Takeuchi and Tahara. 10.1073/pnas.0610141104. |
Fig. 10. Steady-state fluorescence spectra of 7-azaindole in hexane (1 ´ 10-2 mol·dm-3) measured at room temperature with four excitation wavelengths. These spectra were normalized by the peak intensity in the UV region after correction for the instrumental sensitivity and reabsorption of the sample.
Fig. 11. Femtosecond time-resolved fluorescence signals at ≈440 nm measured with excitation at 313 nm (a) and 270 nm (b).
Fig. 12. The absorption spectra of the S1 and S2 states of the 7-azaindole dimer obtained from the excitation wavelength dependence of the femtosecond fluorescence data.
Table 2. Parameters for the spectral decomposition of the dimer absorption as a function of excitation wavelength (λex)
λ ex, nm | A 1/A2 | g | ε S2, M-1·cm-1 | ε S1, M-1·cm-1 |
280 | 0.35 | 0.66 | 4700 | 2400 |
287 | 0.30 | 0.56 | 4500 | 3600 |
293 | 0.21 | 0.37 | 2800 | 4700 |
300 | 0.29 | 0.54 | 2600 | 2300 |
307 | 0.09 | 0.16 | 280 | 1500 |
313 | 0.013 | 0.021 | 19 | 860 |
A
1/A2 represents the amplitude ratio of the 0.2-ps (A1) and the 1.1-ps (A2) components obtained by the fitting analysis of the dimer fluorescence at 380 nm. g is the extinction-coefficient ratio of the S2 and S1 states of the 7-azaindole dimer defined by Eq. 1 in the SI Text.