Complexos fosfínicos de rutênio com ligantes o-fenilênicos: síntese, caracterização e aplicação como catalisadores em reação de hidrogenação

Detalhes bibliográficos
Ano de defesa: 2010
Autor(a) principal: Francisco, Thiago dos Santos
Orientador(a): Não Informado pela instituição
Banca de defesa: Não Informado pela instituição
Tipo de documento: Dissertação
Tipo de acesso: Acesso aberto
Idioma: por
Instituição de defesa: Não Informado pela instituição
Programa de Pós-Graduação: Não Informado pela instituição
Departamento: Não Informado pela instituição
País: Não Informado pela instituição
Palavras-chave em Português:
Link de acesso: http://www.repositorio.ufc.br/handle/riufc/20122
Resumo: 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), 3,3’,4,4’-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.