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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

Complexos mono, bi e trinucleares de metais de transição com bases de Schiff tridentadas tipo ONN e tetradentadas do tipo ONNO : síntese, caracterização e estudos como catalisadores na oxidação de catecois / Mono, bi e trinuclear complexes of transition metals with schiff bases tridentate type onn and tetradentate type onno : synthesis and characterization studies and as catalysts in the oxidation of catechols.

Silva, Ricardo Soares Mota 11 September 2015 (has links)
Submitted by Izabel Franco (izabel-franco@ufscar.br) on 2016-09-20T17:45:13Z No. of bitstreams: 1 TeseRSMS.pdf: 5554838 bytes, checksum: e6ac3458b2c5b7d61474d8e8ed6cbe72 (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-09-21T12:37:34Z (GMT) No. of bitstreams: 1 TeseRSMS.pdf: 5554838 bytes, checksum: e6ac3458b2c5b7d61474d8e8ed6cbe72 (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-09-21T12:37:42Z (GMT) No. of bitstreams: 1 TeseRSMS.pdf: 5554838 bytes, checksum: e6ac3458b2c5b7d61474d8e8ed6cbe72 (MD5) / Made available in DSpace on 2016-09-21T12:37:50Z (GMT). No. of bitstreams: 1 TeseRSMS.pdf: 5554838 bytes, checksum: e6ac3458b2c5b7d61474d8e8ed6cbe72 (MD5) Previous issue date: 2015-09-09 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Salen-type complexes are an important class of coordination compounds, which have been used to catalyze a wide variety of reactions in various homogeneous and heterogeneous systems. Complexes of transition metals are very versatile and participate in many chemical processes, which make the study of these very interesting. Research shows that the complexes of salen [salen = N, N'-ethylenebis (salicilidenoamina)] are efficient catalysts, and some compounds of this type have been investigated as catalysts in the oxidation of catechol. In this work were synthesized six types of compounds, ligands, symmetric mononuclear complexes, tridentate complexes, asymmetric mononuclear complexes, binuclear and trinuclear complexes. The series have satisfactory yields. The synthesized compounds in this work were characterized by melting point, elemental analysis, vibrational spectroscopy in the IR region, absorption spectra in the UV-vis, conductivity measurements and solubility. The ligands and three palladium(II) complexes were also characterized by nuclear magnetic resonance. From these characterizations, comparisons were made between ligands, mononuclear, tridentate, binuclear and trinuclear complexes, and also with respect to the effects of the substituents on the aromatic ring at positions 4 and 5. The kinetics was performed using a spectrophotometer, following the formation of the product derived from oxidation of 3,5-di-tert-butylcatechol at 400 nm. In kinetic study were tested the binuclear and the trinuclear complexes which showed catalytic activities compatible with those of similar complexes described in the literature, among them we can mention the binuclear complexes [Cu(Cu(t-4DEA-salcn))Cl2] e [Cu(Cu(t-5NO2- salcn))Cl2] , kcat = 0,132 s-1 e kcat = 0,108 s-1, respectively; and the palladium(II) copper(II) binuclear complexes [Cu(Pd(t-salcn))Cl2] e [Cu(Pd(t-4-DEA-salcn))Cl2], kcat = 0,113 s-1 e kcat = 0,240 s-1, respectively. / Salen complexos são uma importante classe de compostos de coordenação, os quais vêm sendo usados para catalisar uma larga variedade de reações em vários sistemas homogêneos e heterogêneos. Complexos de metais de transição são muito versáteis e tem participação em muitos processos químicos, o que torna o estudo desses muito interessantes. Pesquisas mostram que os complexos de salen [salen= N,N’-etilenobis(salicilidenoamina)] são catalisadores eficientes, sendo que, alguns compostos deste tipo foram investigados como catalisadores na oxidação de catecois. Foram sintetizados nesse trabalho seis tipos de compostos: ligantes, complexos mononucleares simétricos, complexos com ligantes tridentados, complexos mononucleares assimétricos, complexos binucleares e um complexo trinuclear. As séries apresentaram rendimentos satisfatórios. Os compostos sintetizados nesse trabalho foram caracterizados por ponto de fusão, análise elementar, espectroscopia vibracional na região do IV, espectroscopia de absorção na região do UV-vis, medidas de condutividade e solubilidades, sendo os ligantes e três complexos de paládio(II) também caracterizados por Ressonância Magnética Nuclear. A partir dessas caracterizações, foram feitas comparações entre ligantes, complexos tridentados, complexos mononucleares, binucleares e trinuclear, e também com respeito aos efeitos dos substituintes no anel aromático 4 e 5. As cinéticas foram estudadas por meio espectrofotométrico acoplado a banho termostatizado acompanhando-se a formação do produto derivado da oxidação do 3,5-di-terc-Butilcatecol em 400 nm. No estudo cinético foram testados os complexos binucleares e o trinuclear os quais apresentaram atividades catalíticas compatíveis com as de complexos similares descritos na literatura. Dentre estes podemos citar os complexos binucleares simétricos [Cu(Cu(t-4DEA-salcn))Cl2] e [Cu(Cu(t-5NO2- salcn))Cl2] , kcat = 0,132 s-1 e kcat = 0,108 s-1, respectivamente; e os complexos binucleares paládio(II) cobre(II) [Cu(Pd(t-salcn))Cl2] e [Cu(Pd(t-4-DEA-salcn))Cl2], kcat = 0,113 s-1 e kcat = 0,240 s-1, respectivamente.

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