TABLE 4.
Observed absorption and computed vertical excitation energies for the most probable transitions of compounds P2, P5, U2, and U5, with largest oscillator strength, in different solvents.
| Dye | Solvent | Expt λmax (nm) | TD/CAM-B3LYP/6-311g** | |||
|---|---|---|---|---|---|---|
| Vertical excitation | Oscillator strength (f) | H–L Orbital contribution | ||||
| nm | eV | |||||
| P2 | Hex | 273 | 274.5 | 4.51 | 0.907 | 100% |
| THF | 276 | 276.2 | 4.48 | 0.920 | 100% | |
| DCM | 281 | 276.5 | 4.48 | 0.923 | 100% | |
| EtOH | 278 | 276.0 | 4.49 | 0.915 | 100% | |
| MeCN | 272 | 275.8 | 4.49 | 0.913 | 100% | |
| P5 | Hex | 290 | 307.6 | 4.03 | 0.378 | 100% |
| THF | 294 | 307.0 | 4.03 | 0.380 | 100% | |
| DCM | 297 | 307.1 | 4.03 | 0.383 | 100% | |
| EtOH | 296 | 306.4 | 4.04 | 0.370 | 100% | |
| MeCN | 292 | 306.3 | 4.04 | 0.367 | 100% | |
| U2 | Hex | 281 | 276.5 | 4.48 | 0.847 | 90.4% |
| THF | 215 | 277.0 | 4.47 | 0.951 | 96.8% | |
| DCM | 287 | 277.2 | 4.47 | 0.959 | 96.8% | |
| EtOH | 282 | 276.6 | 4.48 | 0.958 | 96.8% | |
| MeCN | 277 | 276.4 | 4.48 | 0.956 | 96.8% | |
| U5-trans | Hex | - | 295.4 | 4.19 | 0.423 | 100% |
| THF | 294 | 293.9 | 4.21 | 0.435 | 100% | |
| DCM | 294 | 294.0 | 4.21 | 0.438 | 100% | |
| EtOH | 290 | 293.1 | 4.23 | 0.429 | 100% | |
| MeCN | 286 | 292.8 | 4.23 | 0.426 | 100% | |