulfito em meio aquoso. O método espectrofotométrico está baseado na medida de absorbância do complexo de Cu(III)/tetraglicina (gerado na presença de sulfito e traços de Ni(II)) em 365 nm. O método amperométrico em análise por injeção em fluxo baseia-se na medida de corrente (0,1 V vs Ag/AgCl) em função da concentração de Cu(III)/tetraglicina gerado quimicamente, na presença de sulfito e traços de Ni(II). Os métodos desenvolvidos foram empregados para a determinação de S(IV), em vinhos e sucos, após a sua extração da amostra acidificada, os resultados obtidos concordaram com aqueles obtidos pelo método iodométrico. / The present work presents spectrophotometric studies related to the sulfite induced autoxidation of Cu(II), Ni(II) and Co(II)/tetraglycine complexes. The sulfite induced autoxidação of Cu(II)/tetraglycine (1.0x10-3 mol L-1) at pH = 9.0 (borate buffer) is affected by the presence of small quantities of the Ni(II) or Co(II). In the absence of added nickel (II) or cobalt (II), the reaction is very inefficient and slow with one large induction period (about 4 h). Trace amounts of Ni(II) or Co(II) (10-5 - 10-6 M) affect the kinetic significantly: the induction period drastically decreases (less than 2 s) and the formation of Cu(III) is strongly accelerated. The effectiveness of Cu(III) formation becomes much higher. The catalytic activity and the positive synergism of Co(II) and Ni(II) may be explained by the faster oxidation of Co(II) or Ni(II)/tetraglycine complexes by dissolved oxygen. The electrochemistry of Cu(II)/Cu(III)/tetraglycine and Ni(II)/Ni(III)/tetraglycine systems are reversible, such as it was possible to monitor them by using the rotating ring-disk electrode technique. However, the Co(II)/Co(III)/tetraglycine system is irreversible. Those studies showed that the Cu(III) and Ni(III) species generated on the disk electrode are unstable in the employed experimental conditions. The positive sinergistic effect in the presence of Ni(II) (which allowed to increase the sensibility) was taken in advantage for development of one simple and sensitive spectrophotometric and amperometric method for indirect determination of sulfite in aqueous medium. The spectrophotometric method is based on the absorbance measurement of the Cu(III)/tetraglicyne complex (generated in the presence of sulfite and small quantities of Ni(II)) at 365 nm. The amperometric method by flow injection analysis is based on the current measurement (0.1 V vs Ag/AgCl) as function of Cu(III)/tetraglycine concentration chemically generated, in the presence of sulfite and Ni(II). The methods were employed for the determination of S(IV), in wines and juices, after its extraction from acidified samples and the results were in agreement with those obtained by the iodometric procedure.

Submitted by Fernanda Stuani Pereira null (ferstuani@hotmail.com) on 2016-06-22T22:22:49Z No. of bitstreams: 1 Tese-FERNANDA STUANI PEREIRA.pdf: 6105856 bytes, checksum: 653cf59956934017da496664aa74e886 (MD5) / Approved for entry into archive by Ana Paula Grisoto (grisotoana@reitoria.unesp.br) on 2016-06-24T17:11:14Z (GMT) No. of bitstreams: 1 pereira_fs_dr_prud.pdf: 6105856 bytes, checksum: 653cf59956934017da496664aa74e886 (MD5) / Made available in DSpace on 2016-06-24T17:11:14Z (GMT). No. of bitstreams: 1 pereira_fs_dr_prud.pdf: 6105856 bytes, checksum: 653cf59956934017da496664aa74e886 (MD5) Previous issue date: 2016-06-09 / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / O presente trabalho descreve modificações estruturais feitas na cadeia lateral do polímero quitosana mediante a N-alquilação com diferentes aldeídos aromáticos, a qual originam bases de Schiff como produtos intermediários, seguido de uma redução com cianoborohidreto de sódio (NaBH3CN). Subsequentemente, reações de acoplamento entre o produto sintetizado N-benzil quitosana e diferentes sais de diazônio foram realizadas para produzir uma nova classe de compostos poli-azóicos a partir deste polímero. Diferentes materiais foram sintetizados para investigar a influencia de diferentes substituintes na complexação de metais e futuros estudos de eficiência biológica. Pela técnica de ressonância magnética nuclear de próton em solução, o grau de substituição dos poli-azo-compostos foi de 46 a 66%. Os compostos foram caracterizados por FT-IR e RMN de 13C no estado sólido e RMN de 15N em solução, que confirmaram a síntese dos derivados poliméricos. Também foi realizado um estudo da interação destes materiais sintetizados com os íons metálicos Cu(II) e Zn(II). Para a caracterização dos complexos, utilizou-se as técnicas de titulação complexométrica, FAAS, MEV, EDS, difratometria de raios X, EPR e TG/DTG. Por titulação complexométrica e FAAS, a quitosana pura mostrou maior capacidade em complexar/adsorver os metais do que seus derivados. A capacidade de adsorver íons Cu(II) foi maior do que íons Zn(II) para todos os compostos. Por MEV e EDS, observou-se que além do cobre coordenado pelos sítios reativos dos materiais, o sal sulfato de cobre foi adsorvido pela superfície polimérica dos mesmos. Assim, foram realizadas reações de complexação utilizando o sal CuCl2.2H2O e os resultados mostraram que esse comportamento não ocorre para este sal. Para os complexos utilizando o sal sulfato de zinco, praticamente não se observa o sal adsorvido na superfície polimérica, devido à baixa capacidade de complexação por esse metal. A difratometria de raios X mostrou uma redução da cristalinidade dos complexos de cobre e zinco formados pela quitosana e o derivado Q1Benzil devido a maior capacidade desses materiais em quelar íons metálicos. Para os complexos de Cu(II) e Zn(II) formados a partir do composto Azo-Anisidina, o índice de cristalinidade aumenta, o que pode estar associado a formação de diferentes ligações de coordenação nesse composto. A formação dos complexos também foi confirmada por espectroscopia Raman. Os espectros de EPR dos complexos de Cu(II) formados a partir do sal CuCl2.2H2O mostram a presença de uma estrutura hiperfina bem resolvida, da mesma forma que foi observado para o complexo Quitosana-CuSO4, na qual a grande maioria dos centros de cobre são monoméricos e provavelmente ligados aos polímeros. As curvas de TG/DTG mostraram que os derivados poliméricos degradam a temperaturas menores que o polímero não modificado, e os complexos com sulfato de cobre apresentaram perfis TG/DTG diferentes dos complexos sintetizados a partir do sal cloreto de cobre. Por fim, tanto a quitosana quanto seus derivados Q1Benzil, Q2Benzil e Q2Benzil utilizando a quitosana de baixo peso molecular se mostraram efetivos na síntese de carbonatos através da captura e fixação de CO2 por estes materiais poliméricos. / The present work describes structural modifications in the side chain of the polymer chitosan by N-alkylation with different aromatic aldehydes, which originates Schiff base as an intermediate, followed by reduction with sodium cyanoborohydride (NaBH3CN). Subsequently, coupling reactions between the synthesized product N-benzyl chitosan and various diazonium salts were carried out to produce a new class of poly-azo compounds from this polymer. Different materials were synthesized to investigate the influence of different substituents on metal chelation and future studies of their biological efficience. From nuclear magnetic resonance technique, the degree of substitution of the poly-azo compounds was between 46 and 66%. The compounds were characterized by FT-IR, 13C NMR in solid state and 15N NMR in solution, which confirmed the synthesis of the polymeric derivatives. The interaction of the synthesized materials with the metal ions Cu(II) and Zn(II) was also studied. For the characterization of such metal complexes, the techniques complexometric titration, FAAS, SEM, EDS, X-ray diffraction, EPR and TG/DTG were employed in this work. By complexometric titration and FAAS, pure chitosan showed greater capacity for complex/adsorb metals than its derivatives. The capacity of adsorbing Cu(II) ions was greater than Zn(II) ions for all compounds. The synthesized complexes were studied by various spectroscopic techniques. By SEM and EDS, it was observed that in addition of copper coordination, copper sulphate salt was adsorbed by the polymer surface. Thus, complexation reactions were carried out using the salt CuCl2.2H2O and the results showed that this behavior does not occur for this salt. For complexes using zinc sulfate salt, hardly observes this salt adsorbed on the polymeric surface due to the low capacity for complexing this metal. The X-ray diffraction showed a reduction of the crystallinity of copper and zinc complexes formed by chitosan and Q1Benzil derivative due to the greater ability of these materials to chelate metal ions. For the complexes of Cu(II) and Zn(II) formed from Azo-Anisidine compound, the crystallinity index increases, which can be associated with formation of different coordination bonds with the compound. The formation of the complex was also confirmed by Raman spectroscopy. EPR spectra of Cu(II) formed from the CuCl2.2H2O salt showed the presence of well resolved hyperfine structure in the same way as it was observed for chitosan-CuSO4, in which the majority of copper centers are monomeric and probably bound to the polymer. The TG/DTG curves showed that polymeric derivatives are less stable than the unmodified polymer, and complexes with copper sulfate had TG/DTG curves different from the complexes synthesized from copper chloride salt. Finally, chitosan and the derivatives Q1Benzil , Q2Benzil and Q2Benzil from low molecular weight chitosan were effective in the synthesis of carbonates through the capture and sequestration of CO2 by these polymeric materials. / FAPESP: 2012/13901-3

De nouveaux matériaux ont été conçus à partir de matériaux hybrides organique-inorganiques mésoporeux renfermant des complexes de Cu(II). Ils ont été mis en œuvre comme catalyseurs dans des réactions d'oxydation sélective. La localisation des sites du métal a été contrôlée en utilisant trois ligands synthétiques le type organosilane et deux stratégies différentes, c. àd.,une synthèse dite "one-pot", et un greffage post-synthètique. Les organosilanes ont été le N-(2-aminoéthyl)-3-aminopropyltriméthoxysilane (L1), le N-propylamine-salicylaldimine-triméthoxy-silane (L2) et le de N-(salicylaldimine)- (N'-propyltriméthoxylsilane)-diéthylènetriamine (L3). En outre, l'ion Ni(II) a été utilisé comme sonde structurale. Selon la synthèse "one-pot", les complexes Ni(II)-L1, Cu(II)-L1 et Cu(II)-L2 ont été co-condensés avec du silicate de sodium en présence d'un tensoactif, le cé-tyltriméthylammonium tosylate. Ce dernier avait le rôle de gabarit structurant pour la cons-truction d'organosilices mésoporeuses périodiques (PMOs), de structure bien ordonnée de type MCM-41. Ces matériaux ont ensuite été soumis à des traitements mis au point pour pré-server la structure mésoporeuse utilisant un mélange de chlorotriméthylsilane et hexaméthyl-disilazane ou une quantité appropriée de HCl aqueux (lavage) pour extraire le tensio-actif. Dans les greffages post synthétiques, les complexes Ni(II)-L1, Cu(II)-L1 ou Cu(II)-L3 ont été liés de façon covalent à la surface de silice mésoporeuse préformée selon une distribution uniforme mettant en œuvre une technique dite de pochoir moléculaire. Une caractérisation multitechnique approfondie fut mener pour vérifier la structure et la morphologie du matériau et pour déterminer le site de coordination du métal (XRD, TEM, isothermes d'adsorp-tion-désorption d'azote, analyse élémentaire, ATG, spectroscopies DRUV, FT-IR et RPE). De plus, l'accessibilité chimique du site métallique et le relargage du métal ont été testés en utili-sant 1) l'isothiocyanate (SCN-) comme ligand sonde, 2) l' échange des ions Ni(II) par les ions Cu (II) d'ions ou encore 3) la résistance à la lixiviation acide. Outre les sites métalliques des canaux obtenus par greffage et trés ressemblant à des sites "en solution", deux autres sites ont été mis en évidence. Ils sont tous les deux situés dans les murs des pores. L'un non accessible, est appelé “site enlisé”, l'autre est “site émergenant”. L'activité catalytique en hydroxylation du phénol par le peroxyde d'hydrogène et oxydation du catéchol par le dioxygène dépend de la localisation du métal. Les complexes Cu(II)-L3 greffés présentent les meilleures activités catalytiques et fonctionnent dans l'eau. La conversion et la sélectivité en produits valorisables comme le catéchol et l'hydroquinone, ont été étudiées en fonction du temps, de la température, du pH et du rapport substrat /oxydant. Enfin, le recyclage du catalyseur a également été étu-dié.

Aquest treball teòric estudia l'acoblament magnètic en complexos bi- i trinuclears heterometàl·lics amb lligands pont oxamido, oxamato, ditiooxalato i anàlegs. Per calcular la seva estructura electrònica s'han usat mètodes multireferencials, en particular diferents variants del mètode DDCI, desenvolupat en el grup, i el mètode CASPT2. Per diferents sistemes binuclears coneguts de Cu(II) i Mn(II), l'acoblament magnètic i els mapes de densitat de spin calculats reprodueixen acuradament les dades experimentals. L'acoblament antiferromagnètic en aquests depèn de la transferència de càrrega del lligand al metall, lligada a l'electronegativitat dels àtoms coordinats. En els sistemes hipotètics de tipus Cu(II)-M(II)-Cu(II), on M=Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu i Zn, la magnitud de l'acoblament estimada depèn de l'electronegativitat del metall central, anant de feblement ferromagnètic pel Sc a moderadament antiferromagnètic pel Cu. Aquest treball aporta la interpretació microscòpica de l'acoblament en aquests sistemes, així com la validació i/o les limitacions dels mètodes de càlcul emprats. / This theoretical work examines the magnetic coupling in bi- and trinuclear heterometallic transition metal complexes with bridging ligands such as oxamido, oxamato, ditiooxalato and analogues. To calculate their electronic structure multireference methods have been used, including different variants of DDCI method, developed in our group, and CASPT2 method. For different Cu(II)-Mn(II) binuclear known systems, the magnetic couplings and spin density maps calculated accurately reproduce the experimental data. The antiferromagnetic coupling in these compounds depends on the charge transfer from ligand to metal, linked to the electronegativity of coordinated atoms. In the hypothetical systems of type Cu(II)-M(II)-Cu(II), where M = Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu and Zn, the magnitude of the estimated coupling depends on the electronegativity of the metal core, going from the weakly ferromagnetic for Sc to moderately antiferromagnetic for Cu. This work provides the microscopic interpretation of the coupling in these systems, as well as the validation and/or limitations of the computational methods used.

Desenvolveu-se um método espectrofotométrico para determinação de íons Cu(II), Fe(II) e Fe(III) com o reagente cromogênico di-2-piridil cetona benzoilhidrazona (DPKBH), em condições estacionárias e em fluxo. Fez-se a caracterização estrutural e estequiométrica do complexo de Cu(II) com DPKBH usando-se técnicas espectroscópicas de infravermelho e massas, além de análise térmica e elementar. Estudou-se, ainda, a estequiometria dos complexos de Fe(II) e Fe(III) com DPKBH utilizando espectrometria de massas com ionização por electrospray. Desenvolveu-se, preliminarmente, um método espectrofotométrico para a determinação de íons Cu(II) com DPKBH e aplicou-se em amostras de aguardente. Posteriormente, adaptou-se para análise por injeção em fluxo, utilizando-se injetor comutador manual. Em seguida, desenvolveu-se em condições estacionárias um método espectrofotométrico para determinação de Fe(II) e Fe(III) e Cu(II) em uma mesma amostra, com o uso de agentes mascarantes. Fez-se também a adaptação do método para análise em fluxo empregando multicomutação e amostragem binária. Finalmente, determinou-se a concentração de íons Cu(II), Fe(II) e Fe(III) em amostras sintéticas e Cu(II) e ferro total em amostras de sedimento coletadas no reservatório de Guarapiranga. Os resultados obtidos foram comparados com o método de referência de ICP-OES, apresentando concordância para um nível de confiança de 95% da média. / A spectrophotometric method was developed to the determination of Cu(II), Fe(II) and Fe(III) with the chromogenic reagent di-2pyridyl ketone benzoylhydrazone (DPKBH) in stationary conditions as a flow injection process. The structural characterization and the stoichiometry of Cu(II)/DPKBH complex were achieved using infrared spectrometry, mass spectrometry, thermal and elementar analysis. Toe stoichiometry of the Fe(II) and Fe(III) complexes with DPKBH was studied by electrospray ionization mass spectrometry. The spectrophotometric method for the determination of Cu(II) with DPKBH was developed in stationary conditions and, after this, it was adapted to flow injection analysis, using a manual commutator. Subsequently, a spectrophotometric method was developed to determine Fe(II), Fe(III) and Cu(II) in the same sample, in stationary conditions, using masking reagents. This method was also adapted to flow injection analysis, using multicommutation and binary sampling. Finally, Cu(II), Fe(II) and Fe(III) were determined in sediments from Guarapiranga reservoir. The obtained results were compared with the ICP-OES standard methods, showing a good agreement into a 95% confidence level (t-test).

Desenvolveu-se um método espectrofotométrico para determinação de íons Cu(II), Fe(II) e Fe(III) com o reagente cromogênico di-2-piridil cetona benzoilhidrazona (DPKBH), em condições estacionárias e em fluxo. Fez-se a caracterização estrutural e estequiométrica do complexo de Cu(II) com DPKBH usando-se técnicas espectroscópicas de infravermelho e massas, além de análise térmica e elementar. Estudou-se, ainda, a estequiometria dos complexos de Fe(II) e Fe(III) com DPKBH utilizando espectrometria de massas com ionização por electrospray. Desenvolveu-se, preliminarmente, um método espectrofotométrico para a determinação de íons Cu(II) com DPKBH e aplicou-se em amostras de aguardente. Posteriormente, adaptou-se para análise por injeção em fluxo, utilizando-se injetor comutador manual. Em seguida, desenvolveu-se em condições estacionárias um método espectrofotométrico para determinação de Fe(II) e Fe(III) e Cu(II) em uma mesma amostra, com o uso de agentes mascarantes. Fez-se também a adaptação do método para análise em fluxo empregando multicomutação e amostragem binária. Finalmente, determinou-se a concentração de íons Cu(II), Fe(II) e Fe(III) em amostras sintéticas e Cu(II) e ferro total em amostras de sedimento coletadas no reservatório de Guarapiranga. Os resultados obtidos foram comparados com o método de referência de ICP-OES, apresentando concordância para um nível de confiança de 95% da média. / A spectrophotometric method was developed to the determination of Cu(II), Fe(II) and Fe(III) with the chromogenic reagent di-2pyridyl ketone benzoylhydrazone (DPKBH) in stationary conditions as a flow injection process. The structural characterization and the stoichiometry of Cu(II)/DPKBH complex were achieved using infrared spectrometry, mass spectrometry, thermal and elementar analysis. Toe stoichiometry of the Fe(II) and Fe(III) complexes with DPKBH was studied by electrospray ionization mass spectrometry. The spectrophotometric method for the determination of Cu(II) with DPKBH was developed in stationary conditions and, after this, it was adapted to flow injection analysis, using a manual commutator. Subsequently, a spectrophotometric method was developed to determine Fe(II), Fe(III) and Cu(II) in the same sample, in stationary conditions, using masking reagents. This method was also adapted to flow injection analysis, using multicommutation and binary sampling. Finally, Cu(II), Fe(II) and Fe(III) were determined in sediments from Guarapiranga reservoir. The obtained results were compared with the ICP-OES standard methods, showing a good agreement into a 95% confidence level (t-test).

Zahlreiche Studien belegen, dass Maillard-Reaktionsprodukte (MRP) in vivo einen Einfluss auf den physiologischen Metallionenhaushalt haben können. Da bisher noch keine Korrelation zwischen dem Entstehen von definierten MRP und einem erhöhten Metallionenbindungsvermögen ermittelt werden konnte, war es das Ziel dieser Arbeit, die Komplexbildungseigenschaften der ausgewählten MRP Nε-Carboxymethyllysin, Isomaltol und Maltosin sowie deren Strukturanaloga Maltol, Deferipron, Mimosin und Pyridosin mit den physiologisch relevanten Metallionen Cu(II), Zn(II), Fe(III), Al(III) und Mn(II) zu untersuchen. Dazu wurden die MRP Nε-Carboxymethyllysin und Maltosin sowie die parallel untersuchten Substanzen Pyridosin, Maltosin-3-benzylether, Nα-Hippuryl- und Nα-Acetylmaltosin in ausreichender Menge und Reinheit synthetisiert. Dabei gelang es, für Maltosin und Pyridosin neue und effiziente Synthesewege zu entwickeln, bei welchen zum ersten Mal beide Substanzen gezielt aufgebaut wurden. Die Komplexbildungskonstanten der Liganden mit den Metallionen wurden pH-potentiometrisch bestimmt (I[KNO3] = 0,15 M; θ = 25 °C). Durch die Auswertung der Protonierungskonstanten der gebildeten Komplexe und das Vermessen geeigneter Derivate konnten für die untersuchten Komplexe zusätzlich die Koordinationsstellen der Liganden aufgeklärt werden. Die Untersuchungen zu den Komplexbildungseigenschaften bestätigten erstmals die Vermutung, dass MRP in der Lage sind, Metallionen zu binden. Dabei wurde weiterhin ermittelt, dass die Bindung von Cu(II) durch Nε-Carboxymethyllysin und von Fe(III), Al(III) und Cu(II) durch Maltosin durchaus von physiologischer Relevanz sind. Die Bedeutung der Ergebnisse wurde qualitativ durch Versuche mit Maltosin-derivatisiertem Rinderserumalbumin unterstrichen. Als besonderes Ergebnis der Arbeit ist herauszustellen, dass das MRP Maltosin und die Verbindung Pyridosin deutlich stabilere Komplexe mit Fe(III) bilden als das zur Fe(III)-Chelattherapie eingesetzte Medikament Deferipron. Diese festgestellte Eigenschaft bietet interessante Perspektiven für zukünftige Studien zur möglichen Anwendung von z. B. Maltosin als Pharmakon. / Several studies show that Maillard reaction products (MRP) may influence the physiological metal ion balance. But none of these studies prove a correlation between the formation of defined MRP and an enhanced metal ion binding. Therefore it was the aim of this work to investigate the complex formation characteristics of the selected MRP Nε-carboxymethyllysine, isomaltol and maltosine as well as the structural analogues maltol, deferiprone, mimosine and pyridosine with the physiological relevant metal ions Cu(II), Zn(II), Fe(III), Al(III) and Mn(II). For that purpose the MRP Nε-carboxymethyllysine and maltosine plus the parallel analysed substances pyridosine, maltosine-3-benzylether, Nα-hippuryl- and Nα-acetylmaltosine were synthesised. Thereby new and efficient syntheses for maltosine and pyridosine were developed. The stability constants of the ligands with the metal ions were determined by pH-potentiometry (I(KNO3) = 0,15 M; θ = 25 °C). Furthermore the donor atoms within the formed complexes were determined by the evaluation of the protonation constants of the formed complexes and by the analysis of adequate derivatives. The studies to the complex formation characteristics confirm for the first time the assumption, that MRP are able to form stable complexes with metal ions. Withal it was ascertained that the coordination of Cu(II) by Nε-carboxymethyllysine and of Fe(III), Al(III) and Cu(II) by maltosine may be of physiological relevance. The significance of the results was pointed out by experiments with maltosine derivatised bovine serum albumine. The fact that the MRP maltosine and the compound pyridosine form more stable complexes with Fe(III) as the medicament for the Fe(III) chelate therapy deferiprone is a particular result of this work. This property affords interesting perspectives for future studies about a possible appliance of e.g. maltosine as pharmaceutical.