Table 5. The O-H bond dissociation enthalpies (BDE), ionization potentials (IP), proton dissociation enthalpies (PDE), proton affinities (PA), electron transfer enthalpies (ETE) in kJ/mol obtained at B3LYP/6-311++G** level of theory.
| Parameter | 3-Hydroksyflavone | 3,7-Dihydroksyflavone | Galangin | Kaempferol | Quercetin |
|---|---|---|---|---|---|
| BDE | |||||
| Gas phase | 356.05 | 354.80 | 349.07 | 343.97 | 344.42 |
| Water | 338.02 | 332.52 | 329.25 | 323.07 | 322.74 |
| Methanol | 345.17 | 343.17 | 338.90 | 332.72 | 332.43 |
| IP | |||||
| Gas phase | 745.31 | 725.87 | 726.74 | 703.97 | 525.83 |
| Water | 477.43 | 472.30 | 465.83 | 447.35 | 444.31 |
| Methanol | 496.65 | 494.88 | 487.59 | 471.45 | 463.38 |
| PDE | |||||
| Gas phase | 926.63 | 944.82 | 938.22 | 955.90 | 1134.49 |
| Water | -17.66 | -18.04 | -14.83 | -2.52 | 0.19 |
| Methanol | 32.26 | 32.04 | 35.06 | 45.02 | 52.80 |
| PA | |||||
| Gas phase | 1413.82 | 1417.13 | 1237.98 | 1399.81 | 1397.58 |
| Water | 129.89 | 128.57 | 118.96 | 123.74 | 123.55 |
| Methanol | 183.97 | 186.30 | 175.23 | 180.05 | 179.89 |
| ETE | |||||
| Gas phase | 258.12 | 253.57 | 426.98 | 260.06 | 262.74 |
| Water | 333.02 | 328.85 | 335.18 | 324.23 | 324.09 |
| Methanol | 348.09 | 343.76 | 350.56 | 339.57 | 339.43 |