Table 3.
UV/Vis absorption band maxima of enol form (λabs of E), emission band maxima of enol (λemis of E) and emission band maxima of keto forms (λemis of K), the excitation energy (Eex), and the oscillator strength (f) as well as their major contribution (%) calculated by TD-PBE0/def2-SVP level of theory.
| Compounds | UV/Vis Absorption | Emission | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| λabs of E (nm) |
Eex (eV) |
f | MOs (%contribution) | λemis of E* (nm) |
Eex (eV) |
f | λemis of K* (nm) |
Eex (eV) |
f | |
| 3HF | 341 | 3.63 | 0.4907 | HOMO→LUMO (98%) | 390 | 3.18 | 0.5454 | 514 | 2.41 | 0.4632 |
| 3HFW | 351 | 3.53 | 0.4857 | HOMO→LUMO (98%) | 408 | 3.04 | 0.5335 | 504 | 2.46 | 0.4619 |
| Form I | 345 | 3.59 | 0.4618 | HOMO→LUMO (98%) | 392 | 3.16 | 0.5123 | 524 | 2.36 | 0.3692 |
| Form II | 345 | 3.59 | 0.4081 | HOMO→LUMO (98%) | 393 | 3.15 | 0.4689 | 528 | 2.35 | 0.3792 |
| Form I-W | 353 | 3.51 | 0.4288 | HOMO→LUMO (98%) | 399 | 3.11 | 0.5213 | 529 | 2.34 | 0.3708 |
| Form II-W | 350 | 3.54 | 0.4174 | HOMO→LUMO (98%) | 412 | 3.01 | 0.4575 | 508 | 2.44 | 0.3899 |