Table 2. Mono-, Di-, Tri-, and Tetrachlorinated Azobenzenes: Vertical Excitation Energies (TD-PBE0/def2-TZVP) and Photoswitch Structures (PBE0-D3/def2-TZVP).
| config. | N=N [Å] | ΦS(Ar1) [deg] | ΦS(Ar2) [deg] | Ψ [deg] | S0 → S1 [nm] | |
|---|---|---|---|---|---|---|
| 1 | trans | 1.242 | 0.0 | 0.0 | 180.0 | 483.6 |
| cis | 1.234 | 52.0 | 52.0 | 8.5 | 470.0 | |
| 3 | trans | 1.242 | 0.2 | 1.4 | 179.9 | 501.9 |
| cis | 1.232 | 51.7 | 63.0 | 9.5 | 454.3 | |
| 4 | trans | 1.243 | 0.7 | 2.7 | 179.8 | 520.6 |
| cis | 1.231 | 63.0 | 63.0 | 10.5 | 438.6 | |
| 5 | trans | 1.243 | 0.1 | 0.1 | 180.0 | 480.0 |
| cis | 1.235 | 50.5 | 50.5 | 9.0 | 478.7 | |
| 6 | trans | 1.239 | 0.6 | 53.6 | 178.1 | 483.6 |
| cis | 1.230 | 50.4 | 74.3 | 6.9 | 444.5 | |
| 7 | trans | 1.239 | 10.6 | 49.8 | 179.1 | 502.8 |
| cis | 1.230 | 51.7 | 71.8 | 7.8 | 453.9 | |
| 2 | trans | 1.236 | 50.8 | 50.8 | 175.3 | 498.5 |
| cis | 1.229 | 60.5 | 60.5 | 5.1 | 474.9 |