Table 1 Quantum mechanical properties of erythrosin B, berberine, and their ion-pair complex calculated using PM3 semiempirical method.
Property | Erythrosin B | Berberine | Complex | Interpretation |
|---|---|---|---|---|
Energy (Hartree) | -0.049215 | 0.126347 | -0.106927 | Complex more stable than sum of parts |
Charge | -2 | + 1 | -1 | Charge neutralization |
Dipole (D) | 12.77 | 2.83 | 25.55 | NOT additive - charge redistribution |
Polarizability α (a.u.) | 357.99 | 230.39 | 572.29 | Nearly additive (588.38 expected) |
Hyperpolarizability β (a.u.) | 5154.95 | 2012.98 | 5400.59 | Less than sum - charge delocalization |
RMS Gradient | 0.000013 | 0.000003 | 0.000006 | All well-converged |
