The molecular geometries of
all four green tea polyphenols and their radicals and anions were
optimized on the basis of the B3LYP density functional theory (DFT)
in conjunction with the 6-31G(d,p) basis set by the use of the Gaussian
03 package.22 Gas-phase bond dissociation enthalpy (BDE) and deprotonation
enthalpy (DE) were calculated as the enthalpy difference of the
processes ArOHfArO•+H• and ArOHfArO+H+, respectively.15
Relative intensities and frequencies of DFT-calculated Raman vibrational
modes were corrected following