Table 1. Calculated frontier molecular orbital energies (eV) for the title compound, its trans isomer and unsubstituted TTF and the conformational energy differences (kJ mol−1) between the cis and trans isomers.
| cis isomer | trans isomer | TTF | |
|---|---|---|---|
| E(HOMO) | −5.0559 | −5.0186 | −4.8488 |
| E(LUMO) | −1.8283 | −1.8049 | −1.1252 |
| E(HOMO-1) | −6.3966 | −6.3941 | −6.6303 |
| E(LUMO+1) | −1.6457 | −1.6515 | −0.7140 |
| ΔE(HOMO–LUMO) | 3.2275 | 3.2137 | 3.7236 |
| ΔE(HOMO-1–LUMO+1) | 4.7508 | 4.7427 | 5.9163 |
| Chemical hardness (η) | 1.6138 | 1.6068 | 1.8618 |
| Chemical potential (μ) | 3.4421 | 3.4118 | 2.9870 |
| Electronegativity (χ) | −3.4421 | −3.4118 | −2.9870 |
| Electrophilicity index (ω) | 3.6709 | 3.6221 | 2.3961 |
| ΔE(cis–trans) | 1.6331 |