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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.
1

Synthesis and Characterization of Titanium Complexes of Aryl Diamides and Tantalum Complexes of Diphenolate Phosphine Ligands

Tsai, Ting-Ting 28 June 2012 (has links)
The novel chelating ligand, Me[NOON]H2 (N,N'-((ethane-1,2-diylbis(oxy))-bis(ethane-2,1-diyl))- bis(2,6-dimethylaniline)), have been synthesized successfully and characterized by NMR. The lithium complexes of the aryl diamide ligand have also been synthesized by n-BuLi react with neutral ligand, Me[NOON]H2. And the lithium complexes is a ether adduct according to the 1H NMR. The lithium complex, Me[NOON]Li2(OEt2) react with Ti(OiPr)4 and TiCl4(THF)2 to form the NOON titanium alkoxide and dichloride complexes respectively, and they have been characterized by 1H NMR and X-ray diffraction. These NOON titanium complexes are expected to be a catalyst for the ring opening polymerization of lactide or caprolactone in the future. The tantalum complexes of diphenolate phosphine ligands have been synthesized and characterized successfully by NMR, X-ray diffraction, and elemental analysis. The tantalum complexes, [tBuOPO]2TaX (X=Me, Et, H) is produced by the reaction of [tBuOPO]2TaCl with Grignard reagent (MeMgBr and EtMgCl) and superhydride(LiHBEt3). These tantalum complexes will be applied in dinitrogen activation in the future work.
2

Modified Organoclay Containing Chelating Ligand for Adsorption of Heavy Metals in Solution.

Addy, Mary Akuyea 17 December 2011 (has links) (PDF)
Presence of a chelating ligand in the clay structure significantly improves its ability to immobilize heavy metals from contaminated sludge or wastewater. Two-step modification procedure comprising sequential pillaring and grafting of chelating agent to the modified clay is involved. Montmorillonite and kaolin were chosen as typical examples of expandable and non-expandable clays, correspondingly. Modifications with silica and ferric oxide were targeted on development of mesoporous structure. Laboratory tests of the organoclay efficiency for purification of wastewater were conducted with the most promising sample, i.e. organoclay with the highest specific loading of chelating agent. Experiments were conducted with model wastewater containing either individual or mixed cations of heavy metals. The modified organoclay displayed a high adsorption capacity on heavy metal cations even in acidic media. The method of modification presented in this work can be used for synthesis of efficient adsorbents for applications in contaminated areas.
3

Compostos de coordenação de 2,2´-sulfinildietanol com alguns metais de transição / Coordination compounds of 2,2\'-sulfinyldiethanol with some transition metals

Osorio, Viktoria Klara Lakatos 09 March 1972 (has links)
Foram preparados complexos de 2,2--sulfinildietanol (sde) com alguns percloratos e cloretos de metais bivalentes. Os percloratos apresentam a formula geral [M(sde) 2] (C10 4 ) 2 , em que M= Mn, Co, Ni, Cu e Zn, e [M(sde) 3] (C10 4 )2 , em que M= Co e Fe. São cristalinos e muito higroscópicos. Os diagramas de difração de raios-X sugerem que os dois complexos [M(sde) 3] (C10 4 ) 2 são isomorfos. Na série [M(sde)2 ] (C10 4 ) 2 , somente os compostos de cobalto e níquel deram diagramas semelhantes. Os espectros vibracionais são muito difíceis de interpretar. Conclusões inequívocas a respeito da posição da vibração de estiramento S = 0 não puderam ser obtidas. A análise dos espectros sugere que: a) os íons perclorato não se acham coordenados, b) ambos os grupos hidroxila do ligante estão coordenados ao metal nos complexos [M(sde) 2 ] (C10 4 ) 2 , e c) somente um grupo hidroxila está coordenado nos complexos [M(sde) 3 ] (C104)2. As condutâncias molares dos complexos em solução em nitrometano e acetonitrila indicam comportamento de eletrólitos 1:2. As massas moleculares aparentes dos complexos dissolvi dos em acetonitrila dependem da concentração. Isto pode ser explica do como resultante de uma ligeira dissociacão em soluções diluídas e da formação de pares iônicos em concentrações maiores. Os momentos magnéticos dos complexos estão dentro dos intervalos esperados para complexos octaédricos de spin alto. Os espectros eletrônicos dos complexos de ferro, cobalto e níquel são também característicos de espécies de spin alto com simetria Oh. A partir dos espectros de absorção eletrônica dos complexos de cobalto e níquel, foram calculados os parâmetros de campo ligante Dq e &#946;. 0 ligante 2,2- -sulfinildietanol fornece valores maiores de Dq do que os sulfóxidos e álcoois monodentados. Isto pode ser atribuído ao efeito quelato. Os valores de Dq dos complexos de cobalto indicam que o 2,2--sulfinildietanol atua como um ligante tridentado no complexo [Co(sde)<SUB2](C104 )2 e como bidentado no complexo [Co(sde)3] (C104)2. Foram também obtidos os complexos de cloretos apresentando as estequiometrias CoC12.2H20.sde, CoC12.sde e PdC12.sde. Os espectros de absorção no infravermelho indicam que o sde se liga pelo oxigênio nos complexos com CoC12 e pelo enxofre no complexo com PdC12. Uma estrutura binuclear com pontes de cloreto é sugerida para o complexo de paládio, com base em seu espectro infravermelho longínquo. A condutância molar deste composto em nitrometano e acetonitrila mostra que ele não é iônico. O comportamento dos complexos de cloreto de cobalto em solução em acetonitrila a tentativamente explicado com base na formação do ânion tetraédrico tetraclorocobaltato(II) e um cátion contendo cobalto(II) octaedricamente coordenado. / 2,2\' -sulfinyldiethanol (sde) complexes of some divalent metal perchlorates and chlorides were prepared. The perchlorates have the general formula [M(sde)2] (C104)2 , where M = Mn, Co, Ni, Cu and Zn, and [M(sde)3] (C104)2, where M = Co and Fe. They are crystalline and very hygroscopic. X- ray diffraction patterns suggest that the two complexes [M(sde)3] (C104)2 are isomorphous. In the [M(sde)2] (C104)2 series only cobalt and nickel compounds gave similar patterns.The vibrational spectra are very difficult to interpret. Unequivocal conclusions regarding the position of S = 0 stretching vibration could not be drawn. An analysis of the spectra does suggest that: a) the perchlorate ions are not coordinated, b) both ligand hydroxyl groups are coordinated to the metal in the [M(sde)2] (C104)2 complexes, and c) only one hydroxyl group is coordinated in the [M(sde)3] (C104)2 complexes.The molar conductance of the complexes in nitromethane and acetonitrile solutions indicate their behavior as 1:2 electrolytes. The apparent molecular weights of the complexes dissolved in acetonitrile depend upon the concentrations. This can be explained by a slight dissociation in dilute solutions and ion-pair formation in more concentrated ones. The magnetic moments of the complexes are within the range expected for high-spin octahedral complexes. The electronic spectra of the iron, cobalt and nickel complexes are also characteristic of high-spin species in Oh symmetry. From the electronic absorption spectra of cobalt and nickel complexes, the ligand field parameters, Dq and &#946; were calculated. The ligand 2,2- -sulfinyldiethanol gives larger Dq values than do monodentate sulfoxides or alcohols. This may be attributed to the chelate effect. The Dq values for the cobalt complexes indicate that 2,2--sulfinyldiethanol acts as a tridentate ligand in the [Co(sde)2] (C104)2 complex and as a bidentate one in the [Co(sde)3] (C104)2 complex. The chloro complexes having the stoichiometries CoC12 .2H20.sde, CoC12.sde, and PdC12 .sde were also obtained. Infrared spectra indicate that sde is oxygen-bonded in CoC12 complexes while it is sulphur-bonded in PdC12 complex. A chloro-bridged binuclear structure is suggested for the palladium complex, on the basis of its far infrared spectrum. The molar conductance of this compound in nitromethane and acetonitrile shows a non-ionic nature. The behavior of the cobalt chloride complexes in acetonitrile solution is tentatively explained on the basis of the formation of the tetrahedral tetrachlorocobaltate (II) ani , n and a cation containing octahedrally coordinated cobalt(II).
4

Compostos de coordenação de 2,2´-sulfinildietanol com alguns metais de transição / Coordination compounds of 2,2\'-sulfinyldiethanol with some transition metals

Viktoria Klara Lakatos Osorio 09 March 1972 (has links)
Foram preparados complexos de 2,2--sulfinildietanol (sde) com alguns percloratos e cloretos de metais bivalentes. Os percloratos apresentam a formula geral [M(sde) 2] (C10 4 ) 2 , em que M= Mn, Co, Ni, Cu e Zn, e [M(sde) 3] (C10 4 )2 , em que M= Co e Fe. São cristalinos e muito higroscópicos. Os diagramas de difração de raios-X sugerem que os dois complexos [M(sde) 3] (C10 4 ) 2 são isomorfos. Na série [M(sde)2 ] (C10 4 ) 2 , somente os compostos de cobalto e níquel deram diagramas semelhantes. Os espectros vibracionais são muito difíceis de interpretar. Conclusões inequívocas a respeito da posição da vibração de estiramento S = 0 não puderam ser obtidas. A análise dos espectros sugere que: a) os íons perclorato não se acham coordenados, b) ambos os grupos hidroxila do ligante estão coordenados ao metal nos complexos [M(sde) 2 ] (C10 4 ) 2 , e c) somente um grupo hidroxila está coordenado nos complexos [M(sde) 3 ] (C104)2. As condutâncias molares dos complexos em solução em nitrometano e acetonitrila indicam comportamento de eletrólitos 1:2. As massas moleculares aparentes dos complexos dissolvi dos em acetonitrila dependem da concentração. Isto pode ser explica do como resultante de uma ligeira dissociacão em soluções diluídas e da formação de pares iônicos em concentrações maiores. Os momentos magnéticos dos complexos estão dentro dos intervalos esperados para complexos octaédricos de spin alto. Os espectros eletrônicos dos complexos de ferro, cobalto e níquel são também característicos de espécies de spin alto com simetria Oh. A partir dos espectros de absorção eletrônica dos complexos de cobalto e níquel, foram calculados os parâmetros de campo ligante Dq e &#946;. 0 ligante 2,2- -sulfinildietanol fornece valores maiores de Dq do que os sulfóxidos e álcoois monodentados. Isto pode ser atribuído ao efeito quelato. Os valores de Dq dos complexos de cobalto indicam que o 2,2--sulfinildietanol atua como um ligante tridentado no complexo [Co(sde)<SUB2](C104 )2 e como bidentado no complexo [Co(sde)3] (C104)2. Foram também obtidos os complexos de cloretos apresentando as estequiometrias CoC12.2H20.sde, CoC12.sde e PdC12.sde. Os espectros de absorção no infravermelho indicam que o sde se liga pelo oxigênio nos complexos com CoC12 e pelo enxofre no complexo com PdC12. Uma estrutura binuclear com pontes de cloreto é sugerida para o complexo de paládio, com base em seu espectro infravermelho longínquo. A condutância molar deste composto em nitrometano e acetonitrila mostra que ele não é iônico. O comportamento dos complexos de cloreto de cobalto em solução em acetonitrila a tentativamente explicado com base na formação do ânion tetraédrico tetraclorocobaltato(II) e um cátion contendo cobalto(II) octaedricamente coordenado. / 2,2\' -sulfinyldiethanol (sde) complexes of some divalent metal perchlorates and chlorides were prepared. The perchlorates have the general formula [M(sde)2] (C104)2 , where M = Mn, Co, Ni, Cu and Zn, and [M(sde)3] (C104)2, where M = Co and Fe. They are crystalline and very hygroscopic. X- ray diffraction patterns suggest that the two complexes [M(sde)3] (C104)2 are isomorphous. In the [M(sde)2] (C104)2 series only cobalt and nickel compounds gave similar patterns.The vibrational spectra are very difficult to interpret. Unequivocal conclusions regarding the position of S = 0 stretching vibration could not be drawn. An analysis of the spectra does suggest that: a) the perchlorate ions are not coordinated, b) both ligand hydroxyl groups are coordinated to the metal in the [M(sde)2] (C104)2 complexes, and c) only one hydroxyl group is coordinated in the [M(sde)3] (C104)2 complexes.The molar conductance of the complexes in nitromethane and acetonitrile solutions indicate their behavior as 1:2 electrolytes. The apparent molecular weights of the complexes dissolved in acetonitrile depend upon the concentrations. This can be explained by a slight dissociation in dilute solutions and ion-pair formation in more concentrated ones. The magnetic moments of the complexes are within the range expected for high-spin octahedral complexes. The electronic spectra of the iron, cobalt and nickel complexes are also characteristic of high-spin species in Oh symmetry. From the electronic absorption spectra of cobalt and nickel complexes, the ligand field parameters, Dq and &#946; were calculated. The ligand 2,2- -sulfinyldiethanol gives larger Dq values than do monodentate sulfoxides or alcohols. This may be attributed to the chelate effect. The Dq values for the cobalt complexes indicate that 2,2--sulfinyldiethanol acts as a tridentate ligand in the [Co(sde)2] (C104)2 complex and as a bidentate one in the [Co(sde)3] (C104)2 complex. The chloro complexes having the stoichiometries CoC12 .2H20.sde, CoC12.sde, and PdC12 .sde were also obtained. Infrared spectra indicate that sde is oxygen-bonded in CoC12 complexes while it is sulphur-bonded in PdC12 complex. A chloro-bridged binuclear structure is suggested for the palladium complex, on the basis of its far infrared spectrum. The molar conductance of this compound in nitromethane and acetonitrile shows a non-ionic nature. The behavior of the cobalt chloride complexes in acetonitrile solution is tentatively explained on the basis of the formation of the tetrahedral tetrachlorocobaltate (II) ani , n and a cation containing octahedrally coordinated cobalt(II).

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