This thesis describes the design, synthesis and reactivity of bimetallic complexes of doubly-pillared Schiff-base calixpyrrole ligands. Chapter One introduces the oxygen reduction reaction in light of the global energy scenario at present and in the future. Compounds and materials known to catalyse this reaction are discussed, with particular focus on transition metal complexes of pyrrole-containing macrocycles and the ability of these compounds to act as catalysts in redox reactions. Chapter Two describes the design and synthesis of several of the macrocyclic ligands developed during this project. The wide range of metals and geometries supported by one of the ligands, H4L, are outlined and include complexes of alkali-metals (Li, K), a rare earth metal (Mg), transition metals (Pd, Fe) and an actinide (UO2 2+). Chapter Three presents the use of [Co2(L)] for the reduction of dioxygen to water. The redox behaviour of the complex and its ability to reversibly bind oxygen were evaluated. The catalytic activity of [Co2(L)] was investigated in solution by UV-Vis spectrophotometry and electrochemically by rotating ring-disk electrochemistry. In Chapter Four, the ability of [Zn2(L)] to bind anions is described. Isothermal microcalorimetry, NMR, UV-Visible spectrophotometry, and fluorophotometry were used to study the de-aggregation of the anion free complex and the subsequent anion binding event. The stability of the complexes was estimated by DFT calculations. Chapter Five outlines the synthesis of complexes of L for other transition metals relevant to small molecule activation. Chapter Six contains a conclusion and suggestions on further investigations to carry out. Chapter Seven presents the full experimental details and analytical data for this work.

Silver(I) complexes of type LnAgX (X = organic ligand, such as carboxylates, dicarboxylates, Schiff-base; L = Lewis-bases, e. g. PnBu3, P(OMe)3, P(OEt)3; n = 1, 2, 3) have been synthesized and characterized with respect to their suitability for the Chemical Vapour Deposition (CVD) of silver thin films. For some of these compounds single crystal could be obtained. Their solid-state structure was determined by single crystal X-ray diffraction. The volatility, thermal stability, and gas phase decomposition mechanism of selected compounds were studied using temperature-programmed and in-situ mass spectrometry. CVD experiments were performed according to the results of the gas phase analysis. Silver films could be grown by using a cold-wall CVD reactor. The morphology of the latter films was determined. / Silber(I) Komplexe LnAgX (X = organische Ligand, Z. B. Carboxylate, Dicarboxylate, Schiff Base; L = Lewis-Base, Z. B. PnBu3, P(OMe)3, P(OEt)3; n = 1, 2, 3) wurden Bezug auf ihre Eignung für die chemische Gasphasenabscheidung von Silberfilmen synthetisiert und charakterisiert. Von einigen dieser Verbindung konnten Einkristalle erhalten werden. Der Bau dieser Verbindungen wurde mittels Röntgeneinkristallographie ermittelt. Ausgewählten Verbindungen wurden mit Temperatur-programmierter und in-situ Massenspektrometrie analysiert. Gasphasenabscheidungs- mechanismen für einige Prekursoren sind vorgestellt. CVD-Abscheidungsexperimente wurden entsprechend den Ergebnissen der Gasphaseanalyse durchgeführt. Silber Schichten konnten mit einen Kaltwand CVD-Reaktor erzeugt werden, deren Oberflächenmorphologie wurde untersucht.

Disertacijoje nagrinėjamas galimas aplinkos poveikis organinių molekulių elektroninių būsenų savybėms. Tam tikslui yra naudojami kompiuterizuotieji kvantinės mechanikos metodai, kuriais remiantis nagrinėjamos įvairių molekulių savybės. Ištirtos 2-(N-metil-α-iminoethyl)-fenol ir N-triphenylmethylsalicylidene imine molekelulių, esančių poliniame tirpiklyje, struktūros pagrindinėje ir sužadintose elektroninėse būsenose. Pirmą kartą parodyta, kad, norint gauti teisingą kokybinį ir artimą kiekybiniam vidujmolekulinės protono pernašos potencinės energijos paviršių, būtina atsižvelgti į polinių tirpiklio molekulių kuriamą vandenilinių ryšių tinklą bei į nulinių svyravimų energijas. Pastarieji ir nulemia protono pernašos vyksmo kryptį bei efektyvumą. Parodyta, kad anilų klasės molekulių konformerų susiformavimas priklauso nuo tirpiklio poliškumo, o jų susidarymas savo ruožtu konkuruoja su klasterių iš tirpiklio molekulių susiformavimo galimybėmis. Pirmą kartą parodyta, kad dipolinio momento vertė bakteriorodopsine yra nulemta membranos paviršiuose esančių radikalų. Pademonstruota, kad stilbazolio molekulė deformuojasi ir sudaro naujus konformerus (pademonstruota dviejų formų atsiradimo galimybė) tik esant molekulėms tirpalo apsuptyje. Šis rezultatas paaiškino eksperimente stebimus skirtuminių spektrinių pokyčių evoliucijos prigimtį. Apskaičiuotos ir išanalizuotos karotinoidų - luteino, violaksantino ir zeaksantino molekulių - žemiausios sužadintos elektroninės būsenos. Parodyta... [toliau žr. visą tekstą] / To explore changes caused by the environment on the internal characteristics of an organic molecule is the objective of the thesis. For this purpose we investigate a variety of organic molecules. Using various methods of quantum mechanics calculations possible influence of a polar solvent on the ground and excited states of 2-(N-metil-α-iminoethyl)-fenol and N-triphenylmethylsalicylidene imine is considered. It is shown for the first time that in order to obtain the correct qualitative and quantitative interpretation of possible pathways of the intermolecular proton transfer the hydrogen network of the polar solvent molecules together with the zero point energy have to be taken into consideration. It is also shown that conformational variability of anil-type molecules in polar solvents is competing with clusters formation of solvent molecules. It is shown for the first time that the dipole moment of bacteriorhodopsin is mainly defined by cytoplasmic and extracellular coils on the surfaces of the membrane. It is also demonstrated that the stilbazole molecule experiences the deformation resulting in formation of new conformers (at least two forms are present) in the solvent surrounding. The experimental data of the transient spectroscopy were explained in the basis of these model calculations. The lowest excited states of carotinoids, such as lutein, zeaxanthin and violoxantin are calculated and analyzed. Sensitivity of the excited electronic state on the polar environment is... [to full text]

Disertacijoje nagrinėjamas galimas aplinkos poveikis organinių molekulių elektroninių būsenų savybėms. Tam tikslui yra naudojami kompiuterizuotieji kvantinės mechanikos metodai, kuriais remiantis nagrinėjamos įvairių molekulių savybės. Ištirtos 2-(N-metil-α-iminoethyl)-fenol ir N-triphenylmethylsalicylidene imine molekelulių, esančių poliniame tirpiklyje, struktūros pagrindinėje ir sužadintose elektroninėse būsenose. Pirmą kartą parodyta, kad, norint gauti teisingą kokybinį ir artimą kiekybiniam vidujmolekulinės protono pernašos potencinės energijos paviršių, būtina atsižvelgti į polinių tirpiklio molekulių kuriamą vandenilinių ryšių tinklą bei į nulinių svyravimų energijas. Pastarieji ir nulemia protono pernašos vyksmo kryptį bei efektyvumą. Parodyta, kad anilų klasės molekulių konformerų susiformavimas priklauso nuo tirpiklio poliškumo, o jų susidarymas savo ruožtu konkuruoja su klasterių iš tirpiklio molekulių susiformavimo galimybėmis. Pirmą kartą parodyta, kad dipolinio momento vertė bakteriorodopsine yra nulemta membranos paviršiuose esančių radikalų. Pademonstruota, kad stilbazolio molekulė deformuojasi ir sudaro naujus konformerus (pademonstruota dviejų formų atsiradimo galimybė) tik esant molekulėms tirpalo apsuptyje. Šis rezultatas paaiškino eksperimente stebimus skirtuminių spektrinių pokyčių evoliucijos prigimtį. Apskaičiuotos ir išanalizuotos karotinoidų - luteino, violaksantino ir zeaksantino molekulių - žemiausios sužadintos elektroninės būsenos. Parodyta... [toliau žr. visą tekstą] / To explore changes caused by the environment on the internal characteristics of an organic molecule is the objective of the thesis. For this purpose we investigate a variety of organic molecules. Using various methods of quantum mechanics calculations possible influence of a polar solvent on the ground and excited states of 2-(N-metil-α-iminoethyl)-fenol and N-triphenylmethylsalicylidene imine is considered. It is shown for the first time that in order to obtain the correct qualitative and quantitative interpretation of possible pathways of the intermolecular proton transfer the hydrogen network of the polar solvent molecules together with the zero point energy have to be taken into consideration. It is also shown that conformational variability of anil-type molecules in polar solvents is competing with clusters formation of solvent molecules. It is shown for the first time that the dipole moment of bacteriorhodopsin is mainly defined by cytoplasmic and extracellular coils on the surfaces of the membrane. It is also demonstrated that the stilbazole molecule experiences the deformation resulting in formation of new conformers (at least two forms are present) in the solvent surrounding. The experimental data of the transient spectroscopy were explained in the basis of these model calculations. The lowest excited states of carotinoids, such as lutein, zeaxanthin and violoxantin are calculated and analyzed. Sensitivity of the excited electronic state on the polar environment is... [to full text]

Magister Scientiae - MSc (Chemistry) / This work involves the synthesis of copper telluride-polypropylenimine tetra(5-(2-thienyl) salicylaldimine) (CuTe@PPI) and copper antimonide-polypropylenimine tetra(5-(2-thienyl) salicylaldimine) (CuSb@PPI) core-shell nanoparticles (NPs), using two-pots and one-pot synthesis methods, respectively. Their morphology was studied by X-ray diffraction spectroscopy (XRD), high resolution transmission electron microscopy (HRTEM) and high resolution scanning electron microscopy (HRSEM); while their structures were characterized by Fourier transform infrared spectroscopy (FTIR) and elemental analysis. Photophysical properties of the core-shell NPs were determined from ultraviolet-visible absorption spectroscopy (UV-Vis) and photoluminescence spectroscopy (PL). For core-shell NPs produced via two-pots method only CuTe@PPI exhibited ? ? ?* and n ? ?* which indicate that CuSb@PPI produced via two-pots method was unsuccessfully synthesized. The ? ? ?* and n ? ?* transitions indicate the presence of polypropylenimine tetra(5-(2-thienyl) salicylaldimine) (PPI) on the surface of CuTe NPs and CuSb NPs. FTIR confirmed coordination of PPI on the surface of CuTe NPs and CuSb NPs by showing a shift in wavenumber of C=N group bands from PPI. HR-TEM showed that the CuTe@PPI synthesized via one-pot method have a wide particles sizes distribution with an average particles size of 13.60 nm while for CuTe@PPI synthesized via two-pots it was impossible to determine the particles size due to aggregation. CuSb@PPI synthesized via twopots method and one-pot method has a wide particles sizes distribution with an average size of 7.98 nm and 11.61 nm respectively. The average particles sizes determined by HR-SEM were found to be 35.24 nm (CuTe@PPI two-pots method), 33.90 nm (CuTe@PPI one-pot method), 18.30 nm (CuSb@PPI two-pots method), and 16.18 nm (CuSb@PPI one pot method). / 2021-08-31

Submitted by Maike Costa (maiksebas@gmail.com) on 2016-05-04T14:36:33Z No. of bitstreams: 1 arquivo total.pdf: 1858990 bytes, checksum: 3b9c1c92812cc3daa634b61430ba84d6 (MD5) / Made available in DSpace on 2016-05-04T14:36:33Z (GMT). No. of bitstreams: 1 arquivo total.pdf: 1858990 bytes, checksum: 3b9c1c92812cc3daa634b61430ba84d6 (MD5) Previous issue date: 2014-03-07 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / Recently there have arisen new compounds of Schiff base type synthesized from the condensation of Meldrum's acid (or its derivatives) with a diamine (ethylenediamine or o-phenylenediamine) providing compounds classified as melens or melophens, which are structural analogues to the classical salens and salophens. The melophens have been used as ligands to form metal complexes analogous to salophens aiming its application in biomimetic catalysis. Herein, we describe the voltammetric electrochemical characterization to four ligands (H2melen, H2Cy2melen, H2melophen and H2Cy2melophen) and two complexes (MnII(Cy2melofen) and NiII(melophen)) on aprotic medium (DMF) using glassy carbon electrode work, and Ag|Ag+ (0,1 mol·L-1 TBAP, 10 mmol AgNO3) as reference electrode. The H2melen and H2Cy2melen behaved similarly showing an irreversible one electron reduction process (1e-). The proposed mechanism for those compounds involves a step dimerization. The H2melophen and H2Cy2melophen demonstrated similar behavior showing two reductions and two irreversible oxidations, where one of the processes is adsorption of reactant and product. The MnII(Cy2melophen) complex showed a single quasi-reversible redox process centered on the metal MnIII/MnII, which involves the transfer of one electron. The NiII(melophen) presented four cases, being a quasi-reversible (1e-) and the others irreversible processes involving a total of 5 electrons. All potentials were corrected across the redox couple of ferrocene (Fc/Fc+), and the effect of addition of acids and bases in the medium is discussed. / Recentemente, novos compostos do tipo base de Schiff, análogos estruturais aos clássicos salens e salofens, foram obtidos a partir da condensação do ácido de Meldrum (ou seus derivados) com uma diamina (etilenodiamina ou orto-fenilenodiamina), fornecendo compostos denominados melens ou melofens. Os melofens têm sido utilizados como ligantes a fim de formar complexos metálicos análogos aos salofens, visando sua aplicação em catálise biomimética. Neste trabalho é apresentada a caracterização eletroquímica de quatro ligantes (H2melen, H2Cy2melen, H2melofen e H2Cy2melofen) e dois complexos (MnII(Cy2melofen) e NiII(melofen)) em meio aprótico (DMF), empregando carbono vítreo como eletrodo de trabalho, mediante a aplicação de técnicas voltamétricas. O H2melen e o H2Cy2melen apresentaram comportamentos semelhantes exibindo uma redução irreversível envolvendo um elétron (1e-). O mecanismo proposto para esses compostos envolve uma etapa de dimerização. O H2melofen e o H2Cy2melofen apresentaram comportamentos semelhantes exibindo duas reduções e duas oxidações irreversíveis, onde em um dos processos ocorre adsorção do reagente e do produto. O complexo MnII(Cy2melofen) apresentou um único processo redox quase-reversível centrado no metal MnIII/MnII, o qual envolve 1e-. O NiII(melofen) apresentou quatro processos, sendo um quase-reversível (1e-) e os demais irreversíveis envolvendo um total de 5e-. Todos os potenciais foram corrigidos frente o par redox do ferroceno (Fc/Fc+), e o efeito da adição de ácidos e bases ao meio é discutido.

Made available in DSpace on 2015-05-14T13:21:28Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 3057605 bytes, checksum: 28d023a60720f2efcfba34ac8067319f (MD5) Previous issue date: 2013-07-24 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / We describe here the synthesis and characterization of six compounds derived from Meldrum's acid inspired in the classic salens/salofens systems: four ligands (H2melen, H2Cy2melen, H2melophen, and H2Cy2melophen) and two Mn complexes [MnII(melophen)·1,7H2O and MnII(Cy2melophen)·1,7H2O]. Only H2melofen has been previously described. The ligands were synthesized via the reaction between a 5-methoxymethylene derivative of Meldrum's acid and the diamines ethylenediamine or o-phenylenediamine, resulting in the ligands melens or melofens, respectively, in moderate-to-high yields. The melens and melophens were characterized by 1H and 13C NMR, IR, and ESI-MS. UV-vis studies and thermal analysis (TG/DTA) of this class of compounds were reported here for the first time. Molar absorptivity (ε) for the absorption maxima in EtOH and DMSO were determined. TG/DTA studies were consistent with a two-step process: decomposition of the Meldrum ring (with loss of CO2 and ketone) yields likely a bis-ketene, which is then fully oxidized at high temperatures. The synthesis of new Schiff-base-type coordination compounds ,using Mn(OAc)2·4H2O as a source of Mn led to the isolation of MnII(melofen)·1,7H2O and MnII(Cy2melofen)·1,7H2O in 45% and 47% yield, respectively; all attempts to metallate the melens compounds were unsuccessful. The Mn-melophens proved insoluble in water and of low stability to acidic demetallation. Data of ESI-MS, TG/DTA, conductimetry, FT-IR and UV-vis spectroscopies, cyclic voltammetry and elemental analysis (%Mn) were used to characterize the MnII-melophens and are consistent with the isolation of Mn(II) complexes, in contrast with the Mn(III) complexes of MnIII-salophens. The metallation stabilized Meldrum´s ring thermally, but, once decompose began with loss of CO2 and ketone, the presence of manganese facilitated the combustion of the remaining organic matter. The effect of increasing the Mn(III)/Mn(II) reduction potential for the design of SOD mimics and cytochrome P450 models based on this new class of ligands is discussed. / Descreve-se aqui a síntese e caracterização de seis compostos derivados de ácido de Meldrum inspirados nos clássicos salens/salofens, sendo quatro ligantes (H2melen, H2Cy2melen, H2melofen e H2Cy2melofen) e dois complexos de Mn (MnII(melofen)·1,7H2O e MnII(Cy2melofen)·1,7H2O). Apenas o composto H2melofen não é inédito. Os ligantes foram sintetizados através da reação entre os derivados 5-metoximetilênico do ácido de Meldrum e diaminas etilenodiamina ou o-fenilenodiamina, resultando nos ligantes melens ou melofens, respectivamente, com bons rendimentos, melens (77% e 83%) e melofens (71% e 46%). Os melens e melofens foram caracterizados por RMN de 1H e 13C, IV, e ESI-MS. Estudos de UV-vis e de análise térmica (TG/DTA) dessa classe de compostos foram reportados pela primeira vez. Absortividades molares (ε) dos máximos de absorção em EtOH e DMSO foram determinadas. Os estudos de TG/DTA são consistentes com um processo em duas etapas: a decomposição do anel de Meldrum (com liberação de cetona e CO2) resulta, possivelmente na formação de um bis-ceteno, que é, em seguida, oxidado em elevadas temperaturas. A síntese de novos compostos de coordenação do tipo base de Schiff, usando Mn(OAc)2·4H2O como fonte de Mn, resultou nos complexos MnII(melofen)·1,7H2O e MnII(Cy2melofen)·1,7H2O em rendimentos de 45% e 47%, respectivamente; todas as tentativas de metalação dos melens foram sem sucesso. Os Mn-melophens mostraram-se insolúveis em água e de baixa estabilidade frente à desmetalação ácida. Os dados de ESI-MS, TG/DTA, condutimetria, espectroscopia (UV-vis e IV), voltametria cíclica e análise elementar (%Mn), foram usados na caracterização dos MnII-melofens e são consistentes com o isolamento de complexos de Mn(II), em contraste com os de Mn(III) dos MnIII-salofens. A metalação estabilizou termicamente o anel de Meldrum, mas, uma vez iniciada a decomposição daquele com a perda de CO2 e cetona, a presença do Mn facilitou a combustão da matéria orgânica restante. O efeito do aumento do potencial de redução Mn(III)/Mn(II) para o design de mímicos de SOD e de citocromos P450 à base dessa nova classe de ligantes é discutido.

Due to the system does not recognize equations and formulas the resumo and abstract can be found in the PDF file. / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Devido ao sistema não reconhecer equações e fórmulas o resumo e abstract encontra-se no arquivo em PDF.

La double condensation de la 2-thénoyltrifluoroacétone (TTAH) avec les diamines primaires ne conduit pas aux bases de Schiff symétriques attendues mais dans le cas de l’éthylènediamine (en) à un mélange formé de l’éthylène-bis(trifluoroacétamide) et de la 7-(thiophène-2-yle)-5-(trifluorométhyle)-2,3-dihydro-1H-1,4-diazépine, alors qu’à partir de l’o-phénylènediamine seule la 4-trifluorométhyle-2-(thiophène-2-yle) -1,5-benzodiazépine est isolée. La réaction de condensation entre l’éthylènediamine et un complexe template [M(TTA)2(S)2] (M = Co, Ni, Cu) conduit exclusivement aux complexes octaédriques correspondants [M(TTA)2(en)], dans lesquels l’éthylènediamine est coordonnée au métal. Les coordinats bases de Schiff symétriques [H2N2O2], porteurs des unités 2-thiényles et trifluorométhyles, sont préparés en deux étapes : a) double condensation de l’acétyle thiophène avec l’éthylènediamine pour générer la diimine, puis b) traitement de cette dimine par l’acide trifluoroacétique. Dans les complexes bases de Schiff correspondants de Co(II), Ni(II) et Cu(II), le métal adopte une géométrie plan carré et est coordiné par les atomes d’azote et d’oxygène de l’entité dianionique tétradentate [N2O2]2-. Ces complexes, tout comme leurs homologues où le groupe CF3 a été substitué par l’entité 4-fluorophényle, sont inertes vis-à-vis de l’électropolymérisation. Par contre, la substitution du groupe CF3 par le groupe méthyle permet d’observer l’électropolymérisation des dérivés respectifs avec formation d’un dépôt isolant qui passive l’électrode et empêche la propagation de la polymérisation. En revanche, l’insertion d’une entité p-phénylène conjuguée entre le groupe thiophène et le fragment [M(N2O2)] porteur des substituants trifluorométhyles permet de mettre en évidence l’électropolymérisation de complexes bases de Schiff plan carré symétriques de Ni(II) et Cu(II) avec dépôt d’un film conducteur sur l’électrode. / The one-pot double condensation reaction of 2-thenoyltrifluoroacetone (TTAH) with primary diamines does not lead to the formation of the expected symmetric Schiff bases, but in the case of ethylenediamine (en) to a mixture of bis(trifluoroacetamide)ethylene and 7-(thiophene-2-yl)-5-(trifluoromethyl)-2,3-dihydro-1H-1,4-diazepine derivatives, while only 4-trifluoromethyl-2-(thiophen-2-yl)-1,5-benzodiazepine was isolated starting from o-phenylenediamine. The templated condensation reaction between ethylenediamine and bis(β-diketonate)metal complexes [M(TTA)2(S)2] (M = Co, Ni, Cu) gave exclusively the corresponding octahedral compounds [M(TTA)2(en)], where the ethylenediamine ligand chelates the metal center. The symmetrical Schiff base ligands [H2N2O2] bearing the 2-thienyl and the trifluoromethyl groups were prepared in two steps by (i) double condensation of acetylthiophene and ethylenediamine to generate the expected diimine, and (ii) treatment of the diimine with trifluoroacetic acid. In their corresponding Schiff base complexes of Co(II), Ni(II) and Cu(II), the metal ion is tetracoordinated in a square-planar environment. The coordination sphere is formed by the nitrogen and oxygen atoms of the dianionic tetradentate [N2O2]2- ligand. Those complexes as well as their analogues in which the CF3 group has been substituted for the 4-fluorophenyl unit, are inert toward electropolymerization. By contrast, replacement of the CF3 group by the parent methyl one allows electrochemical oxydation of the respective complexes and formation of an isolating deposit with passivation of the electrode and inhibition of the propagation of the polymerization. Interestingly, insertion of a conjugated p-phenylene unit between the 2-thienyl group and the CF3-substituted [M(N2O2] core permits the generation of a polythienyl-containing square planar Schiff base complexes of Ni(II) and Cu(II) films, and their deposition on an electrode using an electrochemical oxidation process.

[pt] Câncer é o nome dado a um conjunto de mais de 100 doenças e entre as possibilidades de tratamento está a quimioterapia. Após a descoberta das propriedades antitumorais do complexo de coordenação comumente chamado cisplatina, um dos compostos mais utilizados em neoplasias malignas, o estudo dos complexos metálicos teve um grande impulso e alguns compostos promissores de cobre(II) já foram desenvolvidos. Por outro lado, bases de Schiff derivadas de aminas e aldeídos aromáticos têm apresentado uma ampla aplicação em muitas áreas de pesquisa, sendo que algumas são farmacologicamente utilizadas na terapia anti-hipertensiva, hipnótica e antineoplásica. Neste contexto, no presente trabalho, foi sintetizado e caracterizado um ligante imínico binucleante sulfonado derivado da taurina, já conhecido na literatura: (LIT) e, a partir deste, seus complexos inéditos de Zn(II), Cu(II) e Ni(II), que foram caracterizados pelas seguintes técnicas: espectroscopia vibracional e eletrônica, análise elementar de CHNS, análise termogravimétrica, espectroscopia de ressonância paramagnética eletrônica (EPR) e modelagem molecular computacional. Os novos compostos obtidos neste trabalho são, a saber: composto (1), composto (2) e composto (3), em que LIT representa uma forma parcialmente hidrolisada de LIT. Os complexos 1 e 2 são os primeiros compostos binucleares do ligante LIT descritos. Neles, os centros metálicos são tetracoordenados e apresentam uma ponte exógena acetato coordenada nas formas bidentada, para o composto 1, e monodentada, para 2. Esta diferença na coordenação da ponte se dá, provavelmente, devido aos distintos arranjos geométricos em torno dos metais: enquanto o zinco apresenta um arranjo tetraédrico, o cobre mostra um do tipo quadrático. O complexo 3 é binuclear, composto por um dímero altamente simétrico envolvendo, como dito acima, uma forma parcialmente hidrolisada de LIT. Os centros metálicos são hexacoordenados, ligados por pontes endógenas fenólicas. Tanto 2 quanto 3 são silenciosos ao EPR. Foi realizado também um ensaio de toxicidade aguda em Artemia salina para as espécies hidrossolúveis LIT e complexo 1. Este ensaio mostra boa correlação com a atividade citotóxica para alguns tumores sólidos humanos. / [en] Cancer is a name given to a set of more than 100 diseases and among the possibilities of treatment is chemotherapy. After the discovery of the antitumor properties of the coordination complex commonly called cisplatin, it is one of the compounds most used in malignancies. The study of metal complexes had a big boost and some promising copper(II) compounds have been developed. Furthermore, the Schiff bases derived from aromatic aldehydes and amines present a wide range of applications in many areas of research, some of which are pharmacologically used in antihypertensive, hypnotic, and antineoplastic therapy. In this context, in the present study, we synthesized and characterized a binucleating imine ligand, derivative of taurine, already known in the literature: (LIT). New dinuclear Zn(II), Cu(II) and Ni(II) complexes of this ligand were synthesized, and were characterized by the following techniques: vibrational and electronic spectroscopies, CHNS elemental analysis, thermogravimetric analysis, electron paramagnetic resonance (EPR) and computational molecular modeling. The new compounds obtained in this work are: composite (1), composite (2) composite (3), where LIT represents a LIT partially hydrolyzed form. Complexes 1 and 2 are the first dinuclear compounds of the LIT ligand described. In these, metal centers are tetracoordinated, with the presence of an exogenous acetate bridge, which shows a bidentate coordination mode for compound 1 and a monodentate coordination pattern for 2. This difference occurs probably due to different geometrical arrangements around the metal centers: while zinc has a tetrahedral coordination geometry, copper shows one of the square planar type. On the other hand, compound 3 a dinuclear complex, which is composed of a highly symmetric dimer involving, as mentioned above, a partially hydrolyzed form of LIT. The hexacoordinated metal centers are connected by two endogenous phenolic bridges. Both 2 and 3 are EPR silent. An acute toxicity test on Artemia salina shrimp was also carried out for the hydro-soluble species LIT and 1. This assay shows good correlation with cytotoxic activity for some human solid tumors.