Table 1 Frontier orbitals energy values, reactivity descriptors and geometric aromaticity indices calculated in B3LYP/6-311 + + G(d, p) (water solution – CPCM conductor-like polarizable continuum model) for vanillic, isovanillic and o-vanillic acids and their radicals.
From: Spectroscopic, antioxidant and cytotoxicity studies of vanillic acids
VA | VA radical | isoVA | isoVA radical | o-VA | o-VA radical | |
|---|---|---|---|---|---|---|
Energy [eV] | -16619.4 | -16,602 | -16619.4 | -16,602 | -16619.5 | -16601.7 |
Dipole moment [D] | 5.5536 | 0.8054 | 4.0729 | 1.8348 | 3.4011 | 8.0616 |
EHOMO [eV] | -9.1721 | -8.1305 | -9.1330 | -8.1261 | -9.1482 | -8.3830 |
ELUMO [eV] | -5.4031 | -5.1386 | -5.5321 | -5.2640 | -5.6028 | -5.3136 |
Δ = ELUMO-EHOMO [eV] | 3.7690 | 2.9919 | 3.6009 | 2.8621 | 3.5454 | 3.0694 |
Ionisation potential I=-EHOMO | 9.1721 | 8.1305 | 9.1330 | 8.1261 | 9.1482 | 8.3830 |
Electron affinity A=-ELUMO | 5.4031 | 5.1386 | 5.5321 | 5.2640 | 5.6028 | 5.3136 |
Electroegativity Χ=(I + A)/2 | 7.2876 | 6.6345 | 7.3325 | 6.6951 | 7.3755 | 6.6295 |
Chemical potential µ=-(I + A)/2 | -7.2876 | -6.6345 | -7.3325 | -6.6951 | -7.3755 | -6.8483 |
Chemical hardness η=(I-A)/2 | 1.8845 | 1.4959 | 1.8004 | 1.4310 | 1.7727 | 1.5347 |
Chemical softness S = 1/(2η) | 0.2653 | 0.3342 | 0.2777 | 0.3494 | 0.2821 | 0.3258 |
Electrophilicity index ω = µ2/2η | 14.0909 | 14.7122 | 14.9313 | 15.6613 | 15.3434 | 15.2793 |
Aromaticity indices | ||||||
HOMA | 0.959 | 0.392 | 0.966 | 0.494 | 0.922 | 0.181 |
GEO | 0.019 | 0.392 | 0.012 | 0.311 | 0.037 | 0.532 |
EN | 0.022 | 0.216 | 0.022 | 0.195 | 0.041 | 0.287 |
I6 | 92.87 | 66.98 | 94.22 | 70.73 | 89.88 | 62.35 |
BAC | 0.874 | 0.498 | 0.900 | 0.572 | 0.856 | 0.466 |
Aj | 0.992 | 0.830 | 0.994 | 0.864 | 0.983 | 0.770 |
