Table 1. Fit Parameters Obtained from Fits of the Absorption Spectra to a Vibronic Progression of eq 1a.
| fit parameters | xylindein in CB (ε = 5.6) | xylindein in DCM (ε = 8.9) | dimethylxylindein in DCM |
|---|---|---|---|
| A0 (norm) | 0.35; 0.65 | 0.3; 0.7 | 1 |
| EX (eV) | 1.82; 1.88 | 1.84; 1.90 [1.89; 1.93] | 2.17 [2.14] |
| EV (eV) | 0.13; 0.16 | 0.13; 0.16 | 0.18 |
| S | 0.87; 0.87 | 0.77; 0.92 | 0.99 |
| σ0 (eV) | 0.07; 0.09 | 0.06; 0.08 | 0.11 |
| Δσ | 0.51; 0.51 | 0.55; 0.59 | 0.53 |
a
In the case of xylindein, a sum of two vibronic progressions, with the corresponding parameters listed, was needed to obtain a good fit. Numbers in the brackets correspond to values of vertical energies for two xylindein tautomers calculated as described in Materials and Methods.