Ancoragem de complexos de rutênio com ligantes siliados em sílica mesoporosa obtida via pirólise de spray
Arquivos
Data
2012-03-19
Autores
Sábio, Rafael Miguel [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
Este trabalho descreve a obtenção, caracterização e estudo espectroscópico de compósitos formados por uma matriz de sílica mesoporosa e complexos de Rutênio, com os ligantes 4-metil-4’-(N-trietóxisililpropil)amino-metil-2,2’-bipiridina (L3) e 4-metil-4’-(N-dimetiletóxisililpropil)amino-metil-2,2’-bipiridina (L1). As partículas de sílica mesoporosa foram obtidas pela metodologia de pirólise de aerossol, assistida por agentes direcionadores de estrutura: surfactantes brometo de cetiltrimetilamônio (CTAB) ou copolímero pluronic F-68, permitindo a obtenção “one step” da matriz sem a presença da fase orgânica preenchendo os poros, em o tempo total de síntese de apenas alguns minutos. Estas partículas foram obtidas com morfologia esférica, área superficial (BET) de até 1420 m2.g-1 e um sistema de poros (2 ou 5 nm) com um arranjo hexagonal, resultados confirmados por diferentes técnicas como microscopias eletrônicas (transmissão ou varredura) e espalhamento de raios X a baixo ângulo. Os ligantes bipiridina modificados foram preparados pela adição de 1 ou 3 grupamentos alcooxisilanos (L1 e L3, respectivamente) a molécula da bipiridina e caracterizados por ressonância magnética de 1H (1H RMN), espectrometria de massas, espectroscopia vibracional na região do infra-vermelho (FTIR) e análise elementar (AE). A partir dos ligantes modificados, complexos de rutênio ([Ru(bpy)2L3]Cl2 e [Ru(bpy)2L1]Cl2) foram sintetizados e caracterizados. Os complexos foram ligados covalentemente a superfície dos poros da matriz mesoporosa, pela reação dos grupos alcooxisilanos com grupos silanois presentes na matriz. A semelhança entre as propriedades luminescentes do compósito e dos complexos livres comprovam o papel da matriz como suporte, com taxas de ancoragem próxima à 0,97 mmol complexo.g-1 de sílica, gerando concentrações de complexos da ordem de até 0,82 complexos .nm-2 de sílica mesoporosa
This work describes the preparation, characterization and spectroscopic studies of luminescent composites are formed by mesoporous silica matrix and ruthenium complexes, with 4-methyl-4′-(methylaminopropyltriethoxysilyl)-2,2′-dipyridine (L3) and 4-methyl-4′-(methylaminopropyldimethylethoxysilyl)-2,2′-dipyridine (L1). Mesoporous silica particles were obtained by spray pyrolysis by using the structure-directing agent: cetyltrimethylammonium bromide (CTAB) or pluronic F-68 copolymer surfactants, allowing the one step production of matrix without organic phase inside the pores and reduced times of a few minutes. These particles presented spherical morphology, surface area (BET) of 1420 m2.g-1 and a system of pores (2 to 5 nm) with hexagonal structure, which was confirmed by electronic microscopy (transmission or scanning) and small angle X-rays scattering. Modified bipyridine ligands were obtained by the addition of 1 or 3 alcooxisilane groups (L1 and L3, respectively) to the bipyridine molecule which was confirmed by 1H nuclear magnetic resonance (1H NMR), mass spectrometry, infra-red vibrational spectroscopy (FTIR) and elemental analysis (EA). With the modified ligands, the complexes ([Ru(bpy)2L3]Cl2 and [Ru(bpy)2L1]Cl2) were synthesized and characterized. Afterwards the complexes were covalently linked to the surface of pores from the mesoporous matrix by the reaction of alcooxisilane groups with silanol groups of matrix. The similarity between the luminescent properties for the composite and free complexes puts in evidence the role played by matrix as a support, with a grafting rate around 0.97 mmol complexes.g-1 silica, reaching concentration of complexes up to 0.82 complex .nm-2 of mesoporous silica
This work describes the preparation, characterization and spectroscopic studies of luminescent composites are formed by mesoporous silica matrix and ruthenium complexes, with 4-methyl-4′-(methylaminopropyltriethoxysilyl)-2,2′-dipyridine (L3) and 4-methyl-4′-(methylaminopropyldimethylethoxysilyl)-2,2′-dipyridine (L1). Mesoporous silica particles were obtained by spray pyrolysis by using the structure-directing agent: cetyltrimethylammonium bromide (CTAB) or pluronic F-68 copolymer surfactants, allowing the one step production of matrix without organic phase inside the pores and reduced times of a few minutes. These particles presented spherical morphology, surface area (BET) of 1420 m2.g-1 and a system of pores (2 to 5 nm) with hexagonal structure, which was confirmed by electronic microscopy (transmission or scanning) and small angle X-rays scattering. Modified bipyridine ligands were obtained by the addition of 1 or 3 alcooxisilane groups (L1 and L3, respectively) to the bipyridine molecule which was confirmed by 1H nuclear magnetic resonance (1H NMR), mass spectrometry, infra-red vibrational spectroscopy (FTIR) and elemental analysis (EA). With the modified ligands, the complexes ([Ru(bpy)2L3]Cl2 and [Ru(bpy)2L1]Cl2) were synthesized and characterized. Afterwards the complexes were covalently linked to the surface of pores from the mesoporous matrix by the reaction of alcooxisilane groups with silanol groups of matrix. The similarity between the luminescent properties for the composite and free complexes puts in evidence the role played by matrix as a support, with a grafting rate around 0.97 mmol complexes.g-1 silica, reaching concentration of complexes up to 0.82 complex .nm-2 of mesoporous silica
Descrição
Palavras-chave
Quimica organica, Pirolise, Luminescencia, Pyrolysis
Como citar
SÁBIO, Rafael Miguel. Ancoragem de complexos de rutênio com ligantes siliados em sílica mesoporosa obtida via pirólise de spray. 2012. 124 f. Dissertação (mestrado) - Universidade Estadual Paulista, Instituto de Química, 2012.