Artículo
The interaction of the excited states of safranine-O with low generation carboxyl terminated PAMAM dendrimers in an aqueous medium
Militello, María Paula
; Altamirano, Marcela Susana; Bertolotti, Sonia Graciela
; Previtali, Carlos Mario
Fecha de publicación:
06/2018
Editorial:
Royal Society of Chemistry
Revista:
Photochemical and Photobiological Sciences
ISSN:
1474-905X
e-ISSN:
2041-9724
Idioma:
Inglés
Tipo de recurso:
Artículo publicado
Clasificación temática:
Resumen
The interaction of the singlet and triplet excited states of the synthetic dye safranine-O with carboxyl-terminated poly(amidoamine) (PAMAM) dendrimers was investigated in a buffer solution at pH 8. Low half-generation PAMAM dendrimers (G -0.5; G +0.5: G 1.5) were employed. The UV-vis absorption spectrum of the dye presents only a very small red shift in the presence of dendrimers. Fluorescence quenching was detected and it was interpreted by a static mechanism in terms of the association of the dye with the dendrimer. Laser flash photolysis experiments were carried out and transient absorption spectra of the triplet and radicals were obtained. The triplet state is quenched by the dendrimers with rate constants well below the diffusional limit. The quenching process was characterized as an electron transfer process and the quantum yield of radicals was estimated. It was found that radicals are formed with a high efficiency in the triplet quenching reaction.
Palabras clave:
DENDRIMERS
,
PAMAM
,
SAFRANINE
,
TRIPLET
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Identificadores
Colecciones
Articulos(CCT - CORDOBA)
Articulos de CTRO.CIENTIFICO TECNOL.CONICET - CORDOBA
Articulos de CTRO.CIENTIFICO TECNOL.CONICET - CORDOBA
Citación
Militello, María Paula; Altamirano, Marcela Susana; Bertolotti, Sonia Graciela; Previtali, Carlos Mario; The interaction of the excited states of safranine-O with low generation carboxyl terminated PAMAM dendrimers in an aqueous medium; Royal Society of Chemistry; Photochemical and Photobiological Sciences; 17; 5; 6-2018; 652-659
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