Table 3.
Theoretical structural parameters of the equilibrium structures of the styrylpyridine-like model compounds (IIIa–IIIc) calculated at the B3LYP/6-311 + G(d,p) theory level. The numbering convention is shown in Figure 1. Internuclear distances in (Å), valence and dihedral angles in (°).
| IIIa | IIIb | IIIc | ||||
|---|---|---|---|---|---|---|
|
| ||||||
| Parameter | Gas | PCM | Gas | PCM | Gas | PCM |
| 7–8 | 1.344 | 1.344 | 1.344 | 1.344 | 1.344 | 1.345 |
| 7–1 | 1.467 | 1.467 | 1.468 | 1.468 | 1.465 | 1.465 |
| 8–1′ | 1.465 | 1.465 | 1.464 | 1.465 | 1.466 | 1.466 |
| 4–3 | 1.397 | 1.397 | 1.339 | 1.402 | 1.335 | 1.338 |
| 3–2 | 1.330 | 1.332 | 1.335 | 1.337 | 1.392 | 1.391 |
| 2–1 | 1.347 | 1.349 | 1.346 | 1.346 | 1.402 | 1.403 |
| 3′–C | 1.433 | 1.432 | 1.432 | 1.432 | 1.432 | 1.431 |
| C≡N | 1.156 | 1.156 | 1.155 | 1.156 | 1.155 | 1.156 |
| 1–7–8 | 124.1 | 124.5 | 124.1 | 124.5 | 126.5 | 126.1 |
| 2–1–7 | 118.5 | 118.7 | 118.4 | 118.7 | 119.3 | 119.3 |
| 7–8–1′ | 127.1 | 127.0 | 127.2 | 127.0 | 126.9 | 126.7 |
| 2′–3′–C | 119.6 | 119.5 | 119.6 | 119.5 | 119.7 | 119.6 |
| 3′–C≡N | 180.0 | 179.9 | 179.9 | 179.9 | 179.9 | 179.9 |
| 2–1–7–8 | 0.1 | 0.0 | 0.4 | 0.1 | 179.3 | 176.9 |
| 1–7–8–1′ | 180.0 | 180.0 | 180.0 | 180.0 | 180.0 | 180.0 |
| 7–8–1′–2′ a | 0.4 | 0.3 | 0.7 | 0.2 | 179.2 | 176.6 |
| C–3–2–1 | --- | --- | 179.9 | 180.0 | --- | --- |
| 1′–2′–3′–C | 180.0 | 180.0 | 180.0 | 180.0 | 180.0 | 179.9 |
a
7–8–1′–6′ for molecule IIIc.