Table 6. Comparative Data Showing Chemical Reactivity Descriptors (in Terms of Hartree Units) of Alanine and Alanine–Metal Complexes.
| structural parameters | αlanine | Cu2+–Ala | Zn2+–Ala | Hg2+–Ala | Cd2+–Ala |
|---|---|---|---|---|---|
| total energy (E) | –323.70 | –518.62 | –388.70 | –365.83 | –371.16 |
| EHOMO | –0.56 | –0.212 | –0.195 | –0.220 | –0.201 |
| ELUMO | –0.004 | –0.094 | –.031 | –0.033 | –0.040 |
| ΔE gap [EHOMO – ELUMO] | 0.252 | 0.119 | 0.164 | 0.187 | 0.162 |
| ionization energy IE (−εHOMO) | 0.256 | 0.212 | 0.195 | 0.220 | 0.201 |
| electron affinity EA (−εLUMO) | 0.004 | 0.094 | 0.031 | 0.033 | 0.040 |
| electronegativity χ [(IE + EA)/2] | 0.13 | 0.15 | 0.11 | 0.12 | 0.12 |
| chemical potential μ (−χ) | –0.13 | –0.15 | –0.11 | –0.12 | –0.12 |
| chemical hardness η [(IE– EA)/2] | 0.126 | 0.060 | 0.082 | 0.094 | 0.081 |
| chemical softness σ (1/η) | 7.94 | 16.80 | 12.17 | 10.70 | 12.30 |
| electrophilicity index Ω (μ2/2η) | 0.067 | 0.19 | 0.073 | 0.076 | 0.088 |