Table 6.
Theoretical electronic absorption spectra of chromone-3-carboxylic acid (absorption wavelength λ (nm), excitation energies E (ev) and oscillator strengths (f) using TD-DFT/B3LYP/6–311++G (d,p) method.
| λ (nm) Theoretical Gas |
Experimental | E (eV) | (f) | Major contribution |
|---|---|---|---|---|
| 308 | 4.0218 | 0.0001 | H-1→LUMO (60%) | |
| 285 | 4.3370 | 0.0000 | H-2→LUMO (55%) | |
| 281 | 4.3981 | 0.0627 | HOMO→LUMO (89%) | |
| 263 | 4.6991 | 0.0000 | H-1→L+1 (80%) | |
| 260 | 4.7650 | 0.0019 | HOMO→L+1 (50%) | |
| 245 | 5.0422 | 0.0447 | H-4→LUMO (60%) | |
| 241 | 5.1295 | 0.0001 | H-2→L+1 (97%) | |
| 239 | 5.1740 | 0.2923 | HOMO→L+1 (41%) | |
| 223 | 5.5485 | 0.0435 | H-5→LUMO (74%) | |
| 220 | 5.6253 | 0.0810 | H-3→L+1 (30%) | |
| DMSO | ||||
| 291 | 4.2510 | 0.0001 | H-2→LUMO (91%) | |
| 288 | 305 | 4.2775 | 0.0786 | HOMO→LUMO (91%) |
| 267 | 4.6258 | 0.0068 | H-1→LUMO (46%) | |
| 253 | 4.8826 | 0.0000 | H-4→LUMO (45%) | |
| 252 | 4.9055 | 0.3693 | H-1→LUMO (44%) | |
| 241 | 5.1287 | 0.0000 | H-4→LUMO (39%) | |
| 232 | 5.3224 | 0.2091 | H-3→LUMO (76%) | |
| 231 | 5.3658 | 0.0001 | H-4→L+1 (80%) | |
| 226 | 5.4972 | 0.1555 | H-3→L+1 (13%) | |
| 214 | 5.7793 | 0.2034 | H-3→L+1 (63%) | |