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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Adsorption of Cu(II) and Ni(II) Ions on Functionalized Colloidal Silica Particles Model Studies for Wastewater Treatment / Fonctionnalisation de silices colloïdales pour l’adsorption de cations métalliques Cu(II) and Ni(II) Elaboration de composites pour le traitement des eaux

Singhon, Rattiya 08 April 2014 (has links)
Ce doctorat porte sur la fonctionnalisation de silices colloïdales en vue de la rétention de micropolluants métalliques dans des effluents. Les nanoparticules et microparticules ouvrent des potentialités d’application dans de nombreux secteurs industriels (chimie, environnement, pharmacie...). Ainsi, ces travaux de recherche portent sur la synthèse et la caractérisation de matériaux composites submicroniques : il s’agit de silices colloïdales sur lesquelles sont greffés des silanes ou supportés des polysaccharides. Une des applications de ces travaux de recherche porte sur l’adsorption de métaux de transition sur ces composites en solution aqueuse. Dans le cadre de ce doctorat, les caractéristiques des composites sont définies par leur morphologie de surface, par l’étude des groupements fonctionnels présents, par détermination de leurs surfaces spécifiques ainsi qu’en solution aqueuse par détermination de leurs diamètres hydrodynamiques et de leurs potentiels zéta. Dans un premier temps, la fonctionnalisation de la silice a permis le greffage de groupements carboxyliques et amines dont tes taux de greffage obtenus ont été respectivement de 0,47 µmol/m² et 3,86 µmol/m². En présence de groupements amines, le potentiel  des composites est positif jusqu’ à pH 9 alors qu’il est négatif dès pH 3 pour des silices non fonctionnalisées. Dans un second temps, la silice est supportée par du chitosane dont le degré de désacétylation est de 77%. Conjointement, l’encapsulation de la silice est réalisées par du chitosane sur lequel des fonctions carboxyliques ont été greffées. La morphologie des particules est alors modifiée, leurs diamètres hydrodynamiques sont plus élevés et leurs potentiels  sont positifs jusqu’ à pH basique. La rétention d’ions métalliques (Cu(II) et Ni(II)) par ces composites à différents pH est ensuite étudiée. Pour chacun des cations métalliques, les capacités d’adsorption sont déterminées ainsi que les cinétiques d’adsorption. L’application de plusieurs modèles d’isotherme d’équilibre a été réalisée. Dans le cas de Cu(II), à pH 5, les meilleures capacités d’adsorption sont obtenues pour des silices supportées par du chitosane greffé : la capacité de rétention des ions Cu(II) est de 270 mg/g à pH 5. De même, c’est ce composite qui permet la meilleurs rétention des ions Ni(II) à pH 7 avec une capacité d’adsorption de 263 m/g. Concernant la cinétique, le modèle de réaction de surface du pseudo-second ordre s’applique bien aux résultats expérimentaux. / This study is focused on the preparation of three types of silica-based composites for the capture of Cu(II) and Ni(II) ions. The first strategy consists in coating chitosan on colloidal fumed silica after acidic treatment yielding the composite SiO2+CS. The second strategy can be separated into two routes: the first one involves surface grafting of silica with aminopropyltriethoxysilane to obtaining silica particles covered by amino groups (SiO2(NH2)). The second one involves in surface condensation of triethoxysilylbutyronitrile, followed by acidic hydrolysis of the surface-bound nitrile groups affording silica particles covered by carboxyl groups (SiO2(CO2H)). In the last step, chitosan has been grafted on the surface bound NH2 or -CO2H groups yielding the composites SiO2(NH2)+CS or SiO2(CO2H)+CS. The third strategy involves in the modified CS surface with -CO2H groups, followed by coating onto the non-modified silica nanoparticles to obtain the composite SiO2+CS(CO2H). The novel hybrid materials were characterized by IR spectroscopy, scanning electron microscopy, atomic force microscopy, and zeta potential measurements. Batch experiments were conducted to study the sorption performance of these composites for Cu(II) and Ni(II) removal from aqueous solution at optimum pH at 298 K. The kinetics were evaluated utilizing pseudo-first-order, pseudo-second-order, and intraparticle diffusion models. The adsorption kinetics followed the mechanism of the pseudo-second-order equation for all types of adsorbents. The adsorption isotherms were evaluated utilizing Langmuir, Freundlich, and Temkin models. The best interpretation for equilibrium data was given by Langmuir isotherm model. This study demonstrates that the adsorption capacities for Cu(II) ion is more efficient for the SiO2+CS (256 mg g-1) compared to SiO2(NH2) (75 mg g-1). However, the carboxyl grafted CS-coated silica (SiO2+CS(CO2H) exhibited an excellent adsorption capacity (333 mg g-1). In case of Ni(II), based on Langmuir isotherm the maximum adsorption capacity found to be 182 mg g-1for SiO2+CS, and 210 mg g-1 for SiO2(CO2H) + CS. Using single-metal solutions, these adsorbents were found to have an affinity for metal ions in order as Cu(II) > Ni(II). The adsorption of Cu(II) ion by SiO2+CS was affected by the nature of the respective anion. Application of these composite materials to remove Cu(II) and Ni(II) from aqueous solution was shown to be more efficient than the adsorption capacities of many sorbents probed by other research groups.
12

Estudo de metalofármacos antiinflamatórios de cobre e dos materiais híbridos resultantes de suas imobilizações no hidróxido duplo lamelar hidrotalcita: síntese, caracterização e avaliação da atividade farmacológica / Studies of Anti-inflammatory Copper-based Drugs and Corresponding Hybrid Materials from their Immobilization on the Layered Double Hydroxide Hydrotalcite: Synthesis, Characterization and Evaluation of Pharmacological Activities

Gordijo, Cláudia Regina 04 October 2007 (has links)
Os fármacos antiinflamatórios não-esteróides (FAINEs) são amplamente utilizados no combate a processos inflamatórios e dores, mas apresentam restrição de uso em razão de sérios efeitos colaterais sobre o trato gastrointestinal. A atividade biológica de complexos metálicos tem sido objeto de pesquisa de grande interesse na área de metalofármacos e compostos do tipo Cu(II)-FAINEs apresentam boa atividade antiinflamatória e efeitos colaterais reduzidos em relação aos fármacos orgânicos. Nesse trabalho, com o objetivo de contribuir para ampliar os estudos sobre o desenvolvimento de alternativas aos FAINEs, foram preparados e caracterizados complexos cobre(lI) com ibuprofeno, indometacina, naproxeno, sulindaco, meloxicam. Os compostos foram imobilizados em Hidrotalcita, um hidróxido duplo lamelar (HDL) de magnésio e alumínio (Mg/AI = 3) que é biocompatível e tem uso como antiácido estomacal. As interações dos metalofármacos com o HDL geraram materiais híbridos bioinorgânicos do tipo Cu-FAINElHDL, nos quais os complexos podem estar presentes de duas maneiras: intercalados entre as Ia meias ou adsorvidos nas superfícies externas do hidróxido duplo lamelar, dependendo do solvente utilizado. A intercalação de complexos neutros é favorecida em solvente misto álcooVamida no qual a Hidrotalcita sofre esfoliação promovida por um processo de hidrólise da amida. A estabilidade alguns dos complexos e dos materiais híbridos em condições gástricas simuladas (pH e temperatura) e as atividades antiinflamatória, analgésica e ulcerogênica in vivo dos sistemas contendo indometacina (Indo) foram investigadas. A intercalação do complexo Cu-Indo no HDL favorece sua estabilização, contribuindo para potencializar a sua atividade farmacolágica. Os materiais híbridos bioinorgânicos obtidos neste trabalho apresentam propriedades interessantes com vistas a potencial aplicação como sistemas de liberação controlada de fármacos. / Non-steroidal anti-inflammatory drugs are widely consumed to treat inflammatory diseases and pain but their clinical use are limited due to serious side-effects on the gastrointestinal tract. The bioactivity of metal complexes exhibits great interest in metal-based drug research. Cu(II)-NSAID compounds show good anti-inflammatory property and decreased side-effects compared to their organic parent drugs. This work aimed to contribute for development of alternative NSAIDs. Cu-NSAlD compounds containing the drugs Ibuprofen, Indomethacin, Naproxen, Sulindac and Meloxicam were synthesized and characterized. The compounds were also immobilized on Hydrotalcite, a layered double hydroxide (LDH) of magnesium and aluminum (Mg/Al = 3), that is biocompatible and used as stomach antacid. The interactions of the copper drugs with LDH led to Cu-NSAID/LDH- bioinorganic hybrid materiais. Two kinds of complex-LDH interactions were observed by changing the solvent: intercalation between LDH layers or adsorption on the LDH external surfaces. The intercalation of neutral complexes is favored in an alcohollamide solvent mixture where Hydrotalcite undergoes exfoliation process promoted by the amide hydrolysis. The stability of some complexes and their correspondent hybrid materials under gastric conditions (pH and temperature) and also in vivo anti-inflammatory, analgesic and ulcerogenic activities for Indomethacin (Indo)-containing systems were investigated. The stabilization of the Cu-Indo structure is promoted by intercalation of the complex into the LDH layers, contributing to increase its pharmacological activity. The bioinorganic hybrid materials here investigated also exhibit interesting properties for applications as controlled drug delivery systems.
13

Synthèse de ligands et liquides ioniques dérivés de molécules naturelles : Application à la complexation des cations métalliques - Application à l’extraction liquide-liquide de métaux. / Synthesis of ligands and ionic liquids derived from betaine : Application to metal ions complexation - Application to metal ions liquid-liquid extraction

Messadi, Ahmed 25 October 2013 (has links)
Ces travaux abordent, d'une part l'étude de la coordination du cuivre(II) et nickel(II) avec un ligand heptadenté tripode, et d'autre part la synthèse et la caractérisation de liquides ioniques dérivés de la bétaïne.Tout d'abord, le ligand heptadenté, le tris[(L)-alanyl-2-carboxamidoéthyl]amine (H3trenala), a été synthétisé sous forme de sel de chlorure ; ses constantes de protonation ainsi que les constantes de stabilité des complexes de Cu(II) et de Ni(II) ont été déterminées par potentiométrie. Des espèces complexes mononucléaires dans lesquels le ligand est protonné ([Cu(H5trenala)]4+, [M(H4trenala)]3+), neutre ([M(H3trenala)]2+) ou déprotonné ([M(H2trenala)]+, [M(Htrenala)]) (M = Cu2+ ou Ni2+) ont été mises en évidence. Seul le Cu(II) donne des espèces dinucléaires dans lesquels le ligand est uniquement déprotonné ([Cu2(H2trenala)]2+, [Cu2(Htrenala)]2+, [Cu2(trenala)]+, [Cu2(trenala)(OH)]). A l'état solide, deux complexes dinucléaires de cuivre(II) ont pu être isolés et caractérisés (IR, UV-Vis, masse électrospray, ATG). L'étude des propriétés catalytiques de ces deux complexes montre une faible activité vis-à-vis de la réaction d'oxydation du catéchol.La seconde partie de ce travail présente la synthèse de liquides ioniques constitués par des synthons cationiques dérivés d'ester de glycine-bétaïne {trialkyl(2-éthoxy-2-oxoéthyl)ammonium (alkyl = éthyl, n-propyl et n-butyl), N-(1-méthylpyrrolidyl-2-éthoxy-2oxoéthyl)ammonium} et des anions inorganiques {bis(trifluorosulfonyl)imide (NTf2-), dicyanamide (Dca-), tétrafluoroborate (BF4-)}. Les influences de la longueur de la chaîne alkyle portée par l'atome d'azote ammonium et de la nature de l'anion associé sur les propriétés physicochimiques telles que la densité, les températures de fusion, de transition vitreuse et de décomposition, la viscosité et les fenêtres électrochimiques, ont été déterminées. De plus, des sels fondus ont pu être générés à partir de ces cations organiques associés aux anions tetrafluoroborate, dicyanamide, hexafluorophosphate (PF6-) et perchlorate (ClO4-), et leurs propriétés physicochimiques ainsi que leurs structures cristallines ont été déterminées.Ensuite, les liquides ioniques hydrophobes sont utilisés pour l'extraction des cations métalliques [Cu(II), Ni(II), Cd(II) et Pb(II)] en phase aqueuse. Cette étude montre que les rendements d'extraction d'ions métalliques, déterminés par mesure de la concentration résiduelle en métal en phase aqueuse, dépendent de la longueur de la chaîne alkyle portée par l'atome d'azote ammonium et des propriétés chélatantes de l'anion. Les rendements les plus élevés ont été obtenus avec les liquides ioniques dont l'anion possède des propriétés chélatantes. L'étude du transfert du métal montre qu'il est dépendant de l'hydrophobicité du synthon cationique. Une augmentation de l'hydrophobicité du synthon cationique conduit à une augmentation du rendement d'extraction, tout en limitant l'échange ionique et en privilégiant une extraction par paires d'ions. Enfin, l'électrodéposition en phase liquide ionique et la désextraction liquide-liquide des ions métalliques ont été étudiées. / This work deals with copper(II) and nickel(II) complexation of a polydentate tripodal ligand and with, on a second part, the synthesis and characterization of ionic liquids derived from betaine and their use in liquid-liquid extraction.On the first part, a heptadentate ligand, tris[(L)-alanyl-2-carboxamidoethyl]amine (H3trenala), has been synthesized as its tetrahydrochloride salt; its protonation constants and the stability constants of the copper(II) and nickel(II) chelates have been determined by potentiometry. Mononuclear species with protonated, neutral, or deprotonated forms of the ligand, [Cu(H5trenala)]4+, [M(H4trenala)]3+, [M(H3trenala)]2+, [M(H2trenala)]+, and [M(Htrenala)] (M=Cu2+ and Ni2+) have been detected in all cases, while only Cu2+ gives dinuclear [Cu2(H2trenala)]2+, [Cu2(Htrenala)]2+, [Cu2(trenala)]+, and [Cu2(trenala)(OH)] species. Two dinuclear copper(II) complexes have been prepared and characterized by spectroscopic techniques (IR, UV-Vis, mass electro-spray) and thermogravimetric analysis. These two dinuclear copper(II) complexes have revealed weak catalytic activity in catechol oxidation.On the second part, a series of salts based on ethyl ester betaine derivatives[trialkyl(2-ethoxy-2-oxoethyl)ammonium or N-(1-methylpyrrolidyl-2-ethoxy-2-oxoethyl)ammonium cations] with alkyl chains [ethyl, n-propyl and n-butyl] have been synthesized. These cations generate hydrophobic ionic liquids with bis(trifluoromethylsulfonyl)imide, tetrafluoroborate or dicyanamide anions. The influence of the alkyl chain length and the chemical nature of the counteranion on physicochemical properties such as density, melting point, glass transition and decomposition temperatures, viscosity, and electrochemical window have been investigated. In addition, molten salts have been generated from these organic cations with hexafluorophosphate, perchlorate, tetrafluoroborate or dicyanamide anions. Their physicochemical properties and crystal structure have been investigated.The extraction of the different metal cations (Cu2+, Ni2+, Cd2+ and Pb2+) in aqueous solution by hydrophobic ionic liquids synthesized was performed. The extraction yields, determined by the measurements of the residual metal concentration in aqueous solution, depend not only the length of the alkyl chain of the ammonium but also on the nature of the associated anion. The most promising results are obtained with ILs whose anion has a chelating ability. The mechanism of metal transfer has been studied and was related to the hydrophobicity of the cationic synthon. Increasing the hydrophobicity of the cationic synthon leads to an increase of extraction yield, thus limiting the ion exchange and promoting ion pairing extraction. Electrodeposition in ionic liquid phase and liquid-liquid desextraction of metallic ions have also been investigated.
14

Estudo de metalofármacos antiinflamatórios de cobre e dos materiais híbridos resultantes de suas imobilizações no hidróxido duplo lamelar hidrotalcita: síntese, caracterização e avaliação da atividade farmacológica / Studies of Anti-inflammatory Copper-based Drugs and Corresponding Hybrid Materials from their Immobilization on the Layered Double Hydroxide Hydrotalcite: Synthesis, Characterization and Evaluation of Pharmacological Activities

Cláudia Regina Gordijo 04 October 2007 (has links)
Os fármacos antiinflamatórios não-esteróides (FAINEs) são amplamente utilizados no combate a processos inflamatórios e dores, mas apresentam restrição de uso em razão de sérios efeitos colaterais sobre o trato gastrointestinal. A atividade biológica de complexos metálicos tem sido objeto de pesquisa de grande interesse na área de metalofármacos e compostos do tipo Cu(II)-FAINEs apresentam boa atividade antiinflamatória e efeitos colaterais reduzidos em relação aos fármacos orgânicos. Nesse trabalho, com o objetivo de contribuir para ampliar os estudos sobre o desenvolvimento de alternativas aos FAINEs, foram preparados e caracterizados complexos cobre(lI) com ibuprofeno, indometacina, naproxeno, sulindaco, meloxicam. Os compostos foram imobilizados em Hidrotalcita, um hidróxido duplo lamelar (HDL) de magnésio e alumínio (Mg/AI = 3) que é biocompatível e tem uso como antiácido estomacal. As interações dos metalofármacos com o HDL geraram materiais híbridos bioinorgânicos do tipo Cu-FAINElHDL, nos quais os complexos podem estar presentes de duas maneiras: intercalados entre as Ia meias ou adsorvidos nas superfícies externas do hidróxido duplo lamelar, dependendo do solvente utilizado. A intercalação de complexos neutros é favorecida em solvente misto álcooVamida no qual a Hidrotalcita sofre esfoliação promovida por um processo de hidrólise da amida. A estabilidade alguns dos complexos e dos materiais híbridos em condições gástricas simuladas (pH e temperatura) e as atividades antiinflamatória, analgésica e ulcerogênica in vivo dos sistemas contendo indometacina (Indo) foram investigadas. A intercalação do complexo Cu-Indo no HDL favorece sua estabilização, contribuindo para potencializar a sua atividade farmacolágica. Os materiais híbridos bioinorgânicos obtidos neste trabalho apresentam propriedades interessantes com vistas a potencial aplicação como sistemas de liberação controlada de fármacos. / Non-steroidal anti-inflammatory drugs are widely consumed to treat inflammatory diseases and pain but their clinical use are limited due to serious side-effects on the gastrointestinal tract. The bioactivity of metal complexes exhibits great interest in metal-based drug research. Cu(II)-NSAID compounds show good anti-inflammatory property and decreased side-effects compared to their organic parent drugs. This work aimed to contribute for development of alternative NSAIDs. Cu-NSAlD compounds containing the drugs Ibuprofen, Indomethacin, Naproxen, Sulindac and Meloxicam were synthesized and characterized. The compounds were also immobilized on Hydrotalcite, a layered double hydroxide (LDH) of magnesium and aluminum (Mg/Al = 3), that is biocompatible and used as stomach antacid. The interactions of the copper drugs with LDH led to Cu-NSAID/LDH- bioinorganic hybrid materiais. Two kinds of complex-LDH interactions were observed by changing the solvent: intercalation between LDH layers or adsorption on the LDH external surfaces. The intercalation of neutral complexes is favored in an alcohollamide solvent mixture where Hydrotalcite undergoes exfoliation process promoted by the amide hydrolysis. The stability of some complexes and their correspondent hybrid materials under gastric conditions (pH and temperature) and also in vivo anti-inflammatory, analgesic and ulcerogenic activities for Indomethacin (Indo)-containing systems were investigated. The stabilization of the Cu-Indo structure is promoted by intercalation of the complex into the LDH layers, contributing to increase its pharmacological activity. The bioinorganic hybrid materials here investigated also exhibit interesting properties for applications as controlled drug delivery systems.
15

Σχεδιασμός, σύνθεση και κρυσταλλική μηχανική συμπλόκων ενώσεων του Cu(II) με 2-φαινυλοϊμιδαζόλιο ως υποκαταστάτη

Κίτος, Αλέξανδρος 19 July 2012 (has links)
Βασικός στόχος της παρούσης Διπλωματικής Εργασίας ήταν η μελέτη της κρυσταλλικής μηχανικής συμπλόκων ενώσεων του CuII με το 2-φαινυλοϊμιδαζόλιο ως υποκαταστάτη. Η κρυσταλλική μηχανική μπορεί να θεωρηθεί ως ο κλάδος της υπερμοριακής χημείας στη στερεά κατάσταση. Η υπερμοριακή χημεία (supramolecular chemistry) είναι μια από τις πλέον δημοφιλείς και γρήγορα αναπτυσσόμενες περιοχές της πειραματικής χημείας. Χαρακτηρίζεται ως η χημεία των ασθενών διαμοριακών δυνάμεων και εστιάζει στη δομή και λειτουργία χημικών συστημάτων με υψηλή πολυπλοκότητα (υπερμόρια) που προκύπτουν από το συνδυασμό δύο ή περισσοτέρων διακριτών χημικών ειδών (μορίων, ιόντων) και συγκρατούνται με ασθενείς (και αντιστρεπτές) διαμοριακές δυνάμεις (π.χ. αλληλεπιδράσεις π-π, δεσμούς υδρογόνου, υδρόφοβες αλληλεπιδράσεις, δυνάμεις van der Waals, αλληλεπιδράσεις διπόλου-διπόλου, δεσμούς ένταξης μετάλλου-υποκαταστάτη κλπ). Ένα σημαντικό πεδίο της υπερμοριακής χημείας είναι αυτό της κρυσταλλικής μηχανικής (crystal engineering) που αναφέρεται στη στρατηγική σχεδιασμού ενός κρυσταλλικού υλικού με επιθυμητές ιδιότητες και βασίζεται στην κατανόηση και τον έλεγχο των διαμοριακών αλληλεπιδράσεων των μορίων στην κρυσταλλική κατάσταση. Καταρχήν, πραγματοποιήθηκε η σύνθεση συμπλόκων ενώσεων με γενικό τύπο ΜΙΙ/Χ-/L, όπου ΜΙΙ = CuII, X- = Cl-, NO3-, ClO4-, SiF62-, SO42- και L = 2-φαινυλοϊμιδαζόλιο. Από τις συνθετικές παραμέτρους που μεταβάλλαμε -γραμμομοριακή αναλογία μετάλλου:υποκαταστάτη, πολικότητα του διαλύτη (MeOH, EtOH, MeCN, DMF, CH2Cl2), συνθήκες θερμοκρασίας και μέθοδο κρυστάλλωσης– απομονώσαμε και χαρακτηρίσαμε τα σύμπλοκα: (LH)+(NO3)- (1), [CuCl2L2] (2), [Cu2(OMe)2(L)4(NO3)2]∙2MeOH (3∙2MeOH), [Cu(L)4](NO3)2 (4), [Cu2(OMe)2(L)4](ClO4)2 (5), [Cu(L)4](ClO4)2 (6), [Cu2(OMe)2(L)4]SiF6 (7) και [Cu2(SO4)2(L)4] (8). Με τη βοήθεια της κρυσταλλογραφικής ανάλυσης με ακτίνες Χ των ανωτέρων συμπλόκων, διαπιστώθηκε ότι οι διαμοριακές αλληλεπιδράσεις που είναι υπεύθυνες για την υπερμοριακή οργάνωση των δομών τους είναι ισχυροί και ασθενείς δεσμοί υδρογόνου και αλληλεπιδράσεις τύπου π-π. Αναλυτικότερα: • Σταθερά μοτίβα διαμοριακών αλληλεπιδράσεων (συνθόνια) σχηματίζονται μεταξύ των τεκτονίων N-H των ιμιδαζολικών δακτυλίων και των ανόργανων ανιόντων X- (Cl-, NO3-, ClO4-, SiF62-, SO42-) ή/και πλεγματικών μορίων διαλύτη, οδηγώντας σε 1D, 2D και 3D υπερμοριακές δομές. • Οι δομές σταθεροποιούνται περαιτέρω μέσω ενδομοριακών (σύμπλοκα 4, 5 και 6) και διαμοριακών (σύμπλοκο 2) αλληλεπιδράσεων τύπου π-π. • Το μέγεθος και το φορτίο των ανιόντων δεν επηρεάζουν τους δομικούς πυρήνες των μορίων, σε αντίθεση με την υπερμοριακή οργάνωση που επηρεάζεται καθοριστικά και οδηγεί σε 2D και 3D αρχιτεκτονικές. / The main target of this diploma thesis was the crystal engineering studies of coordination compounds of CuII using 2-phenylimidazole as ligand. Crystal engineering may be regarded as the solid-state branch of supramolecular chemistry. Supramolecular chemistry is one of the most popular and rapidly developing areas of experimental chemistry. It may be defined as the chemistry of weak intermolecular forces and focuses on the structure and function of chemical systems of high complexity (supermolecules), resulting from the association of two or more discrete chemical species (molecules, ions) held together by weak (and reversible) intermolecular forces (e.g. π-π interactions, hydrogen bonds, hydrophobic interactions, van der Waals forces, dipole-dipole interactions, metal-ligand coordination bonds etc). Crystal engineering is an important field of supramolecular chemistry that refers to the design and synthesis of a crystalline material with desired properties, based on the understanding and exploitation of intermolecular interactions in the crystalline state. Initially the synthesis of coordination complexes with general formula ΜΙΙ/Χ-/L [ΜΙΙ = CuII, X- = Cl-, NO3-, ClO4-, SiF62-, SO42- and L =2-phenylimidazole] took place. By altering the parameters of synthesis –metal:ligand molar ratio, solvent polarity (MeOH, EtOH, MeCN, DMF, CH2Cl2), temperature, as well as crystallization method– we were able to isolate and study the following complexes: (LH)+(NO3)- (1), [CuCl2L2] (2), [Cu2(OMe)2(L)4(NO3)2]∙2MeOH (3∙2MeOH), [Cu(L)4](NO3)2 (4), [Cu2(OMe)2(L)4](ClO4)2 (5), [Cu(L)4](ClO4)2 (6), [Cu2(OMe)2(L)4]SiF6 (7) και [Cu2(SO4)2(L)4] (8). Based on the X-ray crystal structure determination of the above complexes, it was established that the intermolecular interactions responsible for the supramolecular organization of the structures are strong and weak hydrogen bonds, as well as π-π interactions. Specifically: • Supramolecular synthons between the N-H tectons of imidazole rings and the inorganic anions X- (Cl-, NO3-, ClO4-, SiF62-, SO42-) or/and lattice solvent molecules are formed, leading to 1D, 2D and 3D supramolecular structures. • The structures are further stabilized by intramolecular (complexes 4, 5 and 6) and intermolecular (complex 2) π-π interactions. • The size and charge of the anions X- used does not affect the structural core of the complexes, in contrast to their supramolecular organization which is decisively affected, leading to 2- and 3D architectures.
16

Complexos de Fe(II), Mn(II), Cu(II) e Zn(II) derivados de um ligante do tipo oxamato funcionalizado: síntese e caracterização

Maciel, Jhonny Willians de Oliveira 28 September 2018 (has links)
Submitted by Onia Arantes Albuquerque (onia.ufg@gmail.com) on 2018-11-06T13:54:30Z No. of bitstreams: 2 Dissertação - Jhonny Willians de Oliveira Maciel - 2018.pdf: 3229754 bytes, checksum: 23b20bfd316d193ccfafa525bf314c79 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2018-11-07T09:38:43Z (GMT) No. of bitstreams: 2 Dissertação - Jhonny Willians de Oliveira Maciel - 2018.pdf: 3229754 bytes, checksum: 23b20bfd316d193ccfafa525bf314c79 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-11-07T09:38:43Z (GMT). No. of bitstreams: 2 Dissertação - Jhonny Willians de Oliveira Maciel - 2018.pdf: 3229754 bytes, checksum: 23b20bfd316d193ccfafa525bf314c79 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2018-09-28 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / New supramolecular systems based on metal complexes of formula [Fe(H2pcpa)2(H2O)2] (3), [Mn(Hpcpa)(H2O)3]n•1/2H2O (4), [Zn(Hpcpa)(H2O)3]n•1/2H2O (5) and [Cu2(Hpcpa)2(bipy)2]•5,6H2O (6) [H2pcpa- and Hpcpa2- ion derivative of EtH2pcpa (1) = N-(4-carboxyphenyl)oxamic ethyl ester] have been synthesized and describe in this work. The structure of 3 consists of discrete Fe(II) units, each metal ion is six-coordinate in a distorted octahedral environment with four oxamate-oxygens from a H2pcpa- ligand in the basal plane and two water molecules in the apical position. 4 and 5 is a neutral zigzag chain of Mn(II) and Zn(II) ions, respectively, bridged by Hpcpa2- ligands exhibiting the bidentate/monodentate coordination mode. Each metal ion is building a somewhat distorted octahedral surrounding. The distance between metals ions intrachain is 11.456 Å (4) and 11.325 Å (5). Complex 6 consists of a dimer in which the Cu(II) ions is found in a square-shaped pyramidal geometry connected by two Hpcpa2- and the 2,2'-bipyridine as a terminal ligand. / Foram obtidos novos sistemas supramoleculares baseados em compostos de coordenação com o ligante ácido N-(4-carboxifenil) oxâmico etil éster (EtH2pcpa/1) e os metais Fe(II), Mn(II), Cu(II) e Zn(II). As sínteses, caracterizações espectroscópicas e elucidação das estruturas cristalinas de quatro compostos inéditos de fórmula [Fe(H2pcpa)2(H2O)2] (3), [Mn(Hpcpa)(H2O)3]n•1/2H2O (4), [Zn(Hpcpa)(H2O)3]n•1/2H2O (5) e [Cu2(Hpcpa)2(bipy)2]•5,6H2O (6) foram descritas nesse trabalho. O complexo 3 formou monocristais de cor laranja amarronzada, cuja a estrutura consiste em um monômero de Fe(II). Cada íon de Fe(II) é hexacoordenado com esfera de coordenação composta de duas moléculas de água posicionadas em trans e quatro oxigênios-oxamato de dois ligante H2pcpa-. Os compostos 4 e 5 formaram monocristais transparentes incolores cujas estruturas cristalinas são formadas por cadeias em ziguezague neutras de íons Mn(II) e Zn(II), respectivamente. Cada íon metálico está hexacoordenado com as três moléculas de água posicionadas em Meridional, dois oxigênios-oxamato de um ligante Hpcpa2- e um oxigênio-carboxilato de um outro grupo do Hpcpa2-. A distância entre os metais intracadeia Mn...Mn no complexo 4 é de 11,456 Å e Zn...Zn no complexo 5 é de 11,325 Å. O complexo 6 formou monocristais azuis, a estrutura consiste em um dímero em que o íon de Cu(II) encontra-se penta coordenado em uma geometria piramidal de base quadrada com dois íons de Cu(II) ligados por dois ligantes Hpcpa2- e com o ligante 2,2'-bipiridina atuando como ligante terminal.
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Síntese, Análise Estrutural e Caracterização de Novos Compostos de Coordenação de Fenilseleninato de Cobre(II) / Synthesis, Structure Analysis e Characterization of New Coordination Compounds of Copper(II) Phenylseleninato

Leal, Rodrigo Rozado 25 March 2010 (has links)
In this work were synthesized and studied four new coordination compounds of copper(II) with phenylseleninato ligand, three of them polymeric and one molecular. The reaction of phenylseleninic acid with copper(II) acetate led to microcrystalline light blue powder of polymeric compound catena-poli-[Cu(μ2-O2SePh)2], 1. That powder was used to obtain crystalls of 1 and three others: catena-poli-[Cu(μ2-O2SePh)2(NH3)], 2, obtained by the dissolution of 1 in dmf and aqueous ammonia, catena-poli-[Cu(μ2-O2SePh)2(NC5H5)]·NC5H5, 3, obtained by the dissolution of 1 in pyridine and aqueous ammonia, and poli-[Cu(O2SePh)2(NH3)2(H2O)2], 4, obtained by the dissolution of 1 in water and aqueous ammonia. Compound 1 is a two-dimensional coordination polymer with layers formed by the phenylseleninato double bridges between copper(II) units. The copper(II) centers in the same layer form a (4,4) net topology. Magnetic susceptibility measurements of the crystalline sample of 1 was carried out on a SQUID magnometer and strong ferromagnetic coupling was verified between 10 and 6.3 K. Below 6.3 K was verified a weak antiferromagnetic interactions between partially ordered ferromagnetic layers. All the new compounds were characterized by X-ray diffraction, infrared spectroscopy and elemental analysis. Compounds 2 and 3 have supramolecular nature due to hydrogen bonds in those structures. Only compound 3 is a one-dimensional coordination polymer. / Neste trabalho foram sintetizados e estudados quatro novos compostos de coordenação de cobre(II) com o ligante fenilseleninato, três deles poliméricos e um molecular. A reação do ácido fenilselenínico com acetato de cobre(II) originou um pó microcristalino e azul-claro, referente ao composto polimérico catena-poli-[Cu(μ2-O2SePh)2], 1. Esse foi o composto de partida para a obtenção de cristais de 1, além da obtenção de outros três compostos cristalinos: catena-poli-[Cu(μ2-O2SePh)2(NH3)], 2, obtido pela dissolução de 1 em dmf e amônia aquosa; catena-poli-[Cu(μ2-O2SePh)2(NC5H5)]·NC5H5, 3, obtido pela dissolução de 1 em piridina e amônia aquosa; e [Cu(O2SePh)2(NH3)2(H2O)2], 4, obtido a pela dissolução de 1 em água e amônia aquosa. O composto 1 é um polímero bidimensional em camadas formadas pelo centro metálico e o ligante, no qual os centros de cobre(II) são conectados por pontes duplas de fenilseleninato. Esses centros distribuem-se nas camadas com uma topologia de rede (4,4). Estudos de propriedades magnéticas com um magnetômetro do tipo SQUID evidenciaram fortes interações ferromagnéticas entre 10 e 6,3 K, quando ocorre uma transição antiferromagnética, com queda brusca dos valores do inverso da susceptibilidade magnética, provavelmente por interações antiferromagnéticas entre os planos de Cu(II) paralelos. Todos os novos compostos foram caracterizados por difração de raios-X, espectroscopia de infravermelho e análise elementar. A instabilidade e decomposição, por perda de solvente, das estruturas 2 e 4 impediram estudos de magnetismo, porém a elucidação de suas estruturas cristalinas evidenciaram a existência de interessante caráter supramolecular devido a presença do ligante NH3, em 2, e NH3 e H2O, em 3. As ligações de hidrogênio nesses compostos mostraram-se importantes na manutenção de suas estruturas no estado sólido, assim como na formação de camadas com topologia de rede (4,4). Somente o composto 3 mostrou-se como um polímero de coordenação unidimensional.
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Zeolite encapsulated metal complexes as heterogeneous catalysts for oxidation reactions

Willingh, Gavin Von January 2012 (has links)
>Magister Scientiae - MSc / This study describes the synthesis and characterisation of Cu(II) and V(IV) complexes of tri- and quadridentate ligands L1 and L2 formed by condensation of ethylenediamine with acetylacetonate in 1:1 and 1:2 molar ratio, respectively. Encapsulation of these metal complexes in the nanocage of zoilite-Y generates new heterogeneous catalysts. These catalysts were synthesized employing the flexible ligand method encapsulation technique.The structures of these encapsulated complexes were established on the basis of various physico-chemical and spectroscopic studies. The results indicated that the complexes did not hinder or modify the framework or structure of the zeolite, confirming successful immobilization of Schiff-bases through the voids of zeolite Y.These encapsulated complexes were screened as heterogeneous catalysts for various oxidation reactions such as such as phenol, benzene, styrene and cyclohexene using a green oxidant (H2O2).For comparison, the corresponding neat complexes were screened as potential homogeneous catalysts for these oxidation reactions. The results proved that the corresponding homogeneous systems described here represent an efficient and inexpensive method for oxidation of phenol, benzene, styrene and cyclohexene, having advantages over heterogeneous catalysis are its high activity and selectivity and short reaction times. Its major problem is its industrial application regarding principally the separation of the catalyst from the products.The size of the substrate has a significant effect on the conversion by encapsulated complexes such as in styrene oxidation. Therefore, it was established that steric effects of the substrates play a critical role in the poor reactive nature of the encapsulated complexes.In general, the percentage conversion decreased upon encapsulation of complexes in zeolite Y. All catalysts studied proved to be potential catalysts for the various oxidation reactions.It has been shown in this study that encapsulation can effectively improve product selectivity but requires a longer reaction time in most cases for maximum activity.Furthermore,oxovanadium complexes were more reactive than copper-based catalysts in all oxidation reactions tested in this study.A reaction mechanism study revealed that the activity of the encapsulated and neat complexes occurs through either formation of peroxovanadium (V) or hydroperoxidecopper(II) intermediate species.The studies in this thesis, therefore, conclude that the Cu(II) and V(IV) complexes encapsulated in Y-zeolite are active heterogeneous catalysts for the selective oxidation of various substrates. Encapsulation of the metal complexes in the super cages (-cages) of the zeolite matrix has the advantages of solid heterogeneous catalysts of easy separation and handling, ruggedness, thermostability, reusability (regeneration of the deactivated catalysts) as well as share many advantageous features of homogeneous catalysts.
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Investigação de propriedades no estado sólido de triazenos simétricos 1,3-diarilsubstituídos e complexos com Co(III) e Cu(II) com o ligante 1,3-bis(4-metoxicarbonilfenil)triazenido / Inquiry of properties in the solid state of 1,3-diarilsubstitute and symmetrical triazene complex with Co (III) and Cu (II) bind with 1,3-bis (4-methoxicarbonylphenyl) triazenide

Westphalen, André Bilibio 13 August 2007 (has links)
In this work it was synthesized and determinate the crystalline/molecular structure of two pré ligands triazene simetric: 1,3−bis−(4−acethylamidephenyl)triazene [H3CC(O)NHC6H4NNNC6H4NH(O)CCH3] (1) e o 1,3−bis−(4−ethoxicarbonylphenyl)triazene [H5C2OC(O)C6H4NNNC6H4C(O)OC2H5] (2), one Cu(II) complex (3) and one Co(III) complex (4), being that the two complexes involve the ligand 1,3-bis(4- methoxicarbonylphenyl)triazenide ligands previously deprotonated. Also it was presented the synthesis of pré ligand. The compound H3CC(O)NHC6H4NNNC6H4NH(O)CCH3] (1) crystallizes in monoclinic system, space group C2/c, with cell parameters a=16,0434(8)Å, b=13,0914(6)Å,c=13,0914(6)Å, β = 91.595(2)°, V=3207,2(3)Å 3 ; Z=8. The refinement of this structure converge to the follow discordance indexes wR1=0,0707e wR2=0,1621. The compound [H5C2OC(O)C6H4NNNC6H4C(O)OC2H5] (2) crystallizes in triclinic system, space group P(-1), with cell parameters a=7,65300(10) Å, b=13,4633(2) Å, c=18,0173(3) Å, α = 74,6550(10)°, β = 82,3950(10)° , у = 79,0350(10)°, 1748,5(14) Å 3 ; Z=4. The refinement of this structure converge to the follow discordance indexes wR1=0,1299 e wR2=0,1708. The complex {Cu[H3COC(O)C6H4NNNC6H4C(O)OCH3]2[(CH3)2N]2} (3) crystallizes in triclinic system, space group P(-1) with cell parameters a=7,91600(10)Å, b=9,1596(2)Å, c=13,4476(2)Å, α=105,4130(10)°, β=96,6370(10)°, у=96,1510(10)°, V=923,96(3)Å3; Z=2. The refinement of this structure converge to the follow discordance indexes wR1 = 0,0433, wR2 = 0,1293. The sphere of coordination of Cu(II) ion is formed by two deprotonated triazene ligands and two molecules of dimethylamine. The characteristic effect of Jahn-Teller s distortion expands the coordination geometry of Cu(II) ion to octahedral axially distorted. The complex {Co[H3COC(O)C6H4NNNC6H4C(O)OCH3]3} (4) crystallizes in triclinic system, space group C2/c, with cell parameters a=13,4346(7) Å, b=29,5701(17) Å, c=13,8951(7) Å, β= 107,274(2)°, V= 5271,0(5) Å3; Z=4. The refinement of this structure converge to the follow discordance indexes wR1=0,1081e wR2=0,2278. The structure of this complex presents three ligands triazenides double-toothed. The coordination geometry of the ion Co3+ is octaedric, being distorted and conferring a local asymmetry for the molecule, where it is converges in last analysis to geometry of distorted rombic coordination. / Neste trabalho sintetizou-se e determinou-se a estrutura cristalina/ molecular de dois pré-ligantes triazenos simétricos: 1,3−bis−(4−acetilamidofenil)triazeno H3CC(O)NHC6H4NNNC6H4NH(O)CCH3] (1) e o 1,3−bis−(4−etóxicarbonilfenil)triazeno [H5C2OC(O)C6H4NNNC6H4C(O)OC2H5] (2), um complexo de cobre(II)(3) e um complexo de Co(III)(4), sendo que os dois complexos envolvem o ligante 1,3-bis(4-metoxicarbonilfenil)triazenido previamente desprotonado. Também apresentou-se a síntese do referido pré-ligante. O composto [H3CC(O)NHC6H4NNNC6H4NH(O)CCH3] (1) cristaliza no sistema monoclínico, grupo espacial C2/c, com parâmetros de cela a=16,0434(8)Å, b=13,0914(6)Å, c=13,0914(6)Å, β = 91,595(2)°, V=3207,2(3)Å 3 ; Z=8. O refinamento dessa estrutura convergiu para os índices de discordância R1=0,0707e wR2=0,1621. O composto [H5C2OC(O)C6H4NNNC6H4C(O)OC2H5] (2) cristaliza no sistema triclínico, grupo espacial P(-1), com parâmetros de cela a=7,65300(10) Å, b=13,4633(2) Å, c=18,0173(3) Å, α= 74,6550(10)°, β= 82,3950(10)° , у = 79,0350(10)°, 1748,5(14) Å 3 ; Z=4. O refinamento dessa estrutura convergiu para os índices de discordância R1=0,1299 e wR2=0,1708. O complexo {Cu[H3COC(O)C6H4NNNC6H4C(O)OCH3]2[(CH3)2N]2} (3) cristaliza no sistema triclínico, grupo espacial P(-1) com parâmetros de cela a=7,91600(10)Å, b=9,1596(2)Å, c=13,4476(2)Å, α=105,4130(10)°, β=96,6370(10)°, у=96,1510(10)°, V=923,96(3)Å3; Z=2. O refinamento dessa estrutura convergiu aos seguintes índices de discordância R1 = 0,0433, wR2 = 0,1293. A esfera de coordenação do íon cobre(II) é formada por dois ligantes triazenos desprotonados e duas moléculas de dimetilamina. O efeito característico da distorção de Jahn-Teller expande a geometria de coordenação do íon Cu(II) para octaédrica distorcida axialmente. O complexo [Co[H3COC(O)C6H4NNNC6H4C(O)OCH3]3} (4) cristaliza no sistema monoclínico, grupo espacial C2/c, com parâmetros de cela a=13,4346(7) Å, b=29,5701(17) Å, c=13,8951(7) Å, β= 107,274(2)°, V= 5271,0(5) Å3; Z=4. O refinamento dessa estrutura convergiu para os seguintes índices de discordância R1=0,1081e wR2=0,2278. A estrutura deste complexo apresenta três ligantes triazenidos bidentados. A geometria de coordenação do íon Co3+ é octaédrica, ela é distorcida conferindo uma assimetria local para a molécula, onde esta converge em última análise para uma geometria de coordenação rômbica distorcida.
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Estudo da autoxidação dos complexos de Cu(II), Ni(II) e Co(II)/tetraglicina induzida por S(IV) / Study of the autoxidation of the complexes of Cu (II), Ni (II) and Co (II)/tetraglycine induced by S(IV)

Sebastian, Maria Vespertina Alipazaga 19 September 2003 (has links)
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.

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