Single-Molecule Magnets (SMMs) are discrete molecules that exhibit slow relaxation of magnetization. Unlike conventional magnets that rely on the long range magnetic ordering in the form of domains, these molecules act as magnets independently, that is without the influence of neighbouring molecules. SMMs have intrigued physicists and chemists alike for over twenty years with their potential future applications in data storage quantum computing, and with this communal interest there has been significant collaboration between the two fields of research. SMMs have brought forth an opportunity for coordination chemists to muster their creativity and synthetic expertise in the rational design and development of these magnetic materials. From these new and fascinating compounds, both experimental and theoretical physicists have sought to develop and refine our understanding of the aspects of these molecular magnets in order to improve their performance at higher temperatures. In this work, new topologies for lanthanide complexes are explored using a novel Schiff base ligand. The magnetic properties of dinuclear, tetranuclear and octanuclear lanthanide complexes are discussed and correlated to their structural properties. The rational design of tetrazine-based Schiff base ligands for magnetic studies is also discussed in hopes of developing high performance SMMs.

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No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) DISSERTAÇÃO Thaís Meira Menezes.pdf: 5590290 bytes, checksum: 6516515f3f28c707bbffd79ee5b3e400 (MD5) Previous issue date: 2017-03-15 / CNPq / Para o desenho de drogas com maior compatibilidade com o sítio de ligação é extremamente importante ter conhecimento do alvo molecular a que se destina o fármaco e da sua maneira de interação, ou seja, é preciso estudar a região onde será feita a conexão com o ligante e o mecanismo da reação. A ampla gama de aplicações para compostos orgânicos derivados de base de Schiff na industria química estende-se desde catalisadores, estabilizadores, intermediário de síntese e corantes. No contexto biológico, estes compostos tem sido empregado devido as suas atividade contra bacterias, fungos, virus, inflamação e neoplasias. Esta classe de moléculas apresentam relevante flexibilidade sintética e apresentam alta seletividade e sensibilidade em relação ao átomo de uma metaloenzima. Diante da relevância destes compostos no contexto biológico foram sintetizados e caracterizados nessa dissertação alguns derivados de base de Schiff. Visando estudar a biodisponibilidade do ponto de vista farmacocinético, estes compostos foram sujeitos a estudos de interação com a proteína BSA, através do mapeamento e monitoramento das mudanças das linhas de RMN frente a titulação com a proteína e os constantes de ligação Kd foram determinadas. Os compostos obtidos foram sujeito a estudos de interação teorico-experimental com a proteína tirosinase que esta envolvida com a mela-nogênese e um marcador neoplásico altamente relevante. A partir do estudo realizado, infere-se que os compostos devidamente sintetizados e caracterizados apresentaram moderada interação com a BSA, forte interação com íons cobre, indicando uma possível coordenação dos compostos com o metal, além da forte interação da NW-F e AMTAC 02 com a enzima tirosinase. Finalmente estudos de inibição de atividade enzimatica foram conduzidos com o composto acridínico AMTAC01 e os resultados mostraram que este composto inibe a proteína com valores de dose resposta IC50 de 8,8.10−8, mesma ordem de grandeza que o inibidor comercial ácido kójico, o que qualifica o composto AM-TAC01 como um potente inibidor da enzima tirosinase. / For the design of drugs with greater compatibility with the binding site, it is extremely important to the molecular target for which the drug is intended and its mode of interaction, that is, it is necessary to study the region where the connection with the ligand and the mechanism of the dog. The wide range of applications for organic compounds derived from Schiff base in the chemistry ranges from catalysts, stabilizers, synthesis intermediates and colorants. At the biological context, these compounds have been employed due to their activity against bacteria, fungi, viruses, inflammation and neoplasms. This class of molecules presents significant flexibility synthetic and have high selectivity and sensitivity to the atom of a metalloenzyme. In view of the relevance of these compounds in the biological context were synthesized and characterized in this dissertation some Schiff base derivatives. Aiming to study the bioavailability of the from a pharmacokinetic perspective, these compounds were subjected to interaction studies with the BSA protein, through the mapping and monitoring of the changes of the NMR lines against titration with the protein and the Kd binding constants were determined. The obtained compounds were subjected to studies of the theoretical-experimental in-teraction with the protein tyrosinase that is involved with the melanogenesis and a highly relevant neoplastic marker. Based on the study, it is inferred that The duly synthesized and characterized compounds presented moderate interaction with BSA, strong interaction with copper ions, indicating a possible coordination of the compounds with the As well as the strong interaction of NW-F and AMTAC 02 with the enzyme tyrosinase. Finally, studies of Inhibition of enzyme activity were conducted with the acridine compound AMTAC01 and the results showed that this compound inhibits the protein with IC 50 dose response values of 8.8.10-8, same order of magnitude as the kojic acid commercial inhibitor, which qualifies the compound AMTAC 01 as a potent inhibitor of the enzyme tyrosinase.

Submitted by Renata Lopes (renatasil82@gmail.com) on 2017-05-10T13:20:15Z No. of bitstreams: 1 guilhermealvespereira.pdf: 4360025 bytes, checksum: eb64a09c2496faa0f384738a80c8b7c9 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-05-17T15:06:50Z (GMT) No. of bitstreams: 1 guilhermealvespereira.pdf: 4360025 bytes, checksum: eb64a09c2496faa0f384738a80c8b7c9 (MD5) / Made available in DSpace on 2017-05-17T15:06:50Z (GMT). No. of bitstreams: 1 guilhermealvespereira.pdf: 4360025 bytes, checksum: eb64a09c2496faa0f384738a80c8b7c9 (MD5) Previous issue date: 2011-08-19 / Os metais, bem como seus compostos, têm sido utilizados na medicina há mais de 5000 anos. Atualmente há vários fármacos que contém, como centro ativo, um íon metálico. Particularmente, os compostos contendo os íons metálicos Ag(I), Au(I) e Au(III) têm demonstrado bons resultados no tratamento e no combate a alguns tipos de enfermidades. Estes compostos possuem atividade biológica contra alguns tipos de vírus e bactérias, por exemplo, contra o vírus HIV, plasmodium falciparium, protozoário parasita causador da malária, e contra a M.tuberculosis, bactéria causadora da tuberculose. Também, os compostos de Au(I) e Au(III), têm sido usados no tratamento dos sintomas da artrite reumatóide e do câncer, respectivamente. Bases de Schiff estão entre os compostos orgânicos mais amplamente estudados e utilizados na pesquisa de novos produtos e fármacos, em função de sua facilidade de síntese e versatilidade de suas propriedades estéricas e eletrônicas. Muitos compostos descritos na literatura estão relacionados complexos metálicos com ligantes deste tipo, pois, além de apresentar grande afinidade para complexar aos íons metálicos Ag(I), Au(I) e Au(III), têm apresentado uma gama de atividades biológicas, incluindo, antifúngica, anti-bacteriana, anti-malárica, antiproliferativa, propriedades anti-inflamatórias, anti-virais e anti-piréticas. O objetivo deste projeto é sintetizar, caracterizar e estudar as propriedades físico-químicas de complexos de Ag(I) e Au(I) com bases de Schiff e estudar, posteriormente, suas atividades biológicas. Os ligantes foram sintetizados a partir da reação de condensação de aminas (2-aminotiofenol, 2-aminofenol e ácido 2-aminobenzóico) com o 2-carboxi-aldeídotiofeno. O ligante BTT foi sintetizado empregando-se a técnica de reação em forno de microondas, utilizando sílicagel como suporte e livre de solventes. Os complexos foram sintetizados adicionando-se aos ligantes o respectivo sal do íon metálico. Os ligantes IminaOH, BTT, IminaSH e IminaCOOH, foram caracterizados por análise elementar, espectroscopia vibracional na região do infravermelho, espectroscopia eletrônica na região do ultravioleta visível e ressonância magnética nuclear. O ligante IminaOH teve sua estrutura cristalina determinada e refinada por técnica de análise de difração de raios X. Com base nos resultados obtidos, foram propostas as seguintes fórmulas moleculares: C11H9NOS, para a IminaOH, C11H7NS2, para o BTT e C12H9NO2S, para a IminaCOOH. Os complexos obtidos foram caracterizados por um conjunto de técnicas analíticas e espectroscópicas e, a partir desses dados coletados, as seguintes fórmulas moleculares foram propostas: [Ag(C11H7NS2)2NO3], para o complexo do ligante BTT com o íon metálico Ag(I), no qual a proporção metal/ligante é de 1:2, nomeado de AgBTT, [Au(C11H7NS2)Cl], para o complexo com Au(I), intitulado AuBTT, com proporção 1:1 metal/ligante e [Ag(C12H8NO2S)NO3]. H2O, para o complexo de prata com o ligante IminaCOOH, chamado de AgIminaCOOH, em que sugere-se a proporção de um íon metálico Ag(I) para um ligante IminaCOOH e meia molécula de H2O, sendo este um complexo hemi-hidratado. O ligante BTT, bem como seus complexos com ouro e prata, foram testados contra bactérias do tipo M.tuberculosis e demonstraram certa atividade. O ligante BTT apresentou CIM de 230 µM, enquanto os complexos AgBTT e AuBTT, apresentaram CIM de 20,7 e 34,7 µM, respectivamente, sendo os valores obtidos para o complexo com prata comparáveis a valores de CIM para a sulfadiazina de prata, composto utilizado como antibacteriano. Nota-se também a sinergia existente entre o ligante BTT e os íons metálicos. / The metals and their compounds have been used in medicine for over 5000 years. Currently there are several drugs containing as active center, a metal ion. Particularly, the compounds containing the metal ions Ag (I), Au (I) and Au (III) have shown good results in treatment and to fight certain types of diseases. These compounds have biological activity against some viruses and bacteria, for example, against the HIV virus, plasmodium falciparum, which causes malaria, and against M.tuberculosis that causes tuberculosis. Also, the compounds of Au (I) and Au (III) have been used to treat the symptoms of rheumatoid arthritis and cancer, respectively. Schiff bases are among the compounds most widely studied and used in research of new products and drugs, due to their easy of synthesis and versatility of their steric and electronic properties. Many compounds described in the literature are related metal complexes with ligands of this type, because, besides having great affinity for complexing the metal ions Ag (I), Au (I) and Au (III), have shown a range of biological activities, including, antifungal, anti-bacterial, anti-malarial, antiproliferative, anti-inflammatory, anti-viral and anti-antipyretic properties. The objective of this project is to synthesize, characterize and study the physicochemical properties of complexes of Ag (I) and Au (I) with Schiff bases and study later, their biological activities. The ligands were synthesized from the condensation reaction of amine (2aminotiofenol, 2-aminophenol and 2-aminobenzoic acid) with 2-carboxy-thiophene aldehyde. The BTT ligand was synthesized employing the reaction technique in a microwave oven, using silica gel as a support and solvent-free. The compounds were synthesized by adding ligands to their metal ion salt. The ligands IminaOH, BTT and IminaCOOH, were characterized by elemental analysis, vibrational, electronic and nuclear magnetic resonance spectroscopies. The ligand IminaOH had its crystal structure determined and refined by analysis technique X-ray diffraction. Based on the results obtained, we propose the following molecular formulas: C11H9NOS, for IminaOH, C11H7NS2 for BTT and C12H9NO2S, for IminaCOOH. Abstract Dissertação de Mestrado Guilherme Alves Pereira The complexes were characterized by a set of analytical and spectroscopic techniques, and data collected from these, the following molecular formulas have been proposed: [Ag(C11H7NS2)2NO3] for the complex of the ligand BTT with metal ion Ag (I) in which the ratio metal / ligand is 1:2, named AgBTT, [Au (C11H7NS2) Cl] for the complex with Au (I), entitled AuBTT, with a ratio of 1:1 metal / ligand and [Ag ( C12H8NO2S) NO3] .1/2H2O for the silver complex with the ligand IminaCOOH, called AgIminaCOOH, suggests that the proportion of 1:1:1/2 metal ion Ag (I):IminaCOOH:H2O. The ligand BTT, as well as their complexes with gold and silver, were tested against bacteria such M.tuberculosis and they demonstrated some activity. That ligand had a MIC values of 230 µM, while the complexes AgBTT and AuBTT showed MIC values of 20.7 and 34.7 µM, respectively, the MIC value obtained for the silver complex is comparable to silver sulfadiazine, used as an antibacterial compound. Note also the synergy between the ligand BTT and metal ions.

This thesis describes the synthesis, characterization and magnetic investigation of homometallic lanthanide complexes based on two different o-vanillin-derived Schiff base ligands: H2ovph and H2ovgrd. The studies were performed using single crystal X-ray diffractometry, Powder XRD and SQUID magnetometry. Chapter 2 focuses on dinuclear systems 1-8 coordinated to the ligand H2ovph and presents their structural and magnetic properties, mainly with respect to their intramolecular interactions. Chapter 3 describes two hexanuclear systems, 9 (DyIII) and 10 (GdIII), with trigonal prism-assembled core structures. A structural comparison to other similar complexes in the literature is performed. A series of dinuclear complexes, 11-15, based on the ligand H2ovgrd are described in Chapter 4, focusing on the synthetic strategy, crystal structures and magnetism. The presence of the lanthanide contraction is evident in this system of complexes and is consistent with the intrinsic lanthanide contraction property.

Thesis (M.Sc.(Chemistry)) -- University of Limpopo, 2016 / Imidazolyl-salicylaldemine Schiff base ligands were prepared by the condensation of different substituted salicylaldehydes with histamine dihydrochloride: 2,4-di-tert-butyl-6-{[2-(1H-imidazol-4-yl)-ethylimino]-methyl}-phenol L1; 4-methoxy-6-{[2-(1H-imidazol-4-yl)-ethylimino]-methyl}-phenol L2; 2-ethoxy-6-{[2-(1H-imidazol-4-yl)-ethylimino]-methyl]-phenol L3; 2-methyl-6-{[2-(1H-imidazol-4-yl)-ethylimino]-methyl}-phenol L4; 3-methyl-6-{[2-(1H-imidazol-4-yl)-ethylimino]-methyl}-phenol L5; 4-methyl-6-{[2-(1H-imidazol-4-yl)-ethylimino]-methyl}-phenol L6; 5-methyl-6-{[2-(1H-imidazol-4-yl)-ethylimino]-methyl}-phenol L7; 2-tert-butyl-6-{[2-(1H-imidazol-4-yl)-ethylimino]-methyl}-phenol L8; 3-methoxy-6-{[2-(1H-imidazol-4-yl)-ethylimino]-methyl}-phenol L9; 4-tert-butyl-6-{[2-(1H-imidazol-4-yl)-ethylimino]-methyl}-phenol L10. The ligands were characterised by 1H, 13C and 15N NMR, FT-IR, UV-vis spectroscopic methods, mass spectroscopy and elemental analysis where possible. Reactions of L1-L9 with MnCl2 and CuCl2 yielded complexes C1–C18 all in a ratio of (1:1). C1 – C18 here, i.e. C18 2-methyl-6-{[2-(1H-imidazol-4-yl)-ethylimino]-methyl}-phenol Cu(II) chloride. The complexes that are paramagnetic were mainly characterised by FT-IR spectroscopy, UV-vis spectroscopy, mass spectroscopy and elemental analysis. Reaction of L9 with ZnCl2 yielded 2-methyl-6-{[2-(1H-imidazol-4-yl)-ethylimino]-methyl}-phenol Zn(II) chloride, C19 which is diamagnetic and was characterised by 1H, 13C NMR spectroscopy Mass spectroscopy and Elemental analysis. Condensation of o-phenylenediamine and glyoxylic acid yielded 2-quinoxalinone Q1, reaction of 2-quinoxalinone and benzenesulfonyl chloride yielded 2-benzenesulfonyloxyquinoxaline Q2, and the reaction of 2-benzenesulfonyloxyquinoxaline with ethynyltrimethylsilane yielded 2-ethynyltrimethylsilanequinoxaline Q3. Quinoxaline and its preceding starting compounds were characterised by 1H, 13C NMR spectroscopy. Attempts to cross couple Schiff base complex C19 and Q3 via Sonogashira cross coupling mechanism method was not successful after two attempts from following two different reaction routes and conditions. The trans-metalation route yielded quinoxaline derivative QA in good yield after the reaction of Q3 with ZnCl2 and, C19 in the presence of Et2NH which were characterised by NMR (1H, 13C and HMBC), Mass spectroscopy (HRMS) and Elemental analysis. iv These reactions showed hydroamination instead of coordination in yield of (90%) using ZnCl2 as catalyst and 60% using C19 as catalyst. Biological activity studies were done by quantitative antibacterial activity by assay of minimum inhibition concentration (MIC). Bacterial cells used as pathogenic microorganisms were gram negative: Escherichia coli and Pseudomonas aeruginosa, gram positive: Staphylococcus aureus and Enterococcus faecalis. Compound used for testing : L9, C19, C18, C9, Q3 and QA. All compounds were found to be active against bacterial cells of E. coli and E. faecalis with a minimum inhibition concentration of 0.004 mg/ml average and total activity of 500 mg/ml average. For all compounds used for testing bacterial activity against cells of P. aeruginosa and S. aureus, the lowest concentration was 0.063 mg/ml average and total activity of 266 mg/ml average for C18. P. aeruginosa and S. aureus were found to be less active compared to bioactive standards used for E. coli and E. faecalis.

Thesis (M.Sc. (Chemistry)) -- University of Limpopo, 2016 / Imidazolyl-salicylaldemine Schiff base ligands were prepared by the condensation of different substituted salicylaldehydes with histamine dihydrochloride: 2,4-di-tert-butyl-6-{[2-(1H-imidazol-4-yl)-ethylimino]-methyl}-phenol L1; 4-methoxy-6-{[2-(1H-imidazol-4-yl)-ethylimino]-methyl}-phenol L2; 2-ethoxy-6-{[2-(1H-imidazol-4-yl)-ethylimino]-methyl]-phenol L3; 2-methyl-6-{[2-(1H-imidazol-4-yl)-ethylimino]-methyl}-phenol L4; 3-methyl-6-{[2-(1H-imidazol-4-yl)-ethylimino]-methyl}-phenol L5; 4-methyl-6-{[2-(1H-imidazol-4-yl)-ethylimino]-methyl}-phenol L6; 5-methyl-6-{[2-(1H-imidazol-4-yl)-ethylimino]-methyl}-phenol L7; 2-tert-butyl-6-{[2-(1H-imidazol-4-yl)-ethylimino]-methyl}-phenol L8; 3-methoxy-6-{[2-(1H-imidazol-4-yl)-ethylimino]-methyl}-phenol L9; 4-tert-butyl-6-{[2-(1H-imidazol-4-yl)-ethylimino]-methyl}-phenol L10. The ligands were characterised by 1H, 13C and 15N NMR, FT-IR, UV-vis spectroscopic methods, mass spectroscopy and elemental analysis where possible. Reactions of L1-L9 with MnCl2 and CuCl2 yielded complexes C1–C18 all in a ratio of (1:1). C1 – C18 here, i.e. C18 2-methyl-6-{[2-(1H-imidazol-4-yl)-ethylimino]-methyl}-phenol Cu(II) chloride. The complexes that are paramagnetic were mainly characterised by FT-IR spectroscopy, UV-vis spectroscopy, mass spectroscopy and elemental analysis. Reaction of L9 with ZnCl2 yielded 2-methyl-6-{[2-(1H-imidazol-4-yl)-ethylimino]-methyl}-phenol Zn(II) chloride, C19 which is diamagnetic and was characterised by 1H, 13C NMR spectroscopy Mass spectroscopy and Elemental analysis. Condensation of o-phenylenediamine and glyoxylic acid yielded 2-quinoxalinone Q1, reaction of 2-quinoxalinone and benzenesulfonyl chloride yielded 2-benzenesulfonyloxyquinoxaline Q2, and the reaction of 2-benzenesulfonyloxyquinoxaline with ethynyltrimethylsilane yielded 2-ethynyltrimethylsilanequinoxaline Q3. Quinoxaline and its preceding starting compounds were characterised by 1H, 13C NMR spectroscopy. Attempts to cross couple Schiff base complex C19 and Q3 via Sonogashira cross coupling mechanism method was not successful after two attempts from following two different reaction routes and conditions. The trans-metalation route yielded quinoxaline derivative QA in good yield after the reaction of Q3 with ZnCl2 and, C19 in the presence of Et2NH which were characterised by NMR (1H, 13C and HMBC), Mass spectroscopy (HRMS) and Elemental analysis. iv These reactions showed hydroamination instead of coordination in yield of (90%) using ZnCl2 as catalyst and 60% using C19 as catalyst. Biological activity studies were done by quantitative antibacterial activity by assay of minimum inhibition concentration (MIC). Bacterial cells used as pathogenic microorganisms were gram negative: Escherichia coli and Pseudomonas aeruginosa, gram positive: Staphylococcus aureus and Enterococcus faecalis. Compound used for testing : L9, C19, C18, C9, Q3 and QA. All compounds were found to be active against bacterial cells of E. coli and E. faecalis with a minimum inhibition concentration of 0.004 mg/ml average and total activity of 500 mg/ml average. For all compounds used for testing bacterial activity against cells of P. aeruginosa and S. aureus, the lowest concentration was 0.063 mg/ml average and total activity of 266 mg/ml average for C18. P. aeruginosa and S. aureus were found to be less active compared to bioactive standards used for E. coli and E. faecalis.

Orientador: Sergio Antonio Marques de Lima / Coorientador: Ana Maria Pires / Banca: Valdemiro Pereira de Carvalho Júnior / Banca: Andrea Simone Stucchi de Camargo Alvarez Bernardez / Resumo: A sílica apresenta características que a torna uma boa matriz hospedeira de moléculas e biomoléculas, fazendo dela um material promissor para inúmeras aplicações, destacando-se catálise, liberação controlada de fármacos, desenvolvimento de biomarcadores e demais aplicações. Um biomarcador à base de sílica deve possuir um composto luminescente ligado covalentemente à superfície da matriz. Sendo assim, complexos com íons lantanídeos e irídio são promissores, pois apresentam forte luminescência no visível, e desta forma são ótimos candidatos para o uso como sondas luminescentes. O presente trabalho tem como foco principal a síntese, caracterização e estudo das propriedades de nanopartículas de sílica funcionalizadas na superfície com compostos luminescentes. Esses novos luminóforos à base de nanopartículas de sílica foram preparados pelo método sol-gel e através da ancoragem de complexos de Eu3+ e Ir3+ à superfície da matriz inorgânica, utilizando ligantes do tipo Base de Schiff. Também foram sintetizados ligantes imínicos não sililados, sililados e ancorados à sílica; três complexos [Eu(salba)3], [Eu(salen)2] e [Ir(ppy)2(salba)]; e três conjugados [Eu(salpaSi)(H2O)x]-SiO2, [Eu(dbm)3(salpaSi)]-SiO2 e [Ir(ppy)2(salpaSi)]-SiO2. Todos tiveram sua formação comprovada pela análise via Espectroscopia Vibracional na região do Infravermelho. As partículas de sílica funcionalizadas foram analisadas por microscopia eletrônica de varredura e a morfologia avaliada, sendo observado partículas esferoidais e com tamanho na faixa de 200-250 nm. O íon Eu3+ nos complexos foi sensibilizado pelos ligantes utilizados, e o uso do Ir3+ causou aumento na intensidade de emissão por parte dos ligantes, causado pelo forte acoplamento spin-orbital / Abstract: Silica is a versatile material and has specific properties that make it a good host for molecules and biomolecules suggesting promising applications such as in catalysis, drug controlled release, biomarkers, and so on. To be used as a biomarker it requires a luminescent molecule covalently linked to its surface. For this application, lanthanide complexes are very promising since they exhibit intense multicolor emissions. Also, some transition metal complexes exhibit good luminescent properties, that makes them good candidates for use as luminescent probes in biological media. The main scope of this work is the synthesis, characterization and evaluation of luminescent functionalized silica nanoparticles. These new phosphors based on silica nanoparticles were obtained by sol-gel method, followed by covalent bounding with Eu3+-complexes or Ir3+-complexes, through a Schiff base ligand type. We also describe the synthesis and characterization of two Schiff base ligands: Salba and SalpaSi. The last one was attached to the silica nanoparticles surface to form SalpaSi- SiO2. Three complexes {[Eu(salba)3], [Eu(salen)2] and [Ir(ppy)2(salba)]} and three conjugates {[Eu(salpaSi)(H2O)x]-SiO2, [Eu(dbm)3(salpaSi)]-SiO2 and [Ir(ppy)2(salpaSi)]-SiO2} were prepared. All compounds were analyzed by Infrared Spectroscopy, confirming their synthesis. Functionalized silica nanoparticles were analyzed by Scanning Electronic Microscopy, from where we could observe these particles are spheroidal shaped with diameter in the range 200-250 nm. The Eu3+ ion in the complexes was sensitized by the ligands emitting a reddish color, while the use of Ir3+ caused an increase in the emission intensity of the ligand, caused by strong spin-orbital coupling / Mestre

Orientador: Beatriz Eleutério Goi / Coorientador: Valdemiro Pereira de Carvalho Júnior / Banca: Pedro Ivo da Silva Maia / Banca: Ana Maria Pires / Resumo: Nas últimas décadas, a polimerização radicalar controlada (CRP) tem se tornado muito importante, pois permite a síntese de macromoléculas de arquiteturas específicas com um controle sobre as propriedades químicas e físicas. Sendo assim, este trabalho apresenta a síntese de novos complexos de Mn(II) e Fe(II) coordenados à ligantes bases de Schiff bidentados, que são resultantes da condensação do salicilaldeído com as seguintes cicloalquilaminas: (1) Ciclopentilamina, (2) Cicloexilamina, (3) Cicloeptilamina e (4) Ciclooctilamina, de forma que estes possam ser utilizados como mediadores da polimerização radicalar mediada por organometálicos. Os ligantes foram caracterizados pelas seguintes técnicas: espectroscopia de ressonância magnética nuclear de hidrogênio (RMN de 1H), espectroscopia de absorção na região do ultravioleta-visível (UV-Vis) e espectroscopia vibracional na região do infravermelho (FTIR). Já os complexos de Mn(II) e Fe(II) foram caracterizados pelas técnicas de FTIR, UV-Vis, voltametria cíclica (VC) e ponto de fusão (p.f.). Os estudos cinéticos de polimerização foram realizados para os complexos de manganês e ferro. O complexo [MnIIbis(N-Salicilideno-Ciclopentilamina)], Mn(L1)2, apresentou um melhor controle na polimerização do acetato de vinila com menores valores de polidispersidade e a curva de massa molecular (Mn) mais próxima aos valores da curva teórica. Já os complexos de ferro mediadores apresentaram um comportamento mais similar, não havendo muita... / Abstract: In the last decades, controlled radical polymerization (CRP) has become very important, since it facilitates the synthesis of macromolecules of specific architectures with excellent control over the chemical and physical properties. Thus, this work presents the synthesis of new Mn(II) and Fe(II) complexes coordinated with the bidentate Schiff bases ligands, which are the result of the condensation of salicylaldehyde with cycloalkylamines: (1) cyclopentylamine, (2) cyclohexylamine, (3) cycloheptylamine and (4) cyclooctylamine, so that they can be used as mediators of radical polymerization mediated by organometallic (OMRP). The ligands synthesized were characterized by proton nuclear magnetic resonance (1H-NMR) spectroscopy, ultraviolet-visible (UV-Vis) absorption spectroscopy and Fourier-transform infrared spectroscopy (FTIR) techniques. The synthesized Mn(II) and Fe(II) complexes were studied by FTIR, UV-Vis, cyclic voltammetry (CV) and melting point (m.p.). Kinetic polymerization studies were performed for the manganese and iron complexes. The [MnIIbis (N-Salicylidene-Cyclopentylamine)], Mn(L1)2, complex showed a better control in the polymerization of vinyl acetate with lower values of polydispersity and the molecular mass curve (Mn) closer to the values of the theoretical curve. However, the iron mediator complexes presented a more similar behavior, not having much difference in the kinetic curves / Mestre

No description available.

Ligands prepared from various combinations of aldehydes and ketones with the appropriate aminealcohol were complexed with cupric acetate monohydrate. The complexes with O,NO or N,N,O donor atoms were synthesized to study the influences of the ligand on molecular structure, spin-spin interaction, and on the value of the exchange integral. The magnetic data indicated that of the eight Cu(II) complexes discussed, two behaved differently from known analogous compounds. Cu (benzoylacetone :ethanolamine) was compared to Cu(acac:ethanolamine), and Cu(pyrr:oaminophenol) was compared to Cu(acac:o-aminophenol). Each pair of complexes was postulated to have the same molecular structure. The synthesis and characterization of Mn(pyrr:oaminophenol) 2H2 is also discussed. The following physical data were collected and discussed: elemental analysis, melting point, molecular weight, infrared spectra, electronic spectra, and magnetic susceptibility.