AI Article Synopsis
- The study analyzes the interaction between xanthene dyes (Eosin Y, Erythrosin B, and Rose Bengal) and amino-terminated PAMAM dendrimers in alkaline solutions, noting significant changes in UV/Vis absorption and fluorescence.
- High binding constants indicate strong interactions between the dyes and dendrimers, with bathochromic shifts in absorption spectra correlating to dendrimer size.
- Laser flash photolysis reveals decreased triplet lifetimes and increased absorption of semireduced dyes, suggesting efficient electron transfer from PAMAM to the xanthene dyes.
Article Abstract
The photophysical and photochemical properties of the xanthene dyes Eosin Y, Erythrosin B, and Rose Bengal are evaluated in the presence of amino-terminated polyamidoamine (PAMAM) dendrimers of relatively high generation (G3-G5) in alkaline aqueous solution. UV/Vis absorption and fluorescence spectra of the dyes show bathochromic shifts, which correlate with the size of the dendrimer. Binding constants (K ) are calculated from absorption data. The resulting high K values indicate strong interactions between both molecules. Triplet-triplet absorption spectra of the dyes are recorded by laser flash photolysis, and a decrease in the triplet lifetimes is observed in the presence of dendrimers. At the same time, an increase in the absorption of the semireduced form of the dyes is observed. Rate constants for triplet quenching ( k ) and radical quantum yields (Φ ) are obtained. The results are explained by a very efficient electron-transfer process from PAMAM to xanthene dyes for all of the dye/dendrimer couples that are evaluated.
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| http://dx.doi.org/10.1002/cphc.201701295 | DOI Listing |
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