1969 Volume 42 Issue 4 Pages 855-863
The chemiluminescence of polyphenols with ozone in acetic acid was investigated in the presence and in the absence of rhodamine B. The emission intensity in the presence of rhodamine B (IM) was about 100–500 times as large as that in the absence of the dye (IP). From the measurement of the emission intensity vs. the reaction time, it was found that the time required to attain the peak intensity of IM is almost equal to that required to attain the peak of IP at equal concentration of polyphenol. A similarity was found in the spectral distributions of IM and the fluorescence emission of rhodamine B determined under comparable conditions. Rhodamine B was scarcely decomposed for the production of the enhanced emission; this lent support to the conclusion that the enhancement effect of rhodamine B is due to an energy-transfer from an excited species produced by the oxidation of polyphenols to the dye. Determining the changes in the absorption spectra during the luminescent reaction, we also found that the emission results not from the decomposition of polyphenols but from the decomposition of an intermediate compound. On the basis of these results, a reaction scheme was proposed. If the increment of the total light emitted by the enhancement effect, (Δ), is defined as:
Δ = (Total light emitted in the polyphenol+rhodamine B system)−(Total light emitted in polyphenol alone)−(Total light emitted in rhodamine B alone),
the scheme gave the following equation:
where [R]0 and [P]0 are the initial concentrations of rhodamine B and polyphenols respectively. A is the parameter, depending upon the experimental conditions. The values of Δ calculated from Eq. (1) were in fairly good agreement with the measured values.
This article cannot obtain the latest cited-by information.