M06-2X and MN 15 methods of DFT(density functional theory)and SMD model method of self-consistent reaction field theory are used to study the mechanism of hydroxyl radical(OH)elimination by vitamin C(Vitamin C)molecules in aqueous liquid phase.The results show that Vitamin C can eliminate OH by providing hydrogen atoms to OH(OH extraction H),reacting with OH addition(OH addition to the unsaturated C of Vitamin C),and single electron transferring from Vitamin C to OH.The potential energy surface calculation shows that the energy barrier of OH extraction H ranges from 1.5 to 55.3 kJ·mol-1(mostly distributed from 1.5 to 10.8 kJ·mol-1),and the energy barrier of OH addition ranges from 0.0 to 54.7 kJ·mol-1(mostly distributed from 0.0 to 0.9 kJ)·mol-1.The barrier of electron transfers from Vitamin C to OH is 80.9 kJ·mol-1.The results show that Vitamin C is easy to react with OH in aqueous liquid phase,and Vitamin C is a good OH radical scavenger.
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