CoordenaÃÃo de AperfeiÃoamento de NÃvel Superior / FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / The dependence on the experimental conditions of the production of phosphine ruthenium complexes containing o-phenylene ligands was analyzed in this work. The reaction between mer-[RuIIICl3(dppb)(H2O)] and [RuIICl2(dppb)(PPh3)] starting complexes, where dppb = 1,4-bis(diphenylphosphine)butane and PPh3 = triphenilphosphine, and 4-cloro-1,2-phenylenediamine (opda-Clcat), 3,3â,4,4â-tetraaminebiphenyl (tabcat,cat), benzenedithiol (bzditiolcat), and 9,10-phenantrequinone (fenantq) species resulted in the production of trans-[RuIICl2(dppb)(opda-Clcat)], cis-[RuIICl2(dppb)(opda-Clq)], trans-[RuIICl2(dppb)(tabq,cat)], cis-[RuIICl2(dppb)(tabq,cat)], trans-[RuIICl2(dppb)(Bzditiolcat)], and trans-[RuIICl2(dppb)(fenantq)] complexes. These compounds were characterized by means of electrochemical techniques, electronic and vibrational spectroscopies, and 31P{1H} nuclear magnetic resonance. The 31P{1H} NMR technique allowed the determination of the cis and trans isomers based on correlation with previously reported data and with the isolated compounds from the syntheses made from the [RuIICl2(dppb)(PPh3)] reduced starting complex. The mechanistic scheme for the reaction between the mer-[RuIIICl3(dppb)(H2O)] complex and the opda-Clcat ligand was proposed based on kinetics experiments acquired by using stopped-flow technique. In accordance with the kinetic results, there is the suggestion of the formation of a binuclear intermediate whose metal centers are reduced through an intra-molecular electron transfer process where the ligand is oxidized. This conclusion reinforces the results reported in the literature for the opda ligand. All the synthesized complexes presented catalytic activity toward the hydrogenation reaction of acetophenone molecule. Among these, based on preliminary results, the cis-[RuIICl2(dppb)(opda-Clq)], trans-[RuIICl2(dppb)(tabq,cat)], and cis-[RuIICl2(dppb)(tabq,cat)] complexes presented a conversion of 100%. Although a more careful study should be done, this result suggests that these compounds are able to act as catalysts in reduction reaction of polar double bonding. / A influÃncia das condiÃÃes reacionais na formaÃÃo de complexos fosfÃnicos de rutÃnio com ligantes o-fenilÃnicos foram estudadas neste trabalho. A reaÃÃo dos complexos mer-[RuIIICl3(dppb)(H2O)] e [RuIICl2(dppb)(PPh3)], onde dppb = 1,4-bis(difenilfosfina)butano e PPh3 = trifenilfosfina, e os ligantes o-fenilÃnicos 4-cloro-1,2-fenilenodiamina (opda-Clcat), 3,3â,4,4â-tetraaminobifenil (tabcat,cat), benzenoditiol (bzditiolcat) e 9,10-fenantrequinona (fenantq) resultaram na formaÃÃo dos complexos trans-[RuIICl2(dppb)(opda-Clcat)], cis-[RuIICl2(dppb)(opda-Clq)], trans-[RuIICl2(dppb)(tabq,cat)], cis-[RuIICl2(dppb)(tabq,cat)], trans-[RuIICl2(dppb)(Bzditiolcat)] e trans-[RuIICl2(dppb)(fenantq)]. A caracterizaÃÃo destas espÃcies foi realizada por tÃcnicas eletroquÃmicas, espectroscopias eletrÃnica e vibracional e ressonÃncia magnÃtica nuclear de 31P{1H}. A tÃcnica de RMN 31P{1H} permitiu a identificaÃÃo dos isÃmeros cis e trans dos complexos sintetizados atravÃs de comparaÃÃo com dados da literatura e com espectros obtidos para os produtos isolados a partir do complexo reduzido, [RuIICl2(dppb)(PPh3)]. A proposta mecanÃstica para a reaÃÃo entre o complexo mer-[RuIIICl3(dppb)(H2O)] e o ligante opda-Clcat foi baseada em experimentos cinÃticos obtidos atravÃs da tÃcnica de stopped-flow. De acordo com os resultados cinÃticos, hà a sugestÃo de formaÃÃo de um intermediÃrio binuclear cujos centros metÃlicos sÃo reduzidos atravÃs de um processo de transferÃncia de elÃtrons intramolecular onde o ligante sofre oxidaÃÃo. Esta conclusÃo reforÃa os resultados reportados na literatura para o ligante opda. Todos os complexos sintetizados apresentaram atividade catalÃtica em relaÃÃo à reaÃÃo de hidrogenaÃÃo da molÃcula de acetofenona sendo que, de acordo com os ensaios realizados, os complexos cis-[RuIICl2(dppb)(opda-Clq)], trans-[RuIICl2(dppb)(tabq,cat)] e cis-[RuIICl2(dppb)(tabq,cat)] apresentaram uma conversÃo de 100%. Embora seja necessÃrio um estudo mais criterioso, este resultado sugere que estes compostos podem atuar como catalisadores de reaÃÃo de reduÃÃo de duplas ligaÃÃes polares.
| Identifer | oai:union.ndltd.org:IBICT/oai:www.teses.ufc.br:7097 |
| Date | 26 October 2010 |
| Creators | Thiago dos Santos Francisco |
| Contributors | Izaura Cirino Nogueira DiÃgenes, Alzir Azevedo Batista, Elisane Longhinotti |
| Publisher | Universidade Federal do CearÃ, Programa de PÃs-GraduaÃÃo em QuÃmica, UFC, BR |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/masterThesis |
| Format | application/pdf |
| Source | reponame:Biblioteca Digital de Teses e Dissertações da UFC, instname:Universidade Federal do Ceará, instacron:UFC |
| Rights | info:eu-repo/semantics/openAccess |
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